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1l6rirvkr | physics | communication-systems | modulation-&-demodulation | <p>A modulating signal $$2 \sin \left(6.28 \times 10^{6}\right) t$$ is added to the carrier signal $$4 \sin \left(12.56 \times 10^{9}\right) t$$ for amplitude modulation. The combined signal is passed through a non-linear square law device. The output is then passed through a band pass filter. The bandwidth of the outp... | [] | null | 2 | $\mathrm{W}_{\mathrm{C}}=12.56 \times 10^{9}$
<br/><br/>$$
W_{m}=6.25 \times 10^{6}
$$
<br/><br/>After amplitude modulation
<br/><br/>Bandwidth frequency
<br/><br/>$$
=\frac{2 W_{m}}{2 \pi}=\frac{2 \times 6.28}{2 \pi} \times 10^{6}=2 \mathrm{MHz}
$$ | integer | jee-main-2022-online-29th-july-evening-shift | 9,658 |
ldo6rhnb | physics | communication-systems | modulation-&-demodulation | <p>Given below are two statements :</p>
<p><b>Statement I : </b>For transmitting a signal, size of antenna ( $l$ ) should be comparable to wavelength of signal (at least $l=\frac{\lambda}{4}$ in dimension)</p>
<p><b>Statement II:</b> In amplitude modulation, amplitude of carrier wave remains constant (unchanged).</p>
<... | [{"identifier": "A", "content": "Statement I is incorrect but Statement II is correct"}, {"identifier": "B", "content": "Both Statement I and Statement II are correct"}, {"identifier": "C", "content": "Both Statement I and Statement II are incorrect"}, {"identifier": "D", "content": " Statement I is correct but Stateme... | ["D"] | null | <p>For transmitting a signal, antenna should have a
size comparable to the wavelength of the signal i.e., at least
$${1 \over 4}$$ in dimension, so that the antenna properly senses the
time variation of the signal.</p>
<p>The amplitude of the carrier wave is varied in accordance
with the message signal is termed as amp... | mcq | jee-main-2023-online-31st-january-evening-shift | 9,660 |
1ldpk6s1h | physics | communication-systems | modulation-&-demodulation | <p>The amplitude of $$15 \sin (1000 \pi \mathrm{t})$$ is modulated by $$10 \sin (4 \pi \mathrm{t})$$ signal. The amplitude modulated signal contains frequency (ies) of</p>
<p>A. $$500 \mathrm{~Hz}$$</p>
<p>B. $$2 \mathrm{~Hz}$$</p>
<p>C. $$250 \mathrm{~Hz}$$</p>
<p>D. $$498 \mathrm{~Hz}$$</p>
<p>E. $$502 \mathrm{~Hz}$$... | [{"identifier": "A", "content": "B only"}, {"identifier": "B", "content": "A only"}, {"identifier": "C", "content": "A, D and E only"}, {"identifier": "D", "content": "A and B only"}] | ["C"] | null | Carrier wave frequency
<br/><br/>$\mathrm{V}_{\mathrm{C}}=\frac{1000 \pi}{2 \pi}=500 \mathrm{~Hz}$
<br/><br/>Modulating wave frequency
<br/><br/>$\mathrm{V}_{\mathrm{m}}=\frac{4 \pi}{2 \pi}=2 \mathrm{~Hz}$
<br/><br/>The amplitude modulated signal contains frequencies
<br/><br/>$= \mathrm{V}_{\mathrm{C}}-\mathrm{V}_... | mcq | jee-main-2023-online-31st-january-morning-shift | 9,661 |
1ldr1iwim | physics | communication-systems | modulation-&-demodulation | <p>A sinusoidal carrier voltage is amplitude modulated. The resultant amplitude modulated wave has maximum and minimum amplitude of $$120 \mathrm{~V}$$ and $$80 \mathrm{~V}$$ respectively. The amplitude of each sideband is :</p> | [{"identifier": "A", "content": "15 V"}, {"identifier": "B", "content": "20 V"}, {"identifier": "C", "content": "5 V"}, {"identifier": "D", "content": "10 V"}] | ["D"] | null | <p>Amplitude of each side band = $$\frac{A_{\mathrm{message}}}{2}$$</p>
<p>$$\mathrm{A_{carrier}+A_{message}=120}$$ ............ (1)</p>
<p>$$\mathrm{A_{carrier}-A_{message}=80}$$ .............. (2)</p>
<p>From (1) and (2)</p>
<p>$$\mathrm{A_{message}=20~V}$$</p>
<p>$$\therefore$$ Amplitude of each side band = 10 V</p> | mcq | jee-main-2023-online-30th-january-morning-shift | 9,663 |
1ldsa0gr4 | physics | communication-systems | modulation-&-demodulation | <p>The modulation index for an A.M. wave having maximum and minimum peak-to-peak voltages of 14 mV and 6 mV respectively is-</p> | [{"identifier": "A", "content": "0.4"}, {"identifier": "B", "content": "0.6"}, {"identifier": "C", "content": "1.4"}, {"identifier": "D", "content": "0.2"}] | ["A"] | null | <p>The modulation index (m) of an amplitude-modulated wave is defined as the ratio of the amplitude of the modulating signal to the amplitude of the carrier wave. It is a measure of the degree of modulation of the carrier wave and is given by the following equation:</p>
$$ m = \frac{V_{max} - V_{min}}{V_{max} + V_{min... | mcq | jee-main-2023-online-29th-january-evening-shift | 9,664 |
1lduhnwsf | physics | communication-systems | modulation-&-demodulation | <p>A message signal of frequency 5 kHz is used to modulate a carrier signal of frequency 2 MHz. The bandwidth for amplitude modulation is :</p> | [{"identifier": "A", "content": "10 kHz"}, {"identifier": "B", "content": "2.5 kHz"}, {"identifier": "C", "content": "20 kHz"}, {"identifier": "D", "content": "5 kHz"}] | ["A"] | null | Given<br/><br/>
Signal frequency f<sub>m</sub> = 5kHz<br/><br/>
Carrier wave frequency $f_c=2 \mathrm{MHz}$
$$
\mathrm{f}_{\mathrm{c}}=2000 \mathrm{KHz}
$$<br/><br/>
The resultant signal will have band width of frequency given by<br/><br/>
$$
\begin{aligned}
& {\left[\left(f_c+f_m\right)-\left(f_c-f_m\right)\right]} \\... | mcq | jee-main-2023-online-25th-january-morning-shift | 9,665 |
1lgvs231a | physics | communication-systems | modulation-&-demodulation | <p>A message signal of frequency $$3 ~\mathrm{kHz}$$ is used to modulate a carrier signal of frequency $$1.5 ~\mathrm{MHz}$$. The bandwidth of the amplitude modulated wave is</p> | [{"identifier": "A", "content": "$$6 ~\\mathrm{MHz}$$"}, {"identifier": "B", "content": "$$6 ~\\mathrm{kHz}$$"}, {"identifier": "C", "content": "$$3 ~\\mathrm{MHz}$$"}, {"identifier": "D", "content": "$$3 ~\\mathrm{kHz}$$"}] | ["B"] | null | <p>The bandwidth of an amplitude-modulated wave is given by $$2B$$, where $$B$$ is the bandwidth of the modulating signal.<br/><br/> In this case, the modulating signal is a message signal of frequency $$3~\mathrm{kHz}$$, so the bandwidth of the amplitude modulated wave is $$2(3~\mathrm{kHz})=6~\mathrm{kHz}$$. </p>
<p>... | mcq | jee-main-2023-online-10th-april-evening-shift | 9,668 |
1lgxwv754 | physics | communication-systems | modulation-&-demodulation | <p>A carrier wave of amplitude 15 V is modulated by a sinusoidal base band signal of magnitude 3 V. The ratio of maximum amplitude to minimum amplitude in an amplitude modulated wave is</p> | [{"identifier": "A", "content": "1"}, {"identifier": "B", "content": "5"}, {"identifier": "C", "content": "2"}, {"identifier": "D", "content": "$$\\frac{3}{2}$$"}] | ["D"] | null | The maximum and minimum amplitude of a modulated wave are given by:
<br/><br/>
Maximum amplitude = carrier wave amplitude + base band signal magnitude = 15V + 3V = 18V
<br/><br/>
Minimum amplitude = carrier wave amplitude - base band signal magnitude = 15V - 3V = 12V
<br/><br/>
Therefore, the ratio of maximum amplitude... | mcq | jee-main-2023-online-10th-april-morning-shift | 9,669 |
1lh30tspu | physics | communication-systems | modulation-&-demodulation | <p>For an amplitude modulated wave the minimum amplitude is $$3 \mathrm{~V}$$, while the modulation index is $$60 \%$$. The maximum amplitude of the modulated wave is:</p> | [{"identifier": "A", "content": "5 V"}, {"identifier": "B", "content": "12 V"}, {"identifier": "C", "content": "10 V"}, {"identifier": "D", "content": "15 V"}] | ["B"] | null | <p>In the case of Amplitude Modulation, the modulation index (µ) can also be represented as:</p>
<p>$$ \mu = \frac{A_{\max} - A_{\min}}{A_{\max} + A_{\min}} $$</p>
<p>where:</p>
<ul>
<li>$A_{\max}$ is the maximum amplitude of the modulated wave,</li>
<li>$A_{\min}$ is the minimum amplitude of the modulated wave.</li>
<... | mcq | jee-main-2023-online-6th-april-evening-shift | 9,670 |
pwzy6k7ViJIi5kOotg3HX | physics | current-electricity | color-coding-of-resistance | A resistance is shown in the figure. Its value and tolerance are given respectively by :
<br/><br/><img src="data:image/png;base64,UklGRr4MAABXRUJQVlA4ILIMAACQrQCdASoAA4ABP4G+12U2L6wnIZIp2sAwCWlu4Wzz5mNwvH6PtIbRPuP/keO5hG7/ymjoov//1nff4mkWhbKrLQtlVloWyqy0LZVZaFsqstC2TdQ4AuFa8hE91av292GPvzl7sMg7YvWQ95LMr9Lwe+9bGPWlr4jR... | [{"identifier": "A", "content": "270 $$\\Omega $$, 10 %"}, {"identifier": "B", "content": "27 k$$\\Omega $$, 10 %"}, {"identifier": "C", "content": "27 k$$\\Omega $$, 20 %"}, {"identifier": "D", "content": "270 $$\\Omega $$, 5 %"}] | ["B"] | null | From color code table :
<br><br>For Red value is 2
<br><br>For Violet value is 7
<br><br>For Orange multiplier is 10<sup>3</sup>
<br><br>For Silver tolarence is 10%
<br><br>$$ \therefore $$ Resistance and tolerance is
<br><br>= 27 $$ \times $$ 10<sup>3</sup> $$ \pm $$ 10%
<br><br>= 27 k$$\Omega $$ $$ \pm $$ 10% | mcq | jee-main-2019-online-9th-january-morning-slot | 9,671 |
Ae3Yiz5Vr8aG4Z4LNrrtw | physics | current-electricity | color-coding-of-resistance | A carbon resistance has a following colour code. What is the value of the resistance ?
<br/><br/><img src="data:image/png;base64,UklGRpQKAABXRUJQVlA4IIgKAACwWwCdASoAA8kAPm02mUikIyKhIVR6EIANiWlu6BYJB0WuuqNH6+f4juC/3fDLcp5nloK7Kdrn7pOGAAB9TvOJ+680Prprtf2/1BvKM/1PLB9b+woKqmVDIOIeJFp8zf6sukaGPvI2riA1BE7Ezd+BAr9X/9UzSrWuxM... | [{"identifier": "A", "content": "530 k$$\\Omega $$ $$ \\pm $$ 5%"}, {"identifier": "B", "content": "5.3 M$$\\Omega $$ $$ \\pm $$ 5%"}, {"identifier": "C", "content": "6.4 M$$\\Omega $$ $$ \\pm $$ 5%"}, {"identifier": "D", "content": "64 k$$\\Omega $$ $$ \\pm $$ 10%"}] | ["A"] | null | From colour coding table, <br/>
<br>Green line represents number = 5<br/>
<br>Orange line represents number = 3<br/>
<br>Yellow line represent multiplier = 10<sup>4</sup><br/>
<br>Golden line represents tollerence = $$ \pm $$ 5%
<br><br>$$ \therefore $$ Resistance = 53 $$ \times $$ 10<sup>4</sup> $$ \... | mcq | jee-main-2019-online-9th-january-evening-slot | 9,672 |
cYZfAZLyahGGq6g75aFU1 | physics | current-electricity | color-coding-of-resistance | A 200 $$\Omega $$ resistor has a certain color code. If one
replaces the red color by green in the code, the
new resistance will be : | [{"identifier": "A", "content": "500 $$\\Omega $$"}, {"identifier": "B", "content": "100 $$\\Omega $$"}, {"identifier": "C", "content": "200 $$\\Omega $$"}, {"identifier": "D", "content": "300 $$\\Omega $$"}] | ["A"] | null | 200 $$\Omega $$ = Red + Black + Brown<br><br>
Green = 5<br><br>
So, Green + Black + Brown = 500 $$\Omega $$ | mcq | jee-main-2019-online-8th-april-morning-slot | 9,673 |
1ktflr2az | physics | current-electricity | color-coding-of-resistance | The Colour coding on a carbon resistor is shown in the given figure. The resistance value of the given resistor is :<br/><br/><img src="data:image/png;base64,UklGRpwNAABXRUJQVlA4IJANAABQXACdASqjAegAPm0ylkikIqKhItFqkIANiWlu4XExG/OH8OfzHtN/uH5L+JD57+v/kr6r1X3/T/zP1S+Yb3/+Rf0P/f/0z5yfqn93/jv82/vnpD74/FX4CPVX+K/jv9M/3H9l9L... | [{"identifier": "A", "content": "(5700 $$\\pm$$ 285) $$\\Omega$$"}, {"identifier": "B", "content": "(7500 $$\\pm$$ 750) $$\\Omega$$"}, {"identifier": "C", "content": "(5700 $$\\pm$$ 375) $$\\Omega$$"}, {"identifier": "D", "content": "(7500 $$\\pm$$ 375) $$\\Omega$$"}] | ["D"] | null | R = 75 $$\times$$ 10<sup>2</sup> $$\pm$$ 5% of 7500<br><br>R = (7500 $$\pm$$ 375) $$\Omega$$ | mcq | jee-main-2021-online-27th-august-evening-shift | 9,674 |
FQ8Cd8K46xAOvsY92GHFC | physics | current-electricity | combination-of-resistances | In the given circuit all resistances are of value $$R$$ $$ohm$$ each. The equivalent resistance between $$A$$ and $$B$$ is :
<br/><br/><img src="data:image/png;base64,UklGRkwVAABXRUJQVlA4IEAVAACwBQGdASoAA8wBP4HA2GO2MSymo1WqAsAwCWlu62Ay75RtGSnD6B/21rzl//9z229uf7N3wPVfiCuCPtP//6MH/nf+vZf//9YX38Mjbu7u7u7u7u7u7u7u7uyxVEXI... | [{"identifier": "A", "content": "$$2R$$ "}, {"identifier": "B", "content": "$$3R$$ "}, {"identifier": "C", "content": "$${{5R} \\over 3}$$ "}, {"identifier": "D", "content": "$${{5R} \\over 2}$$"}] | ["A"] | null | <picture><source media="(max-width: 320px)" srcset="https://res.cloudinary.com/dckxllbjy/image/upload/v1734267612/exam_images/eslsq0gsencxwzw6pnhq.webp"><source media="(max-width: 500px)" srcset="https://res.cloudinary.com/dckxllbjy/image/upload/v1734264243/exam_images/yyvj4ysqf2bvbipv2xs8.webp"><source media="(max-wid... | mcq | jee-main-2018-online-15th-april-morning-slot | 9,676 |
TZXJHD7uRp6v3fzvrYjS1 | physics | current-electricity | combination-of-resistances | A wire of resistance R is bent to form a square
ABCD as shown in the figure. The effective
resistance between E and C is :
(E is mid-point of arm CD)
<img src="data:image/png;base64,UklGRs4DAABXRUJQVlA4IMIDAABwSACdASrsAj4BP4HA32a2MS8noHRomsAwCWlu4XdOABnZ1+fqA+mtlEY0qxb1RHbNPhCR9Y82pp8ISPrHm1NPhCR9Y82pp8ISLGAMzQ2BZqEEB8... | [{"identifier": "A", "content": "$${7 \\over {64}}R$$"}, {"identifier": "B", "content": "$${1 \\over {16}}R$$"}, {"identifier": "C", "content": "R"}, {"identifier": "D", "content": "$${3 \\over {4}}R$$"}] | ["A"] | null | $${1 \over {{R_{eq}}}} = {8 \over {7R}} + {8 \over R}$$<br><br>
$${1 \over {{R_{eq}}}} = {{8 + 56} \over {7R}};{R_{eq}} = {{7R} \over {64}}$$ | mcq | jee-main-2019-online-9th-april-morning-slot | 9,677 |
hYGjyeHl2OTqO98KEbvkk | physics | current-electricity | combination-of-resistances | A uniform metallic wire has a resistance of 18 $$\Omega $$ and is bent into an equilateral triangle. Then, the resistance between any two vertices of the triangle is -
| [{"identifier": "A", "content": "12 $$\\Omega $$"}, {"identifier": "B", "content": "2 $$\\Omega $$"}, {"identifier": "C", "content": "4 $$\\Omega $$"}, {"identifier": "D", "content": "8 $$\\Omega $$"}] | ["C"] | null | <img src="https://res.cloudinary.com/dckxllbjy/image/upload/v1734264047/exam_images/t8ovjuqhs3at5ofuad56.webp" style="max-width: 100%; height: auto;display: block;margin: 0 auto;" loading="lazy" alt="JEE Main 2019 (Online) 10th January Morning Slot Physics - Current Electricity Question 257 English Explanation">
<br><... | mcq | jee-main-2019-online-10th-january-morning-slot | 9,678 |
6IjIH2u0UVecFLCHeO1kmj47wr2 | physics | current-electricity | combination-of-resistances | The equivalent resistance of series combination of two resistors is 's'. When they are connected in parallel, the equivalent resistance is 'p'. If s = np, then the minimum value for n is ____________. (Round off to the Nearest Integer) | [] | null | 4 | $$s = np$$<br><br>$${R_1} + {R_2} = n\left[ {{{{R_1}{R_2}} \over {{R_1} + {R_2}}}} \right]$$<br><br>$$ \Rightarrow $$ $$R_1^2 + R_2^2 + 2{R_1}{R_2} = n{R_1}{R_2}$$<br><br>$$ \Rightarrow $$ $$R_1^2 + (2 - n){R_1}{R_2} + R_2^2 = 0$$
<br><br>For real roots, b<sup>2</sup> - 4ac $$ \ge $$ 0
<br><br> $${[(2 - n){R_2}]^2} - 4... | integer | jee-main-2021-online-17th-march-morning-shift | 9,679 |
OAKFczhSJhHOnGdgjt1kmlwk75h | physics | current-electricity | combination-of-resistances | Two wires of same length and thickness having specific resistances 6$$\Omega$$ cm and 3$$\Omega$$ cm respectively are connected in parallel. The effective resistivity is $$\rho$$$$\Omega$$ cm. The value of $$\rho$$, to the nearest integer, is ____________. | [] | null | 4 | Let length of each wire is l and area A. When they are connected in parallel then their effective area 2A.<br><br>From formula we know,<br><br>$${R_{eq}} = {{{R_1}{R_2}} \over {{R_1} + {R_2}}}$$<br><br>$$ \Rightarrow {{\rho l} \over {2A}} = {{{\rho _1}{l \over A} \times {\rho _2}{l \over A}} \over {{\rho _1}{l \over A}... | integer | jee-main-2021-online-18th-march-evening-shift | 9,681 |
1krqem0kb | physics | current-electricity | combination-of-resistances | In the given figure switches S<sub>1</sub> and S<sub>2</sub> are in open condition. The resistance across ab when the switches S<sub>1</sub> and S<sub>2</sub> are closed is _____________ $$\Omega$$.<br/><br/><img src="data:image/png;base64,UklGRnISAABXRUJQVlA4IGYSAABQcACdASpDAr8APm02l0ikIyKhIvLaOIANiWlu4WxhG/Np8Q/0b+df... | [] | null | 10 | When switch S<sub>1</sub> and S<sub>2</sub> are closed<br><br> <img src="https://app-content.cdn.examgoal.net/fly/@width/image/1l46x5no7/ab83da9e-9598-44ac-9c2e-b6905a212f86/d9f6c270-e7e4-11ec-9570-5bc44f917fce/file-1l46x5no8.png?format=png" data-orsrc="https://app-content.cdn.examgoal.net/image/1l46x5no7/ab83da9e-9598... | integer | jee-main-2021-online-20th-july-evening-shift | 9,682 |
1krstwl6g | physics | current-electricity | combination-of-resistances | A Copper (Cu) rod of length 25 cm and cross-sectional area 3 mm<sup>2</sup> is joined with a similar Aluminium (Al) rod as shown in figure. Find the resistance of the combination between the ends A and B.<br/><br/>(Take Resistivity of Copper = 1.7 $$\times$$ 10<sup>$$-$$8</sup> $$\Omega$$m and Resistivity of Aluminium ... | [{"identifier": "A", "content": "0.0858 m$$\\Omega$$"}, {"identifier": "B", "content": "1.420 m$$\\Omega$$"}, {"identifier": "C", "content": "0.858 m$$\\Omega$$"}, {"identifier": "D", "content": "2.170 m$$\\Omega$$"}] | ["C"] | null | $${R_{Cu}} = {{{\rho _{Cu}} \times l} \over A}$$<br><br>$${R_{Al}} = {{{\rho _{Al}} \times l} \over A}$$<br><br>$${R_{Eq}} = {{{\rho _{Cu}} \times {\rho _{Al}}} \over {{\rho _{Cu}} + {\rho _{Al}}}} \times \left( {{l \over A}} \right)$$<br><br>$$ = {{1.7 \times {{10}^{ - 8}} \times 2.6 \times {{10}^{ - 8}}} \over {(1.7 ... | mcq | jee-main-2021-online-22th-july-evening-shift | 9,683 |
1ktaey9sd | physics | current-electricity | combination-of-resistances | What equal length of an iron wire and a copper-nickel alloy wire, each of 2 mm diameter connected parallel to give an equivalent resistance of 3$$\Omega$$ ?<br/><br/>(Given resistivities of iron and copper-nickel alloy wire are 12 $$\mu$$$$\Omega$$ and 51 $$\mu$$$$\Omega$$ cm respectively) | [{"identifier": "A", "content": "82 m"}, {"identifier": "B", "content": "97 m"}, {"identifier": "C", "content": "110 m"}, {"identifier": "D", "content": "90 m"}] | ["B"] | null | $${{{R_1}{R_2}} \over {{R_1} + {R_2}}} = 3$$<br><br>$${{{{(12 \times {{10}^{ - 6}} \times {{10}^{ - 2}})} \over {\pi {{(2)}^2} \times {{10}^{ - 6}}}} \times {{(51 \times {{10}^{ - 6}} \times {{10}^{ - 2}})l \times 4} \over {\pi {{(2)}^2} \times {{10}^{ - 6}}}}} \over {{{63 \times {{10}^{ - 6}} \times {{10}^{ - 2}} \tim... | mcq | jee-main-2021-online-26th-august-morning-shift | 9,684 |
1ktbo0umg | physics | current-electricity | combination-of-resistances | If you are provided a set of resistances 2$$\Omega$$, 4$$\Omega$$, 6$$\Omega$$ and 8$$\Omega$$. Connect these resistances so as to obtain an equivalent resistance of $${{46} \over 3}$$$$\Omega$$. | [{"identifier": "A", "content": "4$$\\Omega$$ and 6$$\\Omega$$ are in parallel with 2$$\\Omega$$ and 8$$\\Omega$$ in series"}, {"identifier": "B", "content": "6$$\\Omega$$ and 8$$\\Omega$$ are in parallel with 2$$\\Omega$$ and 4$$\\Omega$$ in series"}, {"identifier": "C", "content": "2$$\\Omega$$ and 6$$\\Omega$$ are i... | ["D"] | null | <picture><source media="(max-width: 320px)" srcset="https://res.cloudinary.com/dckxllbjy/image/upload/v1734263514/exam_images/rvjgxpvupxphgwvv8p2p.webp"><source media="(max-width: 500px)" srcset="https://res.cloudinary.com/dckxllbjy/image/upload/v1734265371/exam_images/twadgajhu9zvucdout6y.webp"><source media="(max-wid... | mcq | jee-main-2021-online-26th-august-evening-shift | 9,685 |
1kte6mrk0 | physics | current-electricity | combination-of-resistances | Five identical cells each of internal resistance 1$$\Omega$$ and emf 5V are connected in series and in parallel with an external resistance 'R'. For what value of 'R', current in series and parallel combination will remain the same? | [{"identifier": "A", "content": "1 $$\\Omega$$"}, {"identifier": "B", "content": "25 $$\\Omega$$ "}, {"identifier": "C", "content": "5 $$\\Omega$$"}, {"identifier": "D", "content": "10 $$\\Omega$$ "}] | ["A"] | null | $${i_1} = {{25} \over {5 + R}}$$<br><br>$${i_2} = {5 \over {R + {1 \over 5}}}$$<br><br>$${i_1} = {i_2} \Rightarrow 5\left( {R + {1 \over 5}} \right) = 5 + R$$<br><br>4R = R<br><br>R = 1$$\Omega$$ | mcq | jee-main-2021-online-27th-august-morning-shift | 9,686 |
1ktfoh3mo | physics | current-electricity | combination-of-resistances | The ratio of the equivalent resistance of the network (shown in figure) between the points a and b when switch is open and switch is closed is x : 8. The value of x is ___________.<br/><br/><img src="data:image/png;base64,"/> | [] | null | 9 | $${R_{eq\,open}} = {{3R} \over 2}$$<br><br>$${R_{eq\,closed}} = 2 \times {{R \times 2R} \over {3R}} = {{4R} \over 3}$$<br><br>$${{{R_{eq\,open}}} \over {{R_{eq\,closed}}}} = {{3R} \over 2} \times {3 \over {4R}} = {9 \over 8}$$<br><br>$$\therefore$$ $$x = 9$$ | integer | jee-main-2021-online-27th-august-evening-shift | 9,688 |
1kth5w3sg | physics | current-electricity | combination-of-resistances | A square shaped wire with resistance of each side 3$$\Omega$$ is bent to form a complete circle. The resistance between two diametrically opposite points of the circle in unit of $$\Omega$$ will be ___________. | [] | null | 3 | <img src="https://res.cloudinary.com/dckxllbjy/image/upload/v1734265899/exam_images/f6xutcotw2gnkr6gsjjp.webp" style="max-width: 100%;height: auto;display: block;margin: 0 auto;" loading="lazy" alt="JEE Main 2021 (Online) 31st August Morning Shift Physics - Current Electricity Question 154 English Explanation"><br>R<su... | integer | jee-main-2021-online-31st-august-morning-shift | 9,689 |
1kth62r3q | physics | current-electricity | combination-of-resistances | The voltage drop across 15$$\Omega$$ resistance in the given figure will be ______________ V.<br/><br/><img src="data:image/png;base64,UklGRqAVAABXRUJQVlA4IJQVAAAwqgCdASqLAmcBP4G+12Q2MCwmo9I5qsAwCWlu/HyY4OtQ2f1J/4HcJriuUeX/7AP7rvP/a/ECyc60Ht/MCv78De9X5/95vQF8o7/i8pH7p/5fTP6343QgJLE1ht4XostSPLZ7hHQKqYJQ6uk7mqZkO0erFxxPx... | [] | null | 6 | <img src="https://res.cloudinary.com/dckxllbjy/image/upload/v1734264752/exam_images/cnracw2eaqxedggjvmm7.webp" style="max-width: 100%;height: auto;display: block;margin: 0 auto;" loading="lazy" alt="JEE Main 2021 (Online) 31st August Morning Shift Physics - Current Electricity Question 152 English Explanation 1"><br><b... | integer | jee-main-2021-online-31st-august-morning-shift | 9,690 |
1ktjp4x6w | physics | current-electricity | combination-of-resistances | The equivalent resistance of the given circuit between the terminals A and B is :<br/><br/><img src="data:image/png;base64,UklGRoATAABXRUJQVlA4IHQTAABwcgCdASppArgAPm02lkikIqUhIhI60KANiWlu8p8dsKfiN+cz4W/jH43eBX9m/JP0H/GPnn6//Wv2K/sn7Ke95/C/wDqW/6P+S92F7L/Ff5f/vv7H62/3z+Of0v/O/2/0h9/3xB7AvqP+yfxv+mf73+telX/Zfyn+e9/jV3/I/... | [{"identifier": "A", "content": "0$$\\Omega$$"}, {"identifier": "B", "content": "3$$\\Omega$$"}, {"identifier": "C", "content": "$${9 \\over 2}$$$$\\Omega$$"}, {"identifier": "D", "content": "1$$\\Omega$$"}] | ["D"] | null | On simplification
<br><img src="https://res.cloudinary.com/dckxllbjy/image/upload/v1734264690/exam_images/tufiglhmwbjranajvkfn.webp" style="max-width: 100%;height: auto;display: block;margin: 0 auto;" loading="lazy" alt="JEE Main 2021 (Online) 31st August Evening Shift Physics - Current Electricity Question 147 English... | mcq | jee-main-2021-online-31st-august-evening-shift | 9,691 |
1ktmoalrp | physics | current-electricity | combination-of-resistances | Two resistors R<sub>1</sub> = (4 $$\pm$$ 0.8) $$\Omega$$ and R<sub>2</sub> = (4 $$\pm$$ 0.4) $$\Omega$$ are connected in parallel. The equivalent resistance of their parallel combination will be : | [{"identifier": "A", "content": "(4 $$\\pm$$ 0.4) $$\\Omega$$"}, {"identifier": "B", "content": "(2 $$\\pm$$ 0.4) $$\\Omega$$"}, {"identifier": "C", "content": "(2 $$\\pm$$ 0.3) $$\\Omega$$"}, {"identifier": "D", "content": "(4 $$\\pm$$ 0.3) $$\\Omega$$"}] | ["C"] | null | Given, <br/><br/>R<sub>1</sub> = (4 $$\pm$$ 0.8) $$\Omega$$<br/><br/>R<sub>2</sub> = (4 $$\pm$$ 0.4) $$\Omega$$<br/><br/>Equivalent resistance when the resistors are connected in parallel is given by<br/><br/>$${1 \over {{R_{eq}}}} = {1 \over {{R_1}}} + {1 \over {{R_2}}} \Rightarrow {1 \over {{R_{eq}}}} = {1 \over 4} +... | mcq | jee-main-2021-online-1st-september-evening-shift | 9,692 |
1l56wkk9o | physics | current-electricity | combination-of-resistances | <p>In the given circuit 'a' is an arbitrary constant. The value of m for which the equivalent circuit resistance is minimum, will be $$\sqrt {{x \over 2}} $$. The value of x is __________.</p>
<p> <img src="data:image/png;base64,UklGRrQLAABXRUJQVlA4IKgLAAAwsgCdASoAA70BP4G+12W2L6wnIXGpusAwCWlu4WrjgmNwvV6K/0Pg9xS7PnuX3bv... | [] | null | 3 | <p>$${R_{net}} = {{ma} \over 3} + {a \over {2m}}$$</p>
<p>$$ = a\left[ {{m \over 3} + {1 \over {2m}} - {2 \over {\sqrt 6 }} + {2 \over {\sqrt 6 }}} \right]$$</p>
<p>$$ = a\left[ {{{\left( {\sqrt {{m \over 3}} - {1 \over {\sqrt {2m} }}} \right)}^2} + \sqrt {{2 \over 3}} } \right]$$</p>
<p>This will be minimum when</p>
... | integer | jee-main-2022-online-27th-june-evening-shift | 9,693 |
1l58ht5hi | physics | current-electricity | combination-of-resistances | <p>The equivalent resistance between points A and B in the given network is :</p>
<p> <img src="data:image/png;base64,UklGRkwYAABXRUJQVlA4IEAYAACQNwGdASoAAzQCP4HA2WO2MSymo5QZosAwCWlu/FNYS4pnZ18fs1/wt4fVm4h/k//jvup5O3Pz49CNDU168PXoK//+rn9N//72Y///Vh99i2L4KVHaVDIQEqOQXB4JpC365XMmt8QXVIJTw3AHsFh8tfzBdbKhkICVHHmF3jjFaVB6TG... | [{"identifier": "A", "content": "65$$\\Omega$$"}, {"identifier": "B", "content": "20$$\\Omega$$"}, {"identifier": "C", "content": "5$$\\Omega$$"}, {"identifier": "D", "content": "2$$\\Omega$$"}] | ["C"] | null | <p>Initially 5 $$\Omega$$ and 5 $$\Omega$$ are in series and then in parallel with 10 $$\Omega$$ this pattern continues thus</p>
<p><img src="https://app-content.cdn.examgoal.net/fly/@width/image/1l5jy3pdo/796acda4-ed03-4705-aaf1-ed6b84574375/f49d77c0-02da-11ed-b2c8-3573db55a50d/file-1l5jy3pdp.png?format=png" data-orsr... | mcq | jee-main-2022-online-26th-june-evening-shift | 9,694 |
1l5alfdcm | physics | current-electricity | combination-of-resistances | <p>The total current supplied to the circuit as shown in figure by the 5 V battery is ____________ A.</p>
<p><img src="data:image/png;base64,UklGRmgSAABXRUJQVlA4IFwSAAAwCgGdASoAA/IBP4HA2mQ2MK0mo7P5SsAwCWlu/E84aJSHZ18ftT/wPVfeLsh8Uf0//5v3e1P5cKeGvnoEef/Tsqre5b//9aP3+KVZZGaxyIzWOQ9SchS3AvaRmYY1ijxyLlndMVUEkZodJApEuZl7uS6... | [] | null | 2 | <p>The equivalent circuit is</p>
<p><img src="https://app-content.cdn.examgoal.net/fly/@width/image/1l5ky7hbp/8d335d28-cde1-4647-afff-6e9a16fec32b/26479160-0368-11ed-af51-374257f3e209/file-1l5ky7hbq.png?format=png" data-orsrc="https://app-content.cdn.examgoal.net/image/1l5ky7hbp/8d335d28-cde1-4647-afff-6e9a16fec32b/264... | integer | jee-main-2022-online-25th-june-morning-shift | 9,695 |
1l5bbp882 | physics | current-electricity | combination-of-resistances | <p>What will be the most suitable combination of three resistors A = 2$$\Omega$$, B = 4$$\Omega$$, C = 6$$\Omega$$ so that $$\left( {{{22} \over 3}} \right)$$$$\Omega$$ is equivalent resistance of combination?</p> | [{"identifier": "A", "content": "Parallel combination of A and C connected in series with B."}, {"identifier": "B", "content": "Parallel combination of A and B connected in series with C."}, {"identifier": "C", "content": "Series combination of A and C connected in parallel with B."}, {"identifier": "D", "content": "Se... | ["B"] | null | <p>$${R_{eq}} = {{2 \times 4} \over {2 + 6}} + 6 = {{22} \over 3}$$</p>
<p>$$\Rightarrow$$ A and B are in parallel and C is in series.</p> | mcq | jee-main-2022-online-24th-june-evening-shift | 9,696 |
1l5w2z0ak | physics | current-electricity | combination-of-resistances | <p>An electric cable of copper has just one wire of radius 9 mm. Its resistance is 14 $$\Omega$$. If this single copper wire of the cable is replaced by seven identical well insulated copper wires each of radius 3 mm connected in parallel, then the new resistance of the combination will be :</p> | [{"identifier": "A", "content": "9 $$\\Omega$$"}, {"identifier": "B", "content": "18 $$\\Omega$$"}, {"identifier": "C", "content": "28 $$\\Omega$$"}, {"identifier": "D", "content": "126 $$\\Omega$$"}] | ["B"] | null | <p>Initially, copper wire radius (r<sub>1</sub>) = 9 mm</p>
<p>Resistance (R) = 14 $$\Omega$$</p>
<p>We know, $$R = {{\rho L} \over A} = {{\rho L} \over {\pi r_1^2}} = 14$$</p>
<p>Now this copper wire is replaced by 7 parallel copper wire of resistance R<sub>1</sub>.</p>
<p>$$\therefore$$ Equivalent resistance of 7 par... | mcq | jee-main-2022-online-30th-june-morning-shift | 9,697 |
1l6e08xkz | physics | current-electricity | combination-of-resistances | <p>Eight copper wire of length $$l$$ and diameter $$d$$ are joined in parallel to form a single composite conductor of resistance $$R$$. If a single copper wire of length $$2 l$$ have the same resistance $$(R)$$ then its diameter will be ____________ d.</p> | [] | null | 4 | <p><img src="https://app-content.cdn.examgoal.net/fly/@width/image/1l6tdw0df/66410f4a-df19-4dd2-9891-92bd65da2bc2/f5ec8330-1bd7-11ed-a7b0-d7e65118bbd8/file-1l6tdw0dg.png?format=png" data-orsrc="https://app-content.cdn.examgoal.net/image/1l6tdw0df/66410f4a-df19-4dd2-9891-92bd65da2bc2/f5ec8330-1bd7-11ed-a7b0-d7e65118bbd8... | integer | jee-main-2022-online-25th-july-morning-shift | 9,698 |
1l6p66e6u | physics | current-electricity | combination-of-resistances | <p>The current I flowing through the given circuit will be __________A.</p>
<p><img src="data:image/png;base64,UklGRgAIAABXRUJQVlA4IPQHAABQhQCdASoAA2gBP4HA2GW2MCynIROpssAwCWlu/Eb3nXYnZ1+/s5aa2etyv5n///1blr/jR4QiY0MY9aSrq94FTAqmRDHrSVdXvAqXu/+5OfQosrZpQwoqnE4sWw/GuqIsrZpQwosqpRXI5HI5HI5HJlTOZ8BqZoiaORyORyaFg4f9xOFqYfFbH... | [] | null | 2 | <p>All $$9 ~\Omega$$ resistances are in parallel</p>
<p>$${R_{eq}} = 3\,\Omega $$</p>
<p>$$I = {6 \over 3}A = 2A$$</p> | integer | jee-main-2022-online-29th-july-morning-shift | 9,699 |
1ldujr9xe | physics | current-electricity | combination-of-resistances | <p>In the given circuit, the equivalent resistance between the terminal A and B is __________ $$\Omega$$.</p>
<p><img src="data:image/png;base64,UklGRgoQAABXRUJQVlA4IP4PAAAQ5QCdASoAAwcCP4HA2mS2MLqnIpQ5Y1AwCWlu/CiX4K9klB7iaLt/sZuY2escW3b3E7snq0wT1e/Qfh/vZX/+9VBj6v+NKmqQSu/EB1NyPkg4J6CW6LMRdxQCdak3MxA297aKGFF8ggOpDYmJRGw... | [] | null | 10 | <p><img src="https://app-content.cdn.examgoal.net/fly/@width/image/1ldvay5md/964b31f5-b032-484c-963b-6d770f482c22/8b290250-a77b-11ed-a5e3-ff739bca566a/file-1ldvay5me.png?format=png" data-orsrc="https://app-content.cdn.examgoal.net/image/1ldvay5md/964b31f5-b032-484c-963b-6d770f482c22/8b290250-a77b-11ed-a5e3-ff739bca566a... | integer | jee-main-2023-online-25th-january-morning-shift | 9,701 |
1lgxxx9ci | physics | current-electricity | combination-of-resistances | <p>The equivalent resistance of the circuit shown below between points a and b is :</p>
<p><img src="data:image/png;base64,UklGRuAWAABXRUJQVlA4INQWAACwMQGdASoAA14CP4G41WW2LT+nIlAps/AwCWlu/CHYEWVHZ18ftL6KbmLko8D83aFu3vx/9MZBW1+9AjzP6PMjX/6vZP//9Q332KHgBJCmAAkhTAASCi5rN0GZWXjCqzPoUwAEkKYACQpepwBnJywx9+svU3+Ynn5oeASgk7qyM... | [{"identifier": "A", "content": "16$$\\Omega$$"}, {"identifier": "B", "content": "20$$\\Omega$$"}, {"identifier": "C", "content": "3.2$$\\Omega$$"}, {"identifier": "D", "content": "24$$\\Omega$$"}] | ["C"] | null | <img src="https://app-content.cdn.examgoal.net/fly/@width/image/1lgzn18oy/d537e0c0-673b-42f0-b01e-a329a5566eb3/973e7b10-e542-11ed-8d50-d941312069b0/file-1lgzn18oz.png?format=png" data-orsrc="https://app-content.cdn.examgoal.net/image/1lgzn18oy/d537e0c0-673b-42f0-b01e-a329a5566eb3/973e7b10-e542-11ed-8d50-d941312069b0/fi... | mcq | jee-main-2023-online-10th-april-morning-shift | 9,703 |
1lgyfhpni | physics | current-electricity | combination-of-resistances | <p>10 resistors each of resistance 10 $$\Omega$$ can be connected in such as to get maximum and minimum equivalent resistance. The ratio of maximum and minimum equivalent resistance will be ___________.</p> | [] | null | 100 | <p>When resistors are connected in series, the equivalent resistance is the sum of individual resistances. Therefore, the maximum equivalent resistance will be when all 10 resistors are connected in series, giving a total resistance of 100 $$\Omega$$. </p>
<p>When resistors are connected in parallel, the reciprocal of ... | integer | jee-main-2023-online-10th-april-morning-shift | 9,704 |
1lgyqmx5w | physics | current-electricity | combination-of-resistances | <p>The equivalent resistance between A and B as shown in figure is:</p>
<p><img src="data:image/png;base64,UklGRggUAABXRUJQVlA4IPwTAADQbwCdASoAA5YAPm00lkgkIyIhJNMqyIANiWlu62f4/cJ45l/I+Y/732x/6H+0+PfjN9ce2nroZG+q/Uv+TfeP8v65f6X/b+DfAC/Lv6d/lf7Pvz84HqC+6n1z/feGbqU+4WoB/Lf7N/x/Wf/g+D79w9QT9UesB/gf/PzGfVfsP/mr2MvSbKfQA5tB4... | [{"identifier": "A", "content": "$$30 ~\\mathrm{k} \\Omega$$"}, {"identifier": "B", "content": "$$20 ~\\mathrm{k} \\Omega$$"}, {"identifier": "C", "content": "$$5 ~\\mathrm{k} \\Omega$$"}, {"identifier": "D", "content": "$$10 ~\\mathrm{k} \\Omega$$"}] | ["C"] | null | <img src="https://app-content.cdn.examgoal.net/fly/@width/image/6y3zli1ljho9yho/ccf9095a-05e0-467b-adc6-ec0e21a76c80/fd38f1c0-16c5-11ee-84dd-7526dde12945/file-6y3zli1ljho9yhp.png?format=png" data-orsrc="https://app-content.cdn.examgoal.net/image/6y3zli1ljho9yho/ccf9095a-05e0-467b-adc6-ec0e21a76c80/fd38f1c0-16c5-11ee-84... | mcq | jee-main-2023-online-8th-april-evening-shift | 9,705 |
jaoe38c1lsc3x2ws | physics | current-electricity | combination-of-resistances | <p>A wire of resistance $$\mathrm{R}$$ and length $$\mathrm{L}$$ is cut into 5 equal parts. If these parts are joined parallely, then resultant resistance will be :</p> | [{"identifier": "A", "content": "$$\\frac{1}{25} \\mathrm{R}$$\n"}, {"identifier": "B", "content": "$$\\frac{1}{5} R$$"}, {"identifier": "C", "content": "25 R"}, {"identifier": "D", "content": "5 R"}] | ["A"] | null | <p>Resistance of each part $$=\frac{R}{5}$$</p>
<p>Total resistance $$=\frac{1}{5} \times \frac{\mathrm{R}}{5}=\frac{\mathrm{R}}{25}$$</p> | mcq | jee-main-2024-online-27th-january-morning-shift | 9,706 |
jaoe38c1lse6x19d | physics | current-electricity | combination-of-resistances | <p>Equivalent resistance of the following network is __________ $$\Omega$$.</p>
<p><img src="data:image/png;base64,UklGRg4LAABXRUJQVlA4IAILAAAwiACdASoAA+sAP4G81mK2MCwmI9Nq0sAwCWlu8os7/QV3njbuegLQWzc7S/PzpZxAGfX99a0mPJf/w7BhIcEdCbDkrPn0XUA3iaZ3R2kB2uZrv/YSibviR0lrxE/dDB5Td0iLeZrv/jfnukGbeZoF0rcCN//G31wLNGACIE8/aPUDyMJ+u... | [] | null | 1 | <p>$$6\Omega$$ is short circuit</p>
<p><img src="https://app-content.cdn.examgoal.net/fly/@width/image/6y3zli1lslukerg/e4489db0-ea2d-4d06-84c3-c557e61b105d/abaa7fc0-cb3f-11ee-ad47-a16d1086e690/file-6y3zli1lslukerh.png?format=png" data-orsrc="https://app-content.cdn.examgoal.net/image/6y3zli1lslukerg/e4489db0-ea2d-4d06-... | integer | jee-main-2024-online-31st-january-morning-shift | 9,707 |
1lsgdlwra | physics | current-electricity | combination-of-resistances | <p>A potential divider circuit is shown in figure. The output voltage V$$_0$$ is :</p>
<p><img src="data:image/png;base64,UklGRi4LAABXRUJQVlA4ICILAACwggCdASoAAygBP4G+1mW2LywnIhF5wsAwCWlu4W2j0mNwvH5w/239i7s9cMy1y//YL2d/xfhQf+n1ZH13w7Xbjt8qk8b/+9/yJ52Z9CmAd5v7h2Z77vG1cOAUOBs3OJhNzzf3Dsz6FMA7yzsMnfrL0QJO/WXogSbPx9ZzAO839w... | [{"identifier": "A", "content": "2 mV"}, {"identifier": "B", "content": "4 V"}, {"identifier": "C", "content": "0.5 V"}, {"identifier": "D", "content": "12 mV"}] | ["C"] | null | <p>$$\begin{aligned}
& R_{e q}=4000 \Omega \\
& i=\frac{4}{4000}=\frac{1}{1000} \mathrm{~A} \\
& V_0=i . R=\frac{1}{1000} \times 500=0.5 \mathrm{~V}
\end{aligned}$$</p> | mcq | jee-main-2024-online-30th-january-morning-shift | 9,708 |
luxwermh | physics | current-electricity | combination-of-resistances | <p>The effective resistance between $$A$$ and $$B$$, if resistance of each resistor is $$R$$, will be :</p>
<p><img src="data:image/png;base64,UklGRs4NAABXRUJQVlA4IMINAACwrwCdASoAA4EBP4G+2GW2LysnIXGJSsAwCWlu4W8CzmNwvH6UtJ7RX+s79ZfmAD72+ckX4kcz2me0z2me0z2lu7cNFQQR55Z1z2me0z2me0z2memKXj3DFLx7hil49wQFg5UR1heb9W0XZ4iQJexDN... | [{"identifier": "A", "content": "$$\\frac{8 R}{3}$$\n"}, {"identifier": "B", "content": "$$\\frac{4 R}{3}$$\n"}, {"identifier": "C", "content": "$$\\frac{2}{3} R$$\n"}, {"identifier": "D", "content": "$$\\frac{5 R}{3}$$"}] | ["A"] | null | <p>From symmetry we can remove two middle resistance.</p>
<p>New circuit is</p>
<img src="https://app-content.cdn.examgoal.net/fly/@width/image/6y3zli1lwfxiqk1/98b69776-98c1-48d2-ba39-f535f8ab5546/622a3610-172f-11ef-905e-4bbe7c423b86/file-6y3zli1lwfxiqk2.png?format=png" data-orsrc="https://app-content.cdn.examgoal.net... | mcq | jee-main-2024-online-9th-april-evening-shift | 9,709 |
luyitafd | physics | current-electricity | combination-of-resistances | <p>The equivalent resistance between A and B is :</p>
<p><img src="data:image/png;base64,UklGRvQXAABXRUJQVlA4IOgXAACwJwGdASoAA48CP4HA2mQ2Ma0mopK5isAwCWlu4W5RomNwvV54/3ml5/3vtZXx/k+8V22/7j9n//56N/0vhK//P1RoYzhrzt5i3/Pq59/NUh6Kr/99g/30JrPJIJQRkgA36Ii4diL8l/Z5JH7PJI/Z5JCVBD27gaphMPZes/e1qLtVBD8GdrUXaqCH4M7Wou1UEPynQ+9okVV... | [{"identifier": "A", "content": "18 $$\\Omega$$"}, {"identifier": "B", "content": "27 $$\\Omega$$"}, {"identifier": "C", "content": "19 $$\\Omega$$"}, {"identifier": "D", "content": "25 $$\\Omega$$"}] | ["C"] | null | <p>Redrawing the circuit</p>
<p><img src="https://app-content.cdn.examgoal.net/fly/@width/image/1lw3j83cy/6fe3e484-236f-4be6-9602-0970d0afcba1/128dae20-105e-11ef-9330-f7b57aaea8e9/file-1lw3j83cz.png?format=png" data-orsrc="https://app-content.cdn.examgoal.net/image/1lw3j83cy/6fe3e484-236f-4be6-9602-0970d0afcba1/128dae2... | mcq | jee-main-2024-online-9th-april-morning-shift | 9,710 |
lv7v4rh2 | physics | current-electricity | combination-of-resistances | <p>In the given figure $$\mathrm{R}_1=10 \Omega, \mathrm{R}_2=8 \Omega, \mathrm{R}_3=4 \Omega$$ and $$\mathrm{R}_4=8 \Omega$$. Battery is ideal with emf $$12 \mathrm{~V}$$. Equivalent resistant of the circuit and current supplied by battery are respectively :</p>
<p><img src="data:image/png;base64,UklGRjYIAABXRUJQVlA4I... | [{"identifier": "A", "content": "$$12 \\Omega$$ and $$11.4 \\mathrm{~A}$$\n"}, {"identifier": "B", "content": "$$10.5 \\Omega$$ and $$1.14 \\mathrm{~A}$$\n"}, {"identifier": "C", "content": "$$10.5 \\Omega$$ and $$1 \\mathrm{~A}$$\n"}, {"identifier": "D", "content": "$$12 \\Omega$$ and $$1 \\mathrm{~A}$$"}] | ["D"] | null | <p>$$\begin{aligned}
R_{\mathrm{eq}}= & 12 \Omega \\
\text { and, } I & =\frac{E}{R_{\mathrm{eq}}} \\
& =\frac{12}{12} \\
& =1 \mathrm{~A}
\end{aligned}$$</p> | mcq | jee-main-2024-online-5th-april-morning-shift | 9,712 |
lv9s25l3 | physics | current-electricity | combination-of-resistances | <p>A wire of resistance $$20 \Omega$$ is divided into 10 equal parts, resulting pairs. A combination of two parts are connected in parallel and so on. Now resulting pairs of parallel combination are connected in series. The equivalent resistance of final combination is _________ $$\Omega$$.</p> | [] | null | 5 | <p>Let's start by understanding the process of dividing the wire and recombining its parts to form the final configuration. Initially, we have a wire with a resistance of $$20 \Omega$$. This wire is divided into 10 equal parts, each part then has a resistance of:
<p>$$\frac{20 \Omega}{10} = 2 \Omega$$</p>
<p>Since ea... | integer | jee-main-2024-online-5th-april-evening-shift | 9,713 |
OC1Wl3iCwlWoYzF3 | physics | current-electricity | electric-cell-or-battery-and-combination-of-batteries | The nagative $$Zn$$ pole of a Daniell cell, sending a constant current through a circuit, decreases in mass by $$0.13g$$ in $$30$$ minutes. If the electrochemical equivalent of $$Zn$$ and $$Cu$$ are $$32.5$$ and $$31.5$$ respectively, the increase in the mass of the positive $$Cu$$ pole in this time is | [{"identifier": "A", "content": "$$0.180$$ $$g$$ "}, {"identifier": "B", "content": "$$0.141$$ $$g$$ "}, {"identifier": "C", "content": "$$0.126$$ $$g$$ "}, {"identifier": "D", "content": "$$0.242$$ $$g$$ "}] | ["C"] | null | According to Faraday's first law of electrolysis $$m = z \times q$$
<br><br>For same $$q,$$ $$\,\,\,\,\,\,\,\,\,$$ $$m \propto Z$$
<br><br> $$\therefore$$ $${{{m_{Cn}}} \over {{m_{Zn}}}} = {{{Z_{Cu}}} \over {{Z_{Zn}}}}$$
<br><br>$$ \Rightarrow {m_{Cu}} = {{{Z_{Cu}}} \over {{Z_{Zn}}}} \times {m_{Zn}}$$
<br><br>$$ = {{31... | mcq | aieee-2003 | 9,715 |
vaUIfYmyrtMwe3vvoRfbd | physics | current-electricity | electric-cell-or-battery-and-combination-of-batteries | In the circuit shown, the potential difference between A and B is :
<br/><br/><img src="data:image/png;base64,UklGRv4PAABXRUJQVlA4IPIPAADwoACdASoAA1UBP4HA2GU2MCynIfS5osAwCWlu4XEUDmNwvH5v/x3ct/v+YzlweAv6nwN/d/EIyw68Xt/MIvv8J9NJPNf+vg7iSsX6Ii4UmdF+iIuFJnRfoiLhSZ0X6IimcvdaGEffvk5e6QUWGzsTzYhXdHWPmb5PUcsyDtbXVU3um8S0Hfvk5... | [{"identifier": "A", "content": "6 V"}, {"identifier": "B", "content": "3 V"}, {"identifier": "C", "content": "2 V"}, {"identifier": "D", "content": "1 V"}] | ["C"] | null | Potential difference across AB will be equal to battery equivalent across CD
<br><br>V<sub>AB</sub> $$=$$ V<sub>CD</sub> $$=$$ $${{{{{E_1}} \over {{r_1}}} + {{{E_2}} \over {{r_2}}} + {{{E_3}} \over {{r_3}}}} \over {{1 \over {{r_1}}} + {1 \over {{r_2}}} + {1 \over {{r_3}}}}} = {{{1 \over 1} + {2 \over 1} + {3 \over 1}}... | mcq | jee-main-2019-online-11th-january-evening-slot | 9,716 |
TsnUpedtI8smaKhTfH7k9k2k5hi53ya | physics | current-electricity | electric-cell-or-battery-and-combination-of-batteries | The series combination of two batteries, both
of the same emf 10 V, but different internal
resistance of 20$$\Omega $$ and 5$$\Omega $$, is connected to the
parallel combination of two resistors 30$$\Omega $$ and
R $$\Omega $$. The voltage difference across the battery
of internal resistance 20$$\Omega $$ is zero, the ... | [] | null | 30 | <img src="https://res.cloudinary.com/dckxllbjy/image/upload/v1734267597/exam_images/zcqqat174duzg8hy57t5.webp" style="max-width: 100%;height: auto;display: block;margin: 0 auto;" loading="lazy" alt="JEE Main 2020 (Online) 8th January Evening Slot Physics - Current Electricity Question 212 English Explanation">
<br><br>... | integer | jee-main-2020-online-8th-january-evening-slot | 9,718 |
Q34clvSr68zMRvgOr01klrhi7ds | physics | current-electricity | electric-cell-or-battery-and-combination-of-batteries | A cell E<sub>1</sub> of emf 6V and internal resistance 2$$\Omega$$ is connected with another cell E<sub>2</sub> of emf 4V and internal resistance 8$$\Omega$$ (as shown in the figure). The potential difference across points X and Y is :<br/><br/>
<img src="data:image/png;base64,UklGRvIIAABXRUJQVlA4IOYIAABwmQCdASoAA68BP4... | [{"identifier": "A", "content": "10.0 V"}, {"identifier": "B", "content": "2.0 V"}, {"identifier": "C", "content": "5.6 V"}, {"identifier": "D", "content": "3.6 V"}] | ["C"] | null | The circuit can be shown as below<br><br><img src="https://app-content.cdn.examgoal.net/fly/@width/image/1kxemxwjv/abf9ed61-3b59-475a-bf8c-6324b7a2f67e/a899d6a0-618d-11ec-b27d-5f9767b4f07e/file-1kxemxwjw.png?format=png" data-orsrc="https://app-content.cdn.examgoal.net/image/1kxemxwjv/abf9ed61-3b59-475a-bf8c-6324b7a2f67... | mcq | jee-main-2021-online-24th-february-morning-slot | 9,719 |
l7KivpauqXUjtsH3gl1kltjud4z | physics | current-electricity | electric-cell-or-battery-and-combination-of-batteries | In an electrical circuit, a battery is connected to pass 20C of charge through it in a certain given time. The potential difference between two plates of the battery is maintained at 15V. The workdone by the battery is __________J. | [] | null | 300 | <p>Given, charge passing through circuit, q = 20 C</p>
<p>Potential difference between two plates,</p>
<p>V = 15 V</p>
<p>Let W be the amount of work done by battery.</p>
<p>$$\therefore$$ W = qV = 20 $$\times$$ 15 = 300 J</p> | integer | jee-main-2021-online-26th-february-morning-slot | 9,720 |
xpmk7nA6SeBI6PwBix1kmkajtpz | physics | current-electricity | electric-cell-or-battery-and-combination-of-batteries | Two cells of emf 2E and E with internal resistance r<sub>1</sub> and r<sub>2</sub> respectively are connected in series to an external resistor R (see figure). The value of R, at which the potential difference across the terminals of the first cell becomes zero is <br/><br/><img src="data:image/png;base64,UklGRtYDAABXR... | [{"identifier": "A", "content": "r<sub>1</sub> $$-$$ r<sub>2</sub>"}, {"identifier": "B", "content": "$${{{r_1}} \\over 2} - {r_2}$$"}, {"identifier": "C", "content": "$${{{r_1}} \\over 2} + {r_2}$$"}, {"identifier": "D", "content": "r<sub>1</sub> + r<sub>2</sub>"}] | ["B"] | null | <img src="https://res.cloudinary.com/dckxllbjy/image/upload/v1734267275/exam_images/cgnasf2aieoeideeecfg.webp" style="max-width: 100%;height: auto;display: block;margin: 0 auto;" loading="lazy" alt="JEE Main 2021 (Online) 17th March Evening Shift Physics - Current Electricity Question 181 English Explanation 1"><br><br... | mcq | jee-main-2021-online-17th-march-evening-shift | 9,721 |
1l54vh8us | physics | current-electricity | electric-cell-or-battery-and-combination-of-batteries | <p>The combination of two identical cells, whether connected in series or parallel combination provides the same current through an external resistance of 2$$\Omega$$. The value of internal resistance of each cell is</p> | [{"identifier": "A", "content": "2$$\\Omega$$"}, {"identifier": "B", "content": "4$$\\Omega$$"}, {"identifier": "C", "content": "6$$\\Omega$$"}, {"identifier": "D", "content": "8$$\\Omega$$"}] | ["A"] | null | <p><img src="https://app-content.cdn.examgoal.net/fly/@width/image/1l5gh8rty/9f7be829-74c4-4a2a-91bd-244864fc7747/ac694860-00f2-11ed-ba34-71a54c393c2b/file-1l5gh8rtz.png?format=png" data-orsrc="https://app-content.cdn.examgoal.net/image/1l5gh8rty/9f7be829-74c4-4a2a-91bd-244864fc7747/ac694860-00f2-11ed-ba34-71a54c393c2b... | mcq | jee-main-2022-online-29th-june-evening-shift | 9,722 |
1ldpne5ia | physics | current-electricity | electric-cell-or-battery-and-combination-of-batteries | <p>Two identical cells, when connected either in parallel or in series gives same current in an external resistance $$5 ~\Omega$$. The internal resistance of each cell will be ___________ $$\Omega$$.</p> | [] | null | 5 | <img src="https://app-content.cdn.examgoal.net/fly/@width/image/1leh3iv36/459bc693-e3a2-4716-af92-d39b71f2d6f6/c04e7200-b377-11ed-aaca-cb4b36b68d7d/file-1leh3iv4x.png?format=png" data-orsrc="https://app-content.cdn.examgoal.net/image/1leh3iv36/459bc693-e3a2-4716-af92-d39b71f2d6f6/c04e7200-b377-11ed-aaca-cb4b36b68d7d/fi... | integer | jee-main-2023-online-31st-january-morning-shift | 9,725 |
1ldtztpyg | physics | current-electricity | electric-cell-or-battery-and-combination-of-batteries | <p>Two cells are connected between points A and B as shown. Cell 1 has emf of 12 V and internal resistance of 3$$\Omega$$. Cell 2 has emf of 6V and internal resistance of 6$$\Omega$$. An external resistor R of 4$$\Omega$$ is connected across A and B. The current flowing through R will be ____________ A.</p>
<p><img src... | [] | null | 1 | <img src="https://app-content.cdn.examgoal.net/fly/@width/image/1ledm66ki/e55572f1-2340-4b35-b92c-454a6678a17d/8a79da20-b18d-11ed-a682-13f364283dca/file-1ledm66kj.png?format=png" data-orsrc="https://app-content.cdn.examgoal.net/image/1ledm66ki/e55572f1-2340-4b35-b92c-454a6678a17d/8a79da20-b18d-11ed-a682-13f364283dca/fi... | integer | jee-main-2023-online-25th-january-evening-shift | 9,726 |
lv5gt53y | physics | current-electricity | electric-cell-or-battery-and-combination-of-batteries | <p>In the given circuit, the terminal potential difference of the cell is :</p>
<p><img src="data:image/png;base64,UklGRmIKAABXRUJQVlA4IFYKAABwnACdASoAA5QBP4HA2mU2MTqnIRLZo1AwCWlu+F8UopARbuuqPX69f631rGGnQHavq/+E4+b5Uxf5tCJRAJ2U4pKcUlOKSnFJTikpxSU4pKcUlIE5pRbB4JTZgCQMQG90ji3ukcW90ji3sr9LIZHFvdI4t7pHFvdI4tIhIaaKnxIu7vui0... | [{"identifier": "A", "content": "3 V"}, {"identifier": "B", "content": "4 V"}, {"identifier": "C", "content": "2 V"}, {"identifier": "D", "content": "1.5 V"}] | ["C"] | null | <p><img src="https://app-content.cdn.examgoal.net/fly/@width/image/1lw8znu3l/378509fe-1a68-4a65-998e-2fa351a1d4e1/45a8d200-135e-11ef-a2b1-a5535752b4da/file-1lw8znu3m.png?format=png" data-orsrc="https://app-content.cdn.examgoal.net/image/1lw8znu3l/378509fe-1a68-4a65-998e-2fa351a1d4e1/45a8d200-135e-11ef-a2b1-a5535752b4da... | mcq | jee-main-2024-online-8th-april-morning-shift | 9,727 |
lZRfiw1IFBLDNUDX | physics | current-electricity | electric-current,-current-density-and-drift-velocity | Consider a block of conducting material of resistivity $$'\rho '$$ shown in the figure. Current $$'I'$$ enters at $$'A'$$ and leaves from $$'D'$$. We apply superposition principle to find voltage $$'\Delta V'$$ developed between $$'B'$$ and $$'C'$$. The calculation is done in the following steps:
<br/>(i) Take current... | [{"identifier": "A", "content": "$${{\\rho I} \\over {\\pi a}} - {{\\rho I} \\over {\\pi \\left( {a + b} \\right)}}$$ "}, {"identifier": "B", "content": "$${{\\rho I} \\over a} - {{\\rho I} \\over {\\left( {a + b} \\right)}}$$ "}, {"identifier": "C", "content": "$${{\\rho I} \\over {2\\pi a}} - {{\\rho I} \\over {2\\pi... | ["A"] | null | Let $$j$$ be the current density.
<br><br>Then $$j \times 2\pi {r^2} = I \Rightarrow j = {I \over {2\pi {r^2}}}$$
<br><br>$$\therefore$$ $$E = \rho j = {{\rho I} \over {2\pi {r^2}}}$$
<br><br>Now, $$\Delta V{'_{BC}} = $$ $$ - \int\limits_{a + b}^a {\overrightarrow E .\,\overrightarrow {dr} } $$ $$ = - \int\limits_{a +... | mcq | aieee-2008 | 9,729 |
0pfaa66idpGct060y36tc | physics | current-electricity | electric-current,-current-density-and-drift-velocity | A copper rod of cross-sectional area A carries a uniform current I through it. At temperature T, if the volume charge density of the rod is $$\rho $$, how long will the changes take to travel a distance d ? | [{"identifier": "A", "content": "$${{2\\rho \\,d\\,A} \\over {\\rm I}}$$"}, {"identifier": "B", "content": "$${{2\\rho \\,d\\,A} \\over {{\\rm I}\\,T}}$$"}, {"identifier": "C", "content": "$${{\\rho \\,d\\,A} \\over {{\\rm I}\\,}}$$"}, {"identifier": "D", "content": "$${{\\rho \\,d\\,A} \\over {{\\rm I}\\,T}}$$"}] | ["C"] | null | <p>Given : Volume charge density of rod = $$\rho$$.</p>
<p>We know that current $$I = neA{v_d}$$; where n is number of electrons, e is electronic charge, A is area, v<sub>d</sub> is drift velocity</p>
<p><img src="https://app-content.cdn.examgoal.net/fly/@width/image/1l32mjai6/b190ee43-aa8c-418c-ba9e-86a1ff895f27/f6b92... | mcq | jee-main-2018-online-15th-april-evening-slot | 9,730 |
KFdEQ3srMBl8wIzd3GdEJ | physics | current-electricity | electric-current,-current-density-and-drift-velocity | Drift speed of electrons, when 1.5 A of current flows in a copper wire of cross section 5 mm<sup>2</sup>, is $$\upsilon $$. If the electron density in copper is 9 $$ \times $$ 10<sup>28</sup>/m<sup>3</sup> the value of $$\upsilon $$. in mm/s is close to (Take charge of electron to be = 1.6 $$ \times $$ 10<sup>$$-$$19</... | [{"identifier": "A", "content": "0.02"}, {"identifier": "B", "content": "3"}, {"identifier": "C", "content": "2"}, {"identifier": "D", "content": "0.2"}] | ["A"] | null | We know,
<br><br>I = neAV<sub>d</sub>
<br><br>$$ \therefore $$ V<sub>d</sub> = $${{\rm I} \over {neA}}$$
<br><br>= $${{1.5} \over {9 \times {{10}^{28}} \times 1.6{ \times ^{ - 19}} \times 5 \times {{10}^{ - 6}}}}$$
<br><br>= 0.02 m/s | mcq | jee-main-2019-online-9th-january-morning-slot | 9,731 |
tGajPSqxeHTZMhCeKY1klrosthm | physics | current-electricity | electric-current,-current-density-and-drift-velocity | A cylindrical wire of radius 0.5 mm and conductivity 5 $$\times$$ 10<sup>7</sup> S/m is subjected to an electric field of 10 mV/m. The expected value of current in the wire will be x<sup>3</sup>$$\pi$$ mA. The value of x is _________. | [] | null | 5 | We know that current density,<br><br>J = $$\sigma$$E<br><br>$$ \Rightarrow $$ J = 5 $$\times$$ 10<sup>7</sup> $$\times$$ 10 $$\times$$ 10<sup>$$-$$3</sup><br><br>$$ \Rightarrow $$ J = 50 $$\times$$ 10<sup>4</sup> A/m<sup>2</sup><br><br>Current flowing;<br><br>I = J $$\times$$ $$\pi$$R<sup>2</sup><br><br>I = 50 $$\times... | integer | jee-main-2021-online-24th-february-evening-slot | 9,733 |
80wYG2HdaixLuTwhLh1kmj3riu6 | physics | current-electricity | electric-current,-current-density-and-drift-velocity | A current of 10A exists in a wire of cross-sectional area of 5 mm<sup>2</sup> with a drift velocity of 2 $$\times$$ 10<sup>$$-$$3</sup> ms<sup>$$-$$1</sup>. The number of free electrons in each cubic meter of the wire is ___________. | [{"identifier": "A", "content": "625 $$\\times$$ 10<sup>25</sup>"}, {"identifier": "B", "content": "1 $$\\times$$ 10<sup>23</sup>"}, {"identifier": "C", "content": "2 $$\\times$$ 10<sup>25</sup>"}, {"identifier": "D", "content": "2 $$\\times$$ 10<sup>6</sup>"}] | ["A"] | null | $$I = neA{V_d}$$<br><br>$$n = {I \over {eA{V_d}}}$$<br><br>$$ = {{10} \over {1.6 \times {{10}^{ - 9}} \times 5 \times {{10}^{ - 6}} \times 2 \times {{10}^{ - 3}}}}$$<br><br>$$ = {{{{10}^{25}}} \over {16}} = 6.25 \times {10^{27}} = 625 \times {10^{25}}$$ | mcq | jee-main-2021-online-17th-march-morning-shift | 9,734 |
xpWIIvBgrgxysqhEjq1krpli03n | physics | current-electricity | electric-current,-current-density-and-drift-velocity | A current of 5 A is passing through a non-linear magnesium wire of cross-section 0.04 m<sup>2</sup>. At every point the direction of current density is at an angle of 60$$^\circ$$ with the unit vector of area of cross-section. The magnitude of electric field at every point of the conductor is :<br/><br/>(Resistivity of... | [{"identifier": "A", "content": "11 $$\\times$$ 10<sup>$$-$$5</sup> V/m"}, {"identifier": "B", "content": "11 $$\\times$$ 10<sup>$$-$$3</sup> V/m"}, {"identifier": "C", "content": "11 $$\\times$$ 10<sup>$$-$$7</sup> V/m"}, {"identifier": "D", "content": "11 $$\\times$$ 10<sup>$$-$$2</sup> V/m"}] | ["A"] | null | Given, current, I = 5A<br/><br/>Area of cross-section of wire, A = 0.04 m<sup>2</sup><br/><br/>We know that, $$J = {I \over A}$$<br/><br/>$$ \Rightarrow I = JA$$<br/><br/>or $$I = J\,.\,A$$ or $$I = JA\cos \theta $$<br/><br/>where, J = current density.<br/><br/>$$ \Rightarrow 5 = J\left( {{4 \over {100}}} \right) \time... | mcq | jee-main-2021-online-20th-july-morning-shift | 9,735 |
1l56wjhws | physics | current-electricity | electric-current,-current-density-and-drift-velocity | <p>The current density in a cylindrical wire of radius r = 4.0 mm is 1.0 $$\times$$ 10<sup>6</sup> A/m<sup>2</sup>. The current through the outer portion of the wire between radial distances $${r \over 2}$$ and r is x$$\pi$$ A; where x is __________.</p> | [] | null | 12 | <p>$$i = A \times j$$</p>
<p>$$ = \pi \left( {{R^2} - {{{R^2}} \over 4}} \right)j$$</p>
<p>$$ = {{3\pi {R^2}} \over 4} \times j$$</p>
<p>$$ = {{3\pi \times {{(4 \times {{10}^{ - 3}})}^2}} \over 4} \times 1.0 \times {10^6}$$</p>
<p>$$ = 12\,\pi $$</p> | integer | jee-main-2022-online-27th-june-evening-shift | 9,736 |
1l57qso1o | physics | current-electricity | electric-current,-current-density-and-drift-velocity | <p>The current density in a cylindrical wire of radius 4 mm is 4 $$\times$$ 10<sup>6</sup> Am<sup>$$-$$2</sup>. The current through the outer portion of the wire between radial distances $${R \over 2}$$ and R is ____________ $$\pi$$ A.</p> | [] | null | 48 | <p>$$i = A \times j$$</p>
<p>$$ = \pi \left( {{R^2} - {{{R^2}} \over 4}} \right)j$$</p>
<p>$$ = {{3\pi {R^2}} \over 4} \times j$$</p>
<p>$$ = {{3\pi \times {{(4 \times {{10}^{ - 3}})}^2}} \over 4} \times 4 \times {10^6}$$</p>
<p>$$ = 48\pi $$</p> | integer | jee-main-2022-online-27th-june-morning-shift | 9,737 |
1l6dxt71y | physics | current-electricity | electric-current,-current-density-and-drift-velocity | <p>Which of the following physical quantities have the same dimensions?</p> | [{"identifier": "A", "content": "Electric displacement $$(\\overrightarrow{\\mathrm{D}})$$ and surface charge density"}, {"identifier": "B", "content": "Displacement current and electric field"}, {"identifier": "C", "content": "Current density and surface charge density"}, {"identifier": "D", "content": "Electric poten... | ["A"] | null | <p>Electric displacement $$(\overrightarrow D ) = {\varepsilon _0}\overrightarrow E $$</p>
<p>$$ \Rightarrow [\overline D ] = [{\varepsilon _0}][\overline E ]$$</p>
<p>$$ = [{M^{ - 1}}{L^{ - 3}}{T^4}{A^2}][{M^1}{L^1}{A^{ - 1}}{T^{ - 3}}]$$</p>
<p>$$[\overline D ] = [{L^{ - 2}}{T^1}{A^1}]$$</p>
<p>[Surface charge densit... | mcq | jee-main-2022-online-25th-july-morning-shift | 9,738 |
1l6jj9ljr | physics | current-electricity | electric-current,-current-density-and-drift-velocity | <p>A $$1 \mathrm{~m}$$ long copper wire carries a current of $$1 \mathrm{~A}$$. If the cross section of the wire is $$2.0 \mathrm{~mm}^{2}$$ and the resistivity of copper is $$1.7 \times 10^{-8}\, \Omega \mathrm{m}$$, the force experienced by moving electron in the wire is ____________ $$\times 10^{-23} \mathrm{~N}$$.<... | [] | null | 136 | <p>$$I = ne{v_d}A$$</p>
<p>$$J = {E \over \rho }$$</p>
<p>$$F = eE = {{1.7 \times 1.6 \times {{10}^{ - 19}} \times {{10}^{ - 8}}} \over {2 \times {{10}^{ - 6}}}}$$</p>
<p>$$ = 136 \times {10^{ - 23}}$$ N</p> | integer | jee-main-2022-online-27th-july-morning-shift | 9,739 |
1l6kn6rwa | physics | current-electricity | electric-current,-current-density-and-drift-velocity | <p>(A) The drift velocity of electrons decreases with the increase in the temperature of conductor.</p>
<p>(B) The drift velocity is inversely proportional to the area of cross-section of given conductor.</p>
<p>(C) The drift velocity does not depend on the applied potential difference to the conductor.</p>
<p>(D) The ... | [{"identifier": "A", "content": "(A) and (B) only"}, {"identifier": "B", "content": "(A) and (D) only"}, {"identifier": "C", "content": "(B) and (E) only"}, {"identifier": "D", "content": "(B) and (C) only"}] | ["B"] | null | <p>We know, Resistivity $\rho=\frac{m}{n e^2 \tau}$
<br/><br/> Where $\tau$ is relaxation time As temperature $\uparrow, \tau \downarrow, \rho \uparrow, \mathrm{R} \uparrow, \mathrm{i} \downarrow, \mathrm{v}_{\mathrm{d}} \downarrow$ as $i=$ ne $\mathrm{A} v_{\mathrm{d}}$
<br/><br/>Statement (A) is correct and hence st... | mcq | jee-main-2022-online-27th-july-evening-shift | 9,740 |
1ldpk8tj4 | physics | current-electricity | electric-current,-current-density-and-drift-velocity | <p>The drift velocity of electrons for a conductor connected in an electrical circuit is $$\mathrm{V}_{\mathrm{d}}$$. The conductor in now replaced by another conductor with same material and same length but double the area of cross section. The applied voltage remains same. The new drift velocity of electrons will be<... | [{"identifier": "A", "content": "$$\\frac{V_{d}}{4}$$"}, {"identifier": "B", "content": "$$\\mathrm{V}_{\\mathrm{d}}$$"}, {"identifier": "C", "content": "$$2 \\mathrm{~V}_{\\mathrm{d}}$$"}, {"identifier": "D", "content": "$$\\frac{V_{d}}{2}$$"}] | ["B"] | null | Drift velocity of electron, $V_d=\frac{-e E \tau}{m}$
<br/><br/>As $E=\frac{V}{l}$
<br/><br/>We can write, $V_d=\frac{-e V\tau}{m l}$
<br/><br/>where, $l=$ length of conductor,
<br/><br/>$V$ is applied voltage
<br/><br/>As drift velocity does not depends upon area, so it will remain same, even after changing area of co... | mcq | jee-main-2023-online-31st-january-morning-shift | 9,741 |
1ldr17hf1 | physics | current-electricity | electric-current,-current-density-and-drift-velocity | <p>The charge flowing in a conductor changes with time as $$\mathrm{Q}(\mathrm{t})=\alpha \mathrm{t}-\beta \mathrm{t}^{2}+\gamma \mathrm{t}^{3}$$. Where $$\alpha, \beta$$ and $$\gamma$$ are constants. Minimum value of current is :</p> | [{"identifier": "A", "content": "$$\\beta-\\frac{\\alpha^{2}}{3 \\gamma}$$"}, {"identifier": "B", "content": "$$\\alpha-\\frac{3 \\beta^{2}}{\\gamma}$$"}, {"identifier": "C", "content": "$$\\alpha-\\frac{\\beta^{2}}{3 \\gamma}$$"}, {"identifier": "D", "content": "$$\\alpha-\\frac{\\gamma^{2}}{3 \\beta}$$"}] | ["C"] | null | <p>$$Q(t) = \alpha t - \beta {t^2} + \gamma {t^3}$$</p>
<p>$$i(t) = \alpha - 2\beta t + 3\gamma {t^2}$$</p>
<p>$${{di} \over {dt}} = - 2\beta + 6\gamma t = 0$$ (for max/min of i)</p>
<p>at $$t = {\beta \over {3r}}$$ (i is minimum as i is an upward parabola)</p>
<p>$$i\left( {{\beta \over {3\gamma }}} \right) = \al... | mcq | jee-main-2023-online-30th-january-morning-shift | 9,742 |
lsblnqwx | physics | current-electricity | electric-current,-current-density-and-drift-velocity | The current in a conductor is expressed as $I=3 t^2+4 t^3$, where $I$ is in Ampere and $t$ is in second. The amount of electric charge that flows through a section of the conductor during $t=1 \mathrm{~s}$ to $t=2 \mathrm{~s}$ is __________ C. | [] | null | 22 | <p>To find the amount of electric charge that flows through a section of the conductor, we have to integrate the current over the given time interval. The current $I(t)$ as a function of time $t$ is given by:</p>
$$ I=3t^2+4t^3 $$
<p>The electric charge $Q$ that flows through the conductor from time $t = 1$ s to $t =... | integer | jee-main-2024-online-1st-february-morning-shift | 9,745 |
jaoe38c1lsf1v1sw | physics | current-electricity | electric-current,-current-density-and-drift-velocity | <p>The electric current through a wire varies with time as $$I=I_0+\beta t$$, where $$I_0=20 \mathrm{~A}$$ and $$\beta=3 \mathrm{~A} / \mathrm{s}$$. The amount of electric charge crossed through a section of the wire in $$20 \mathrm{~s}$$ is :</p> | [{"identifier": "A", "content": "80 C"}, {"identifier": "B", "content": "800 C"}, {"identifier": "C", "content": "1000 C"}, {"identifier": "D", "content": "1600 C"}] | ["C"] | null | <p>To calculate the amount of electric charge $Q$ that crosses through a section of the wire over a period of $20$ seconds, given the current varies with time as $I = I_0 + \beta t$, where $I_0 = 20$ A (initial current) and $\beta = 3$ A/s (rate of change of current with time), we use the concept of integration from ca... | mcq | jee-main-2024-online-29th-january-morning-shift | 9,746 |
B6JootYK7CfkeBOL | physics | current-electricity | electric-power-and-heating-effect-of-current | If $${\theta _1},$$ is the inversion temperature, $${\theta _n}$$ is the neutral temperature, $${\theta _c}$$ is the temperature of the cold junction, then | [{"identifier": "A", "content": "$${\\theta _i} + {\\theta _c} = {\\theta _n}$$ "}, {"identifier": "B", "content": "$${\\theta _i} - {\\theta _c} = 2{\\theta _n}$$ "}, {"identifier": "C", "content": "$${{{\\theta _i} + {\\theta _C}} \\over 2} = {\\theta _n}$$ "}, {"identifier": "D", "content": "$${\\theta _c} - {\\thet... | ["C"] | null | $${\theta _n} = {{{\theta _i} + {\theta _c}} \over 2}.$$ | mcq | aieee-2002 | 9,747 |
Ae3bAf5clPJFkbtA | physics | current-electricity | electric-power-and-heating-effect-of-current | If in the circuit, power dissipation is $$150W,$$ then $$R$$ is
<img src="data:image/png;base64,UklGRugLAABXRUJQVlA4INwLAADQWwCdASoxAgIBPm02lkkkIqKhILLpqIANiWlu4XPxG/OH8qf0X8cvBz+9fkz1wHm32p/Gz2jNXH9z/ln9d/1H5b/gT1APaPgF+v/6n/KP5f/t/J0/FXxEgBfUH+8fzD91f7v8UXs3+q/lHqN9X/0P+AD+ZfyP/Ofx/+he83+T/SXzSPGP0Y+Af8z/8X+Sf332T/7... | [{"identifier": "A", "content": "$$2\\,\\Omega $$ "}, {"identifier": "B", "content": "$$6\\,\\Omega $$"}, {"identifier": "C", "content": "$$5\\,\\Omega $$"}, {"identifier": "D", "content": "$$4\\,\\Omega $$"}] | ["B"] | null | The equivalent resistance is $${{\mathop{\rm R}\nolimits} _{eq}} = {{2 \times R} \over {2 + R}}$$
<br><br>$$\therefore$$ Powder dissipation $$P = {{{V^2}} \over {{{\mathop{\rm R}\nolimits} _{eq}}}}$$
<br><br>$$\therefore$$ $$150 = {{15 \times 15} \over {{R_{eq}}}}$$
<br><br>$$\therefore$$ $${{\mathop{\rm R}\nolimits}... | mcq | aieee-2002 | 9,748 |
5M7EROC16wZRTCRZ | physics | current-electricity | electric-power-and-heating-effect-of-current | A wire when connected to $$220$$ $$V$$ mains supply has power dissipation $${P_1}.$$ Now the wire is cut into two equal pieces which are connected in parallel to the same supply. Power dissipation in this case is $${P_2}.$$ Then $${P_2}:{P_1}$$ is | [{"identifier": "A", "content": "$$1$$ "}, {"identifier": "B", "content": "$$4$$ "}, {"identifier": "C", "content": "$$2$$ "}, {"identifier": "D", "content": "$$3$$ "}] | ["B"] | null | <b>Case 1 :</b> $${P_1} = {{{V^2}} \over R}$$
<br><br><img class="question-image" src="https://imagex.cdn.examgoal.net/uKKPmrvAB9zP9OIov/3XAQYM47v2Cp3Do2vEQkn7cwJerbt/pLK0N1xvtov0dMu8TqRAOZ/image.svg" loading="lazy" alt="AIEEE 2002 Physics - Current Electricity Question 330 English Explanation 1">
<br><br><b>Case 2 :<... | mcq | aieee-2002 | 9,749 |
Cy7fSXIy2UPkikqw | physics | current-electricity | electric-power-and-heating-effect-of-current | A $$220$$ volt, $$1000$$ watt bulb is connected across a $$110$$ $$volt$$ mains supply. The power consumed will be | [{"identifier": "A", "content": "$$750$$ watt "}, {"identifier": "B", "content": "$$500$$ watt "}, {"identifier": "C", "content": "$$250$$ watt "}, {"identifier": "D", "content": "$$1000$$ watt "}] | ["C"] | null | We know that $$R = {{V_{rated}^2} \over {{P_{rated}}}} = {{{{\left( {220} \right)}^2}} \over {1000}}$$
<br><br>When this bulb is connected to $$110$$ volt mains supply we get
<br><br>$$P = {{{V^2}} \over R} = {{{{\left( {110} \right)}^2} \times 1000} \over {{{\left( {220} \right)}^2}}} = {{1000} \over 4} = 250W$$ | mcq | aieee-2003 | 9,750 |
n45THVOLm0IPeJTq | physics | current-electricity | electric-power-and-heating-effect-of-current | The electrochemical equivalent of a metal is $${3.35109^{ - 7}}$$ $$kg$$ per Coulomb. The mass of the metal liberated at the cathode when a $$3A$$ current is passed for $$2$$ seconds will be | [{"identifier": "A", "content": "$$6.6 \\times {10^{57}}/kg$$ "}, {"identifier": "B", "content": "$$9.9 \\times {10^{ - 7}}\\,kg$$ "}, {"identifier": "C", "content": "$$19.8 \\times {10^{ - 7}}\\,kg$$ "}, {"identifier": "D", "content": "$$1.1 \\times {10^{ - 7}}\\,kg$$ "}] | ["C"] | null | The mass liberated $$m,$$ electrochemical equivalent of a metal $$Z,$$ are related as $$m = Zit$$
<br><br>$$ \Rightarrow m = 3.3 \times {10^{ - 7}} \times 3 \times 2$$
<br><br>$$ = 19.8 \times {10^{ - 7}}\,kg$$ | mcq | aieee-2004 | 9,751 |
plnK8UfkILcELtWx | physics | current-electricity | electric-power-and-heating-effect-of-current | The thermo $$emf$$ of a thermocouple varies with temperature $$\theta $$ of the hot junction as $$E = a\theta + b{\theta ^2}$$ in volts where the ratio $$a/b$$ is $${700^ \circ }C.$$ If the cold junction is kept at $${0^ \circ }C,$$ then the neutral temperature is | [{"identifier": "A", "content": "$${1400^ \\circ }C$$ "}, {"identifier": "B", "content": "$${350^ \\circ }C$$"}, {"identifier": "C", "content": "$${700^ \\circ }C$$"}, {"identifier": "D", "content": "No neutral temperature is possible for this termocouple."}] | ["D"] | null | Neutral temperature is the temperature of a hot junction at which $$E$$ is maximum.
<br><br>$$ \Rightarrow {{dE} \over {d\theta }} = 0$$
<br><br>or $$a + 2b\theta = 0 \Rightarrow \theta = {{ - a} \over {2b}} = - 350$$
<br><br>Neutral temperature can never be negative hence no $$\theta $$ is possible. | mcq | aieee-2004 | 9,752 |
ZiHpAhp6kbYElwTC | physics | current-electricity | electric-power-and-heating-effect-of-current | The resistance of hot tungsten filament is about $$10$$ times the cold resistance. What will be resistance of $$100$$ $$W$$ and $$200$$ $$V$$ lamp when not in use ? | [{"identifier": "A", "content": "$$20\\Omega $$ "}, {"identifier": "B", "content": "$$40\\Omega $$"}, {"identifier": "C", "content": "$$200\\Omega $$"}, {"identifier": "D", "content": "$$400\\Omega $$"}] | ["B"] | null | $$P = Vi = {{{V_2}} \over R}$$
<br><br>$${R_{hot}} = {{{V^2}} \over P} = {{200 \times 200} \over {100}} = 400\Omega $$
<br><br>$${R_{cold}} = {{400} \over {10}} = 40\Omega $$ | mcq | aieee-2005 | 9,754 |
LeIK1aAr1ED4jkSx | physics | current-electricity | electric-power-and-heating-effect-of-current | An electric bulb is rated $$220$$ volt - $$100$$ watt. The power consumed by it when operated on $$110$$ volt will be | [{"identifier": "A", "content": "$$75$$ watt "}, {"identifier": "B", "content": "$$40$$ watt"}, {"identifier": "C", "content": "$$25$$ Watt "}, {"identifier": "D", "content": "$$50$$ Watt"}] | ["C"] | null | The resistance of the bulb is $$R = {{{V^2}} \over P} = {{{{\left( {220} \right)}^2}} \over {100}}$$
<br><br>The power consumed when operated at $$110$$ $$V$$ is
<br><br>$$P = {{{{\left( {110} \right)}^2}} \over {{{\left( {220} \right)}^2}/100}} = {{100} \over 4} = 25\,W$$ | mcq | aieee-2006 | 9,755 |
eDjbNrFk51ERIpfm | physics | current-electricity | electric-power-and-heating-effect-of-current | The resistance of bulb filmanet is $$100\Omega $$ at a temperature of $${100^ \circ }C.$$ If its temperature coefficient of resistance be $$0.005$$ per $$^ \circ C$$, its resistance will become $$200\,\Omega $$ at a temperature of | [{"identifier": "A", "content": "$${300^ \\circ }C$$ "}, {"identifier": "B", "content": "$${400^ \\circ }C$$"}, {"identifier": "C", "content": "$${500^ \\circ }C$$"}, {"identifier": "D", "content": "$${200^ \\circ }C$$"}] | ["B"] | null | $$R{}_1 = {R_0}\left[ {1 + \alpha \times 100} \right] = 100\,\,\,\,\,\,\,\,\,\,\,...\left( 1 \right)$$
<br><br>$${R_2} = {R_0}\left[ {1 + \alpha \times T} \right] = 200\,\,\,\,\,\,\,\,\,\,\,\,\,\,...\left( 2 \right)$$
<br><br>On dividing we get
<br><br>$${{200} \over {100}} = {{1 + \alpha T} \over {1 + 100\alpha }}$$... | mcq | aieee-2006 | 9,756 |
Zz73Qo0XAcyd5G1N | physics | current-electricity | electric-power-and-heating-effect-of-current | The supply voltage to room is $$120V.$$ The resistance of the lead wires is $$6\Omega $$. A $$60$$ $$W$$ bulb is already switched on. What is the decrease of voltage across the bulb, when a $$240$$ $$W$$ heater is switched on in parallel to the bulb? | [{"identifier": "A", "content": "zero "}, {"identifier": "B", "content": "$$2.9$$ Volt"}, {"identifier": "C", "content": "$$13.3$$ Volt"}, {"identifier": "D", "content": "$$10.04$$ Volt "}] | ["D"] | null | <img class="question-image" src="https://imagex.cdn.examgoal.net/O5zR4337zfTSNyDRm/hWmAcYLkn35cX3r5lK4TjhXK06PmG/x0LvodpPTlpqZnvNwCCuq4/image.svg" loading="lazy" alt="JEE Main 2013 (Offline) Physics - Current Electricity Question 295 English Explanation">
<br><br>Power of bulb $$=60W$$ $$\left( {given} \right)$$
<br><b... | mcq | jee-main-2013-offline | 9,760 |
LklwnUiSpSO9Zkmh | physics | current-electricity | electric-power-and-heating-effect-of-current | In a large building, three are $$15$$ bulbs of $$40$$ $$W$$, $$5$$ bulbs of $$100$$ $$W$$, $$5$$ fans of $$80$$ $$W$$ and $$1$$ heater of $$1$$ $$kW.$$ The voltage of electric mains is $$220$$ $$V.$$ The minimum capacity of the main fuse of the building will be: | [{"identifier": "A", "content": "$$8$$ $$A$$ "}, {"identifier": "B", "content": "$$10$$ $$A$$ "}, {"identifier": "C", "content": "$$12$$ $$A$$ "}, {"identifier": "D", "content": "$$14$$ $$A$$ "}] | ["C"] | null | Total power consumed by electrical appliances in the building, $${P_{total}} = 2500W$$
<br><br>Watt $$=$$ Volt $$ \times $$ ampere
<br><br>$$ \Rightarrow 2500 = V \times {\rm I}$$
<br><br>$$ \Rightarrow 2500 = 220$$ $${\rm I}$$
<br><br>$$ \Rightarrow I = {{2500} \over {220}} = 11.36 \approx 12A$$
<br><br>(Minimum capac... | mcq | jee-main-2014-offline | 9,761 |
R4yweZrL7e7p0D9Y16OZk | physics | current-electricity | electric-power-and-heating-effect-of-current | <img src="data:image/png;base64,UklGRiwKAABXRUJQVlA4ICAKAADQuwCdASoAA1ICP4G812a2LiwnoLB5GsAwCWlu+EMIjDtpNlvtio4e7ecTTG69lU//WYO+EXuk64dNybk3JuTcm5Nybk3JuTcm5Nybk3JuTcm5Nybk3Jqia+FT0vSshrMzpXOZtpcOm5Nybk3JuTcm5Nybk3JuTcm5INp+RQbuJo9jC2k4wqP0F5y66VJ1w6bk3JuTcm5Nybk1GggwUQKUP0S0wFiyJ+73JuTcm5Nybk3JuTcm5Nybk3JuR4BBqMoLjdgF... | [{"identifier": "A", "content": "$${1 \\over 4}$$ "}, {"identifier": "B", "content": "$${1 \\over 2}$$ "}, {"identifier": "C", "content": "$${3 \\over 4}$$ "}, {"identifier": "D", "content": "1"}] | ["B"] | null | Here equivalent resistance
<br><br>R<sub>eq</sub> = R + $${{r \times R} \over {r + R}}$$
<br><br>= R + $${{f{R^2}} \over {fR + R}}$$
<br><br>= R + $${{fR} \over {f + 1}}$$
<br><br>= $${{\left( {2f + 1} \right)R} \over {\left( {f + 1} \right)}}$$
<br><br>Circuit current,
<br><br>$${\... | mcq | jee-main-2016-online-9th-april-morning-slot | 9,762 |
0FnGOyrhSQdUbYWKbkYry | physics | current-electricity | electric-power-and-heating-effect-of-current | A constant voltages is applied between two ends of a metallic wire. If the length is halved and the radius of the wire is doubled, the rate of heat developed in the wire will be : | [{"identifier": "A", "content": "Doubled "}, {"identifier": "B", "content": "Halved"}, {"identifier": "C", "content": "Unchanged"}, {"identifier": "D", "content": "Increased 8 times "}] | ["D"] | null | <p>Since rate of heat $$ = {{{V^2}} \over R} \Rightarrow $$ rate of heat $$ \propto {1 \over R}$$, where $$R = {{\rho L} \over A} = {{\rho L} \over {\pi {r^2}}}$$; here r is radius of wire and L is length of wire. Therefore,</p>
<p>$$R \propto {L \over {{r^2}}}$$.</p>
<p>Thus, rate of heat $$ \propto {{{r^2}} \over L}$... | mcq | jee-main-2018-online-15th-april-evening-slot | 9,765 |
QGvTEfImdjpnMoMOsUGMj | physics | current-electricity | electric-power-and-heating-effect-of-current | A 2 W carbon resistor is color coded with green, black, red and brown respectively. The maximum current which can be passed through this resistor is - | [{"identifier": "A", "content": "0.4 mA"}, {"identifier": "B", "content": "20 mA"}, {"identifier": "C", "content": "63 mA"}, {"identifier": "D", "content": "100 mA"}] | ["B"] | null | P = i<sup>2</sup>R.
<br><br>$$ \therefore $$ for i<sub>max</sub>, R must be minimum
<br><br>from color coding R = 50 $$ \times $$ 10<sup>2</sup>$$\Omega $$
<br><br>$$ \therefore $$ i<sub>max</sub> = 20mA | mcq | jee-main-2019-online-10th-january-morning-slot | 9,767 |
YtHzseqCepostZcVqd6l3 | physics | current-electricity | electric-power-and-heating-effect-of-current | A current of 2 mA was passed through an unknown resistor which dissipated a power of 4.4 W. Dissipated power when an ideal power supply of 11 V is connected across it is - | [{"identifier": "A", "content": "11 $$ \\times $$ 10<sup>\u20135</sup> W"}, {"identifier": "B", "content": "11 $$ \\times $$ 10<sup>\u20133</sup> W"}, {"identifier": "C", "content": "11 $$ \\times $$ 10<sup>5</sup> W"}, {"identifier": "D", "content": "11 $$ \\times $$ 10<sup>\u20134</sup> W"}] | ["A"] | null | P = I<sup>2</sup>R
<br><br>4.4 = 4 $$ \times $$ 10<sup>$$-$$6</sup> R
<br><br>R = 1.1 $$ \times $$ 10<sup>6</sup> $$\Omega $$
<br><br>P' = $${{{{11}^2}} \over R}$$ = $${{{{11}^2}} \over {1.1}}$$ $$ \times $$ 10<sup>$$-$$6</sup> = 11 $$ \times $$ 10<sup>$$-$$5</sup> W | mcq | jee-main-2019-online-10th-january-evening-slot | 9,768 |
TDAQw6Br20fMX5WWviih2 | physics | current-electricity | electric-power-and-heating-effect-of-current | Two electric bulbs, rated at (25 W, 220 V) and (100 W, 220 V), are connected in series across a 220 V voltage source. If the 25 W and 100 W bulbs draw powers P<sub>1</sub> and P<sub>2</sub> respectively, then :
| [{"identifier": "A", "content": "P<sub>1</sub> = 4W, P<sub>2</sub> = 16 W"}, {"identifier": "B", "content": "P<sub>1</sub> = 16W, P<sub>2</sub> = 4 W"}, {"identifier": "C", "content": "P<sub>1</sub> = 9W, P<sub>2</sub> = 16 W"}, {"identifier": "D", "content": "P<sub>1</sub> = 16W, P<sub>2</sub> = 9 W"}] | ["B"] | null | $${R_1} = {{{{220}^2}} \over {25}}$$
<br><br>$${R_2} = {{{{220}^2}} \over {100}}$$
<br><br>$$L = {{220} \over {{R_1} + {R_2}}}$$
<br><br>$${P_1} = {i^2}\,{R_1}$$
<br><br>$${P_2} = {i^2}\,\,({R_2}\, = \,4W)$$
<br><br>$$ = {{{{220}^2}} \over {\left( {{{{{220}^2}} \over {25}} + {{{{220}^2}} \over {100}}} \right)}} \times ... | mcq | jee-main-2019-online-12th-january-morning-slot | 9,770 |
JlybRSy5VmrfmBLdret67 | physics | current-electricity | electric-power-and-heating-effect-of-current | A cell of internal resistance r drives current
through an external resistance R. The power
delivered by the cell to the external resistance
will be maximum when :- | [{"identifier": "A", "content": "R = 1000 r"}, {"identifier": "B", "content": "R = r"}, {"identifier": "C", "content": "R = 2r"}, {"identifier": "D", "content": "R = 0.001 r"}] | ["B"] | null | Current i = $${E \over {r + R}}$$<br><br>
Power generated in R<br><br>
P = i<sup>2</sup>R<br><br>
$$P = {{{E^2}R} \over {{{\left( {r + R} \right)}^2}}}$$<br><br>
For maximum power $${{dP} \over {dR}} = 0$$<br><br>
$${E^2}\left[ {{{{{\left( {r + R} \right)}^2} \times 1 - R \times 2(r + R)} \over {{{\left( {r + R} \right... | mcq | jee-main-2019-online-8th-april-evening-slot | 9,771 |
fP2uVywjs5a44fwh6Z3rsa0w2w9jx3lqscb | physics | current-electricity | electric-power-and-heating-effect-of-current | The resistive network shown below is connected to a D.C. source of 16 V. The power consumed by the
network is 4 Watt. The value of R is:
<img src="data:image/png;base64,UklGRjoQAABXRUJQVlA4IC4QAABQXQCdASo2Ad0APm0ylUikIqIhI1Ca+IANiWlu4XExG/OZ8O/zH8efAH+pflD6D/iPy79P/I/+2f9z2sP4D+LfwDrNP57+Kd177F/Hv6p/o/69+0P31/MP7H/Pv6J... | [{"identifier": "A", "content": "16 $$\\Omega $$"}, {"identifier": "B", "content": "1 $$\\Omega $$"}, {"identifier": "C", "content": "8 $$\\Omega $$"}, {"identifier": "D", "content": "6 $$\\Omega $$"}] | ["C"] | null | R<sub>eq</sub> = 2R + R + 4R + R = 8R<br><br>
$$P = {{{v^2}} \over {{R_{eq}}}} \Rightarrow {{16 \times 16} \over {8R}} = 4\,watt$$<br><br>
$${{16 \times 16} \over {4 \times 8}} = R \Rightarrow R = 8\Omega $$ | mcq | jee-main-2019-online-12th-april-morning-slot | 9,772 |
Iq5eDmMxk6JKGrBLncjgy2xukfdqit5p | physics | current-electricity | electric-power-and-heating-effect-of-current | An electrical power line, having a total
resistance of 2 $$\Omega $$, delivers 1 kW at 220 V. The
efficiency of the transmission line is
approximately : | [{"identifier": "A", "content": "85%"}, {"identifier": "B", "content": "96%"}, {"identifier": "C", "content": "72%"}, {"identifier": "D", "content": "91%"}] | ["B"] | null | We know, $$\eta = {{{P_{out}}} \over {\left( {{P_{out}} + {P_{loss}}} \right)}} \times 100$$
<br><br>Given, P= $$vi = {10^3}$$<br><br>$$ \therefore $$ $$i = {{1000} \over {220}}$$ = $${{50} \over {11}}$$ A
<br><br>Power $$loss = {i^2}R = {\left( {{{50} \over {11}}} \right)^2} \times 2$$<br><br>$$ \therefore $$ efficie... | mcq | jee-main-2020-online-5th-september-morning-slot | 9,773 |
uIhcEzFu1YbjYBk0Kvjgy2xukf148qlr | physics | current-electricity | electric-power-and-heating-effect-of-current | Model a torch battery of length $$l$$ to be made up
of a thin cylindrical bar of radius ‘a’ and a
concentric thin cylindrical shell of radius ‘b’
filled in between with an electrolyte of
resistivity $$\rho $$ (see figure). If the battery is
connected to a resistance of value R, the
maximum Joule heating in R will take ... | [{"identifier": "A", "content": "$$R = {{2\\rho } \\over {\\pi l}}\\ln \\left( {{b \\over a}} \\right)$$"}, {"identifier": "B", "content": "$$R = {\\rho \\over {\\pi l}}\\ln \\left( {{b \\over a}} \\right)$$"}, {"identifier": "C", "content": "$$R = {\\rho \\over {2\\pi l}}\\ln \\left( {{b \\over a}} \\right)$$"}, {"i... | ["C"] | null | <img src="https://res.cloudinary.com/dckxllbjy/image/upload/v1734264480/exam_images/zimffftypxaibcryt3l3.webp" style="max-width: 100%;height: auto;display: block;margin: 0 auto;" loading="lazy" alt="JEE Main 2020 (Online) 3rd September Morning Slot Physics - Current Electricity Question 206 English Explanation">
<br><b... | mcq | jee-main-2020-online-3rd-september-morning-slot | 9,774 |
40hnYKxW0rROM846gS7k9k2k5f7hmp6 | physics | current-electricity | electric-power-and-heating-effect-of-current | In a building there are 15 bulbs of 45 W, 15 bulbs of 100 W, 15 small fans of 10 W and 2 heaters
of 1 kW. The voltage of electric main is 220 V. The minimum fuse capacity (rated value) of the
building will be : | [{"identifier": "A", "content": "15 A"}, {"identifier": "B", "content": "20 A"}, {"identifier": "C", "content": "25 A"}, {"identifier": "D", "content": "10 A"}] | ["B"] | null | Total power is <br><br>= (15 × 45) + (15 × 100) + (15 × 10) + (2 × 1000)
<br><br>= 4325 W
<br><br>$$ \therefore $$ Current = $${{4325} \over {220}}$$ = 19.66 A $$ \simeq $$ 20 A | mcq | jee-main-2020-online-7th-january-evening-slot | 9,775 |
MHbXmErNaaT1l5yvVHjgy2xukeu2jla2 | physics | current-electricity | electric-power-and-heating-effect-of-current | A battery of 3.0 V is connected to a resistor dissipating 0.5 W of power. If the terminal voltage of the battery is 2.5 V, the power dissipated within the internal resistance is : | [{"identifier": "A", "content": "0.50 W"}, {"identifier": "B", "content": "0.072 W"}, {"identifier": "C", "content": "0.10 W"}, {"identifier": "D", "content": "0.125 W"}] | ["C"] | null | P<sub>R</sub> = 0.5 W
<br><br>$$ \Rightarrow $$ i<sup>2</sup>R = 0.5 W
<br><br>iR = 2.5
<br><br>$$ \Rightarrow $$ i = 0.2 A & R = 12.5 $$\Omega $$
<br><br>Also, V = E – ir
<br><br>$$ \Rightarrow $$ 2.5 = 3 – (0.2)r
<br><br>$$ \Rightarrow $$ r = 2.5 $$\Omega $$
<br><br>Power dissipated in internal resistance
<br><br... | mcq | jee-main-2020-online-4th-september-morning-slot | 9,776 |
oDf2IL8d2d7FVXnwsv1kmipckqw | physics | current-electricity | electric-power-and-heating-effect-of-current | A resistor develops 500 J of thermal energy in 20 s when a current of 1.5A is passed through it. If the current is increased from 1.5A to 3A, what will be the energy developed in 20 s. | [{"identifier": "A", "content": "1000 J"}, {"identifier": "B", "content": "2000 J"}, {"identifier": "C", "content": "1500 J"}, {"identifier": "D", "content": "500 J"}] | ["B"] | null | $${H_1} = i_1^2R\Delta t$$<br><br>$${H_2} = i_2^2R\Delta t$$<br><br>$$ \Rightarrow {{{H_1}} \over {{H_2}}} = {{i_1^2} \over {i_2^2}}$$<br><br>$$ \Rightarrow {{500} \over {{H_2}}} = {\left( {{1 \over 2}} \right)^2}$$<br><br>$$ \Rightarrow {H_2} = 2000J$$ | mcq | jee-main-2021-online-16th-march-evening-shift | 9,777 |
Oiu2ZRbw46fGrw79NP1kmiprbx8 | physics | current-electricity | electric-power-and-heating-effect-of-current | The energy dissipated by a resistor is 10 mJ in 1 s when an electric current of 2 mA flows through it. The resistance is ___________$$\Omega$$. (Round off to the Nearest Integer) | [] | null | 2500 | <p>Given, energy dissipated by a resistor, H = 10 mJ = 10 $$\times$$ 10<sup>$$-$$3</sup> J</p>
<p>Time, t = 1 s</p>
<p>Electric current, I = 2 mA = 2 $$\times$$ 10<sup>$$-$$3</sup> A</p>
<p>Resistance, R = ?</p>
<p>According to Joule's law of heating,</p>
<p>H = I<sup>2</sup>Rt</p>
<p>$$ \Rightarrow R = {H \over {{I^2}... | integer | jee-main-2021-online-16th-march-evening-shift | 9,778 |
1krunnce6 | physics | current-electricity | electric-power-and-heating-effect-of-current | An electric bulb rated as 200 W at 100 V is used in a circuit having 200 V supply. The resistance 'R' that must be put in series with the bulb so that the bulb delivers the same power is _____________ $$\Omega$$. | [] | null | 50 | Power, $$P = {{{V^2}} \over {{R_B}}}$$<br><br>$${R_B} = {{{V^2}} \over P} = {{100 \times 100} \over {200}}$$<br><br>$${R_B} = 50\Omega $$<br><br> <img src="https://res.cloudinary.com/dckxllbjy/image/upload/v1734264618/exam_images/ea2nafn2gmwz6ppiff4c.webp" style="max-width: 100%;height: auto;display: block;margin: 0 au... | integer | jee-main-2021-online-25th-july-morning-shift | 9,779 |
1ks19va2d | physics | current-electricity | electric-power-and-heating-effect-of-current | The resistance of a conductor at 15$$^\circ$$C is 16$$\Omega$$ and at 100$$^\circ$$C is 20$$\Omega$$. What will be the temperature coefficient of resistance of the conductor? | [{"identifier": "A", "content": "0.010$$^\\circ$$C<sup>$$-$$1</sup>"}, {"identifier": "B", "content": "0.033$$^\\circ$$C<sup>$$-$$1</sup>"}, {"identifier": "C", "content": "0.003$$^\\circ$$C<sup>$$-$$1</sup>"}, {"identifier": "D", "content": "0.042$$^\\circ$$C<sup>$$-$$1</sup>"}] | ["C"] | null | 16 = R<sub>0</sub> [1 + $$\alpha$$ (15 $$-$$ T<sub>0</sub>)]<br><br>20 = R<sub>0</sub> [1 + $$\alpha$$ (100 $$-$$ T<sub>0</sub>)]<br><br>Assuming T<sub>0</sub> = 0$$^\circ$$C, as a general convention.<br><br>$$\Rightarrow$$ $${{16} \over {20}} = {{1 + \alpha \times 15} \over {1 + \alpha \times 100}}$$<br><br>$$\Right... | mcq | jee-main-2021-online-27th-july-evening-shift | 9,780 |
1ktacctwh | physics | current-electricity | electric-power-and-heating-effect-of-current | In the given figure, the emf of the cell is 2.2 V and if internal resistance is 0.6$$\Omega$$. Calculate the power dissipated in the whole circuit :<br/><img src="data:image/png;base64,UklGRngTAABXRUJQVlA4IGwTAAAwYQCdASoGAeMAPm0ylUgkIqShJHLLqJANiWlu4WguMxnZ1yfpH/JfyJ8E/65+SvoT+HfMf2n8m/7h6zf8r0nWbP7AfeP5d/Vv9//d/3V+Af7... | [{"identifier": "A", "content": "1.32 W"}, {"identifier": "B", "content": "0.65 W"}, {"identifier": "C", "content": "2.2 W"}, {"identifier": "D", "content": "4.4 W"}] | ["C"] | null | <img src="https://res.cloudinary.com/dckxllbjy/image/upload/v1734266056/exam_images/nkmcfgr8dqchd3uges5i.webp" style="max-width: 100%;height: auto;display: block;margin: 0 auto;" loading="lazy" alt="JEE Main 2021 (Online) 26th August Morning Shift Physics - Current Electricity Question 162 English Explanation 1"><br><i... | mcq | jee-main-2021-online-26th-august-morning-shift | 9,781 |
1ktbr1p8k | physics | current-electricity | electric-power-and-heating-effect-of-current | An electric bulb of 500 watt at 100 volt is used in a circuit having a 200 V supply. Calculate the resistance R to be connected in series with the bulb so that the power delivered by the bulb is 500 W. | [{"identifier": "A", "content": "20 $$\\Omega$$"}, {"identifier": "B", "content": "30 $$\\Omega$$"}, {"identifier": "C", "content": "5 $$\\Omega$$"}, {"identifier": "D", "content": "10 $$\\Omega$$"}] | ["A"] | null | 500 watt at 100 v<br><br> <img src="https://res.cloudinary.com/dckxllbjy/image/upload/v1734264155/exam_images/wwxrp1djjw35p2zrgkwe.webp" style="max-width: 100%;height: auto;display: block;margin: 0 auto;" loading="lazy" alt="JEE Main 2021 (Online) 26th August Evening Shift Physics - Current Electricity Question 160 Eng... | mcq | jee-main-2021-online-26th-august-evening-shift | 9,782 |
1ktjr8nv5 | physics | current-electricity | electric-power-and-heating-effect-of-current | A resistor dissipates 192 J of energy in 1s when a current of 4A is passed through it. Now, when the current is doubled, the amount of thermal energy dissipated in 5s in _________ J. | [] | null | 3840 | E = i<sup>2</sup>Rt<br><br>192 = 16 (R) (1)<br><br>R = 12$$\Omega$$<br><br>E<sub>1</sub> = (8)<sup>2</sup> (12) (5)<br><br>= 3840 J | integer | jee-main-2021-online-31st-august-evening-shift | 9,783 |
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