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. How Waves Interact with Matter Waves interact with matter in several ways. The interactions occur when waves pass from one medium to another. The types of interactions are reﬂection, refraction, and diffraction. Each type of interaction is described in detail below. You can see animations of the three types at this U...
Waves bend as they enter a new medium because they start traveling at a different speed in the new medium. For 25 example, light travels more slowly in water than in air. This causes it to refract when it passes from air to water or from water to air. Q: Where would the ﬁsh appear to be if the man looked down at it fr...
a crossword puzzle of terms relating to wave interactions. Include at least seven different terms. You can use the puzzle maker at the following URL. Then exchange and solve puzzles with a classmate. http://puzzlemaker.disc overyeducation.com/CrissCrossSetupForm.asp Review 1. What is reﬂection? What happens if waves s...
pass through each other, the crests and troughs cancel each other out to produce a wave with zero amplitude. You can see an animation of destructive interference at this URL: htt p://phys23p.sl.psu.edu/phys_anim/waves/embederQ1.20200.html 28 www.ck12.org Concept 8. Wave Interference FIGURE 8.1 Standing Waves Waves may...
your answers. http://www.physicsclassroom.com/class/waves/u10l3c.cfm Review 1. What is wave interference? 2. Create a table comparing and contrasting constructive and destructive interference. 30 www.ck12.org Concept 8. Wave Interference 3. What are standing waves? How do they form? References 1. Christopher Auyeung.....
f. Because f = 1 l = vT! v = l T, these are mathematically the same: T = l 1 T = l f The wave equation says distance wavelength is equal to wave speed multiplied by period T. http://demonstrations.wolfram.com/SpeedOfSound/ 32 www.ck12.org Concept 9. Wave Speed FIGURE 9.1 Illustrative Example 1 a. The ripple tank arm i...
0 m s. Answer: VL = 874; 635:57! 8:7 105. The velocity of light is indeed a good deal greater than the velocity of Vs sound in air. In fact, the velocity of light in vacuum is the greatest velocity that exists. No material object can travel at this velocity! We will discuss these ideas in Chapter 23 (The Special Theory...
enter their ears. The tree above generated sound waves when it fell to the ground, so it made sound according to the scientiﬁc deﬁnition. But the sound wasn’t detected by a person’s ears if there was nobody in the forest. So the answer to the riddle is both yes and no! How Sound Waves Begin All sound waves begin with ...
sounds you hear have traveled to your ears through the water. Some solids, including glass and metals, are very good at transmitting sounds. Foam rubber and heavy fabrics, on the other hand, tend to mufﬂe sounds. They absorb rather than pass on the sound energy. Q: How can you tell that sounds travel through solids? A...
infrasound and ultrasound. A marching band passes you as it parades down the street. You heard it coming from several blocks away. Now that the different instruments have ﬁnally reached you, their distinctive sounds can be heard. The tiny piccolos trill their bird-like high notes, and the big tubas rumble out their bo...
dark. This is how they avoid ﬂying into walls and trees and also how they ﬁnd ﬂying insects to eat. Summary • How high or low a sound seems to a listener is its pitch. Pitch, in turn, depends on the frequency of sound waves. • High-frequency sound waves produce high-pitched sounds, and low-frequency sound waves produc...
. The speed of sound may be very different through other matter or at other temperatures. Speed of Sound in Different Media Sound waves are mechanical waves, and mechanical waves can only travel through matter. The matter through which the waves travel is called the medium (plural, media). The Table 12.1 gives the spee...
in a given amount of time. The speed of sound in dry air at 20 °C is 343 meters per second. • Generally, sound waves travel most quickly through solids, followed by liquids, and then by gases. • For a given medium, sound waves travel more slowly at lower temperatures. Vocabulary • speed of sound : Speed at which sound...
, the person pushing will start just at the very back of the swing. In other words, the frequency of how often they push is exactly the same as the frequency of the swing. Suppose they do not push at the right time, but instead push at some other frequency. That would mean that sometimes they are pushing forward when t...
down some distance from the neck of the guitar, will also be set into vibration. When this condition is met, both strings are vibrating with the same frequency. We call this phenomenon sympathetic vibration. 47 www.ck12.org MEDIA Click image to the left for more content. FIGURE 13.5 https://www.youtube.com/watch?v=tnS...
crystalline mineral such as galena. FIGURE 13.7 An old crystal radio set. In modern times, the air is ﬁlled with all manner of radio waves. In order to listen to your favorite radio station, you must tune your radio to resonate with only the frequency of the radio station. When you hear the tuning number of a radio st...
L, the length of the unstretched string, is equal to one-half the wavelength, which is 1 2 l1 = L! l1 = 2L: 49 www.ck12.org FIGURE 13.8 The second harmonic contains an entire wavelength 2 2 l2 = L! l2 = L as shown in Figure below. FIGURE 13.9 And the third harmonic contains one and one-half wavelengths 3 2 l3 = L! l3 ...
shown in Figure above The third harmonic contains ﬁve-fourths wavelengths as shown in Figure below. If the pattern continues, then the fourth harmonic will have a wavelength of 7 expressions for the length of the string in terms of the wavelength, a simple pattern emerges 1 We can express the condition for resonance a...
of the “quality” or “timbre” of musical instruments depends upon the combination of the various overtones produced by the instrument. Check Your Understanding 1. A tuning fork has a frequency of 512 Hz stamped on it. When it is struck, a student claims she can hear higher frequencies from the tuning fork. Is this poss...
. They therefore have the same resonant conditions as a string ﬁxed at only one end, for n = 1; 3 ln or ln = 4 n L. A closed pipe supporting the ﬁrst harmonic (the fundamental frequency) will ﬁt one-fourth of the wavelength, the second harmonic will ﬁt three-fourths, and so on, as shown in Figure below. Compare these p...
ogg. Public Domain http://commons.wikimedia.org/wiki/File:Tacoma_Narrows_Bridge_de 3.. http://commons.wikimedia.org/wiki/File:Tacoma-narrows-bridge-collapse.jpg. Public Domain 4. Russell James Smith (Flickr: russelljsmith). http://www.ﬂickr.com/photos/russelljsmith/2146210247/. CC-BY 2.0 5. CK-12 Foundation - Raymond C...
2L, where n is an integer Guidance In the case of a tube that is open at one end, a node is forced at the closed end (no air molecules can vibrate up and down) and an antinode occurs at the open end (here, air molecules are free to move). A different spectrum of standing waves is produced. For instance, the fundamental...
Time for Practice 1. 2. Aborigines, the native people of Australia, play an instrument called the Didgeridoo like the one shown above. The Didgeridoo produces a low pitch sound and is possibly the world’s oldest instrument. The one shown above is about 1.3 m long and open at both ends. a. Knowing that when a tube is o...
, obviously, is that it 58 www.ck12.org Concept 14. Sound in a Tube is much easier to draw transverse waves rather than longitudinal). Note that the tube is CLOSED at one end and OPEN at the other. (b) Calculate the frequencies of the ﬁrst three harmonics played in this tube, if the speed of sound in the tube is 340 m/...
the referral attribution link http://www.ck12.org/saythanks (placed in a visible location) in addition to the following terms. Except as otherwise noted, all CK-12 Content (including CK-12 Curriculum Material) is made available to Users in accordance with the Creative Commons Attribution-Non-Commercial 3.0 Unported (C...
the Force Be with You A familiar example may help you understand the vibrating electric and magnetic ﬁelds that make up electromagnetic waves. Consider a bar magnet, like the one in the Figure 1.1. The magnet exerts magnetic force over an area all around it. This area is called a magnetic ﬁeld. The ﬁeld lines in the d...
a transverse wave. However, unlike a mechanical transverse wave, which can only travel through matter, an electromagnetic transverse wave can travel through empty space. When waves travel through matter, they lose some energy to the matter as they pass through it. But when waves travel through space, no energy is lost...
��ected, refracted, or diffracted. Or they may be absorbed by matter and converted to other forms of energy. • The most important source of electromagnetic waves on Earth is the sun. Many other sources of electromag- netic waves depend on technology. Vocabulary • electromagnetic radiation : Transfer of energy by electr...
space. That speed, called the speed of light, is about 300 million meters per second (3.0 x 10 8 m/s). Nothing else in the universe is known to travel this fast. The sun is about 150 million kilometers (93 million miles) from Earth, but it takes electromagnetic radiation only 8 minutes to reach Earth from the sun. If ...
Its frequency can be found by substituting these values into the frequency equation: Frequency = 3:0108 m/s 3:0 m = 1:0 108 waves/s, or 1.0 10 8 Hz Q: What is the wavelength of an electromagnetic wave that has a frequency of 3.0 10 8 hertz? A: Use the wavelength equation: Wavelength = 3:0108 m/s 3:0108 waves/s = 1:0 m...
and then go to the zoo. The boys may not realize it, but they will be bombarded by electromagnetic radiation as they ride their bikes and walk around the zoo grounds. The only kinds of radiation they can detect are visible light, which allows them to see, and infrared light, which they feel as warmth on their skin. Q:...
, and energy levels of light fall in between those of radio waves on the left and X rays and gamma rays on the right. Q: Which type of light has the longest wavelengths? A: Infrared light has the longest wavelengths. Q: What sources of infrared light are shown in the diagram? A: The sources in the diagram are people an...
light is reﬂected from a smooth surface, it may form an image. An image is a copy of an object that is formed by reﬂected (or refracted) light. Q: Is an image an actual object? If not, what is it? A: No, an image isn’t an actual object. It is focused rays of light that make a copy of an object, like a picture projecte...
��ectionMirrors.htm FIGURE 4.2 Law of Reﬂection One thing is true of both regular and diffuse reﬂection. The angle at which the reﬂected rays leave the surface is equal to the angle at which the incident rays strike the surface. This is known as the law of reﬂection. The law is illustrated in the Figure 4.3 and also in...
. What is an image? 2. Identify the object and the image in the Figure 4.4. Which type of reﬂection formed the image: regular reﬂection or diffuse reﬂection? How do you know? FIGURE 4.4 3. What is the law of reﬂection? 4. Label the angle of incidence and the angle of reﬂection in the Figure 4.5. 14 www.ck12.org Concept...
normal line is the line perpendicular to the medium interface. 16 www.ck12.org Concept 5. Refraction of Light In the sketch below, light wave fronts are moving upward from the bottom of the page and encounter a boundary into a more optically dense medium. The light waves bend toward the normal line. Because the right ...
dense than a vacuum, when sunlight passes from the vacuum of space into our atmosphere, it bends slightly towards the normal. When the sun is below the horizon and thus not visible on a direct line, the light path will bend slightly and thus make the sun visible by refraction. Observers can see the sun before it actua...
angle of refraction? 2. A ray of light passes from air into water at an incident angle of 60:0. Find the angle of refraction. 3. Light passes from water into a block of transparent plastic. The angle of incidence from the water is 31 and the angle of refraction in the block is 27. What is the index of refraction for t...
occur. Total internal reﬂection allows the light to travel down the optical ﬁber and not pass through the sides of the tube. The light continuously reﬂects from the inside of the tube and eventually comes out the end. Optical ﬁbers make interesting lamps but they are also used to transport telephone and television sig...
. • If the angle of incidence becomes large enough that the angle of refraction equals 90, the light ray will not enter the new medium with the smaller angle of refraction. • Total internal reﬂection means the light ray will not enter the new medium but will be completely reﬂected back into the original medium. Practic...
is passing from a medium of higher index of refraction into a medium of lower index of refraction is completely reﬂected by the boundary between the two media. • critical angle: The smallest angle of incidence at which a light ray passing from one medium to another less refractive medium will be totally reﬂected from ...
from these triangles are the width of the slit, w, the wavelength, l, the distance from the central bright spot to the ﬁrst dark band, x, and the distance from the center of the slit to back wall, L. The relationship of these four values is L or l = wx w = x L. l Example Problem: Monochromatic light of wavelength 605 ...
same interference pattern as when it passes through a single slit. (a) True (b) False 4. If monochromatic light passes through a 0.050 mm slit and is projected onto a screen 0.70 m away with a distance of 8.00 mm between the central bright band and the ﬁrst dark band, what is the wavelength of the light? 5. A krypton ...
However, the last particle of the medium at the back corner of the barrier will create circular waves from that point, called the point source. This can be seen in the image below. This phenomenon is called diffraction, and it occurs in liquid, sound, and light waves. While the waves become circular waves at the point...
�s, light was assumed to be a particle. There was a signiﬁcant amount of evidence to point to that conclusion, and famous scientist Isaac Newton’s calculations all support the particle theory. In 1803, however, Thomas Young performed his famous Double Slit Experiment to prove that light was a wave. Young shined a light...
which means that the ratios of corresponding sides are the same. The ratio of x to L in the red triangle is equal to the ratio of l to d in the blue triangle. For proof of this, visit http://www.physicsclassroom.com/class/light/u12l3c.cfm. From this, we can determine that the wavelength is dependent on x, d, and L: 29...
ﬁrst bright band 3:00 102 m from the central bright spot. If the screen is 0.650 m away, what is the wavelength of this light? (a) 510 nm (b) 390 nm (c) 430 nm (d) 460 nm 4. Violet light falls on two slits separated by 1:90 105 m. A ﬁrst order bright line appears 13.2 mm from the central bright spot on a screen 0.600 ...
by diffraction gratings. • Use diffraction grating interference patterns to calculate the wavelength of light. Suppose we had a light bulb that emitted exactly four frequencies of light; one frequency in each of the colors red, yellow, green, and blue. To our eye, this bulb would appear white because the combination o...
, the smaller the distance between the lines, and the greater the separation of images on the screen. L = sin q, using the small angle approximation theorem.) Example Problem: A good diffraction grating has 2500 lines/cm. What is the distance between two lines on the grating? Solution: d = 1 2500 cm1 = 0:00040 cm Examp...
ﬁne parallel grooves or slits and used to produce optical spectra by diffraction. References 1. CK-12 Foundation - Samantha Bacic, using light bulb images copyright Ruslan Klimovich, 2013. http:// www.shutterstock.com. Used under license from Shutterstock.com 2. Candace (Flickr: cosmiccandace). http://www.ﬂickr.com/ph...
returns to a lower energy level and gives off electromagnetic energy, the energy is released as a discrete “packet” of energy. We now call such a packet of energy a photon. According to Einstein, a photon resembles a particle but moves like a wave. You can see this in the Figure 10.1. The theory posits that waves of p...
proposed by Albert Einstein that electromagnetic energy is released in discrete packets of energy (now called photons) that act like waves. Practice Watch the animation “Let There Be Light” at the following URL. Then create a timeline of ideas and discoveries about the nature of light. http://www.abc.net.au/science/ex...
Except as otherwise noted, all CK-12 Content (including CK-12 Curriculum Material) is made available to Users in accordance with the Creative Commons Attribution-Non-Commercial 3.0 Unported (CC BY-NC 3.0) License (http://creativecommons.org/ licenses/by-nc/3.0/), as amended and updated by Creative Commons from time to...
explain why? A: When the air is very dry, electric charges are more likely to build up objects because they cannot travel easily through the dry air. This makes a shock more likely when you touch another object. Static Discharge What happens when you have become negatively charged and your hand approaches the metal do...
charge http://www.youtube.com/watch?v=Y8oN0YFAXWQ&feature=related MEDIA Click image to the left for more content. Summary • Static electricity is a buildup of electric charges on objects. It occurs when electrons are transferred from one object to another. • A sudden ﬂow of electrons from one charged object to another ...
or repulsion between charged particles is called electric force. The strength of electric force depends on the amount of electric charge on the particles and the distance between 4 www.ck12.org Concept 2. Electric Charge and Electric Force FIGURE 2.1 them. Larger charges or shorter distances result in greater force. Y...
de Graff generator at this URL: http://www.youtube.com/watch?v=SREXQWAIDJk MEDIA Click image to the left for more content. Q: Why is the man’s hair standing on end? A: All of the hairs have all become negatively charged, and like charges repel each other. Therefore, the hairs are pushing away from each other, causing ...
charged. 8 www.ck12.org Polarization Concept 3. Transfer of Electric Charge Assume that you have walked across a wool carpet in rubber-soled shoes and become negatively charged. If you then reach out to touch a metal doorknob, electrons in the neutral metal will be repelled and move away from your hand before you even...
www.ck12.org FIGURE 3.3 • Three ways electrons can be transferred are conduction, friction, and polarization. In each case, the total charge remains the same. This is the law of conservation of charge. • Conduction occurs when there is direct contact between materials that differ in their ability to give up or accept ...
matter when charged. • Describe how to charge an object. • Deﬁne conductors and insulators. • Understand the difference between conduction and induction. • Summarize the forces between charged objects. Lightning is the discharge of static electricity that has built up on clouds. Every year, the earth experiences an av...
in tremendous bolts of lightning. A common method of producing charge in the lab is to rub cat or rabbit fur against stiff rubber, producing a negative charge on the rubber rod. If you hold a rubber rod on one end and rub only the tip of the other end with a fur, you will ﬁnd that only the tip becomes charged. The ele...
leaves. The leaves will separate while the rod is nearby. No extra electrons were added to the electroscope, meaning that the electrons in the electroscope will redistribute when the negatively charged rod is taken away. The leaves return to neutral, and they stop repelling each other. If the rod touches the knob, the...
charge as the originally charged object, while charging by conduction gives them both the same charge. Summary • Electric charges exist with the atom. • Atoms contain light-weight, loosely held, negatively charged particles called electrons and heavier, tightly- held, positvely charged particles called protons. • When...
(d) grounding. 4. Two objects each carry a charge and they attract. What do you know about the charge of each object? (a) They are both charged positively. (b) They have opposite charged from each other. (c) They are both charged negatively. (d) Any of the above are possible. 5. A material that easily allows the ﬂow o...
atomic nucleus, or they may break free and exist as a free electron. • protons: A stable, positively charged, sub-atomic particle, found in atomic nuclei in numbers equal to the atomic number of the element. • neutral: A neutral particle, object, or system is one that has a net electric charge of zero. • conductors: M...
electric cars is the low cost of operation, which may become an ever bigger advantage as gas prices climb. Energy costs for electric cars average about one-third of the cost for gasoline engine cars, but they can only travel about 200 miles per charge at this point. These cars run using the science of electrical charg...
the force is repulsive. This makes sense, because both objects have a positive charge. Example Problem: 6:0 106 C. Calculate the total force on q 2. In the sketch below, the charges are q1 = 10:0 106 C; q2 = 2:0 106 C, and q3 = Solution: Fe = Kq1q2 d2 = (9:0109 Nm2=C2)(10:0106 C)(2:0106 C) (2:0 m)2 = 0:045 N (towards ...
between them is doubled, what does the force become? 2. What is the electrical force between two balloons, each having 5.00 C of charge, that are 0.300 m apart? 3. Two spheres are charged with the same charge of -0.0025 C and are separated by a distance of 8.00 m. What is the electrical force between them? 4. A red fo...
strength of the electric ﬁeld is determined point by point and can only be identiﬁed by the presence of test charge. When a positive test charge, q t, is placed in an electric ﬁeld, the ﬁeld exerts a force on the charge. The ﬁeld strength can be measured by dividing the force by the charge of the test charge. Electric...
2:0 108 C experiences a force of 0.060 N to the right in an electric ﬁeld. What is the magnitude and direction of the ﬁeld? 3. A positive charge of 5:0 104 C is in an electric ﬁeld that exerts a force of 2:5 104 N on it. What is the magnitude of the electric ﬁeld at the location of the charge? 4. If you determined the...
constant (uniform) when we remain close to the surface of the Earth. As of yet, we have not encountered an example of a uniform electric ﬁeld E. But that won’t stop us from making a prediction! Since the gravitational potential energy of a mass m in a uniform gravitational ﬁeld is PEgravity = (mg)h, we predict the ele...
. If a metal plate is connected to the positive terminal of the battery, and another metal plate is connected to the negative terminal of the battery, and the two plates brought closely together, a parallel plate arrangement (parallel-plate conductors) can be constructed with a uniform electric ﬁeld between the plates ...
energy is PEgravitational = mgh. We can compare the terms in the gravitational and electrical cases as follows Thus, we see that our prediction for the equation of electric potential energy stated in the introduction of the lesson, was correct! Check Your Understanding 1a. The electrical potential at the negative plat...
and therefore gains kinetic energy. Just as an object that is dropped gains kinetic energy and loses potential energy, so does the electron. Recall our discussion of the conservation of energy. As long as the total energy remains conserved, the sum of the initial kinetic and potential energies must equal the sum of th...
again: 1. The electric potential is deﬁned as the energy per unit charge! Vx1 = PEx1 q. 29 www.ck12.org 2. The electric potential difference (the voltage) is Vf Vi = PE f 3. An arbitrary reference level must be established for zero potential (just as in the case of gravitational potential q PEi q energy). 4. The units...
. Transposing terms, the electric ﬁeld is E = V volts per meter volts If we compare the units for the electric ﬁeld N m, we see that a (N m) is equivalent to a (C V ). A Joule can therefore be expressed as a Coulomb-Volt. Recall that work, measured in Joules, is the product of charge and voltage W = qDV. meter! V m. C ...
105 kg = 1:95 107 V C kgm. b. Show that the units V C kgm are equivalent to the units m s2. Answer : V C kg m = J kg m = N m kg m = N kg = kg m s2 kg = m s2 c. The plates have separation of 8.00 mm. Determine the velocity of the particle when it reaches the negative plate Answer : 31 www.ck12.org FIGURE 7.4 Illustrativ...
a Free-Body-Diagram (FBD) of the situation. The electrostatic force that acts on the electron points upward and the gravitational force that acts upon on the electron points downward. The electron is suspended motionless (or moves with a constant velocity) when the net force on the electron is zero. 33 The net force o...
Answer : Protons are the only charges inside the nucleus of an atom and so the alpha particle must be positively charged. A helium nucleus contains two protons (and two neutrons) with a total charge of 2(1:60 1019 C). The alpha particle must slow down due to the electrostatic repulsion from the positive plate. It must...
:60 1019 J) = 5:92 1014 J 1 2 1 2 (1:67 1027 kg)v2 = 5:92 1014 J! mpv2 = 5:92 1014 J! v = 8:4 106 m s References 1. CK-12 Foundation - Raymond Chou.. CC-BY-NC-SA 3.0 2. User:Asim18/Wikimedia Commons. http://commons.wikimedia.org/wiki/File:02_-_Single_Energizer_Ba ttery.jpg. CC-BY 3.0 3. CK-12 Foundation - Raymond Chou....
-12 Marks”) are trademarks and service marks of CK-12 Foundation and are protected by federal, state, and international laws. Any form of reproduction of this book in any format or medium, in whole or in sections must include the referral attribution link http://www.ck12.org/saythanks (placed in a visible location) in ...
circuit carries depends on the number and power of electrical devices connected to the circuit. Home circuits generally have a safe upper limit of about 20 or 30 amps. 1 Parts of an Electric Circuit All electric circuits have at least two parts: a voltage source and a conductor. They may have other parts as well, such...
URE 1.2 Q: Only one of the circuit symbols above must be included in every circuit. Which symbol is it? A: The battery symbol (or a symbol for some other voltage source) must be included in every circuit. Without a source of voltage, there is no electric current. Summary • An electric circuit is a closed loop through w...
, between the terminals of a battery, as in Figure below. The rate I = DQ Dt at which charges ﬂow within 4 www.ck12.org Concept 2. Electric Current a conducting wire past any point in the wire is deﬁned as the electric current. The unit of current is coulombs Ampere, 1775-1836), Figure below. second which is called the...
-12 Foundation - Ira Nirenberg.. CC-BY-NC-SA 3.0 3.. http://commons.wikimedia.org/wiki/File:Andre-marie-ampere2.jpg. public domain. CC-BY 2.0 6 www.ck12.org Concept 3. Electric Resistance CONCEPT 3 Electric Resistance • Deﬁne resistance and identify the SI unit for resistance. • List factors that affect resistance. • E...
particles have less kinetic energy, so they move more slowly. Therefore, they are less likely to collide with moving electrons in current. Materials called superconductors have virtually no resistance when they are cooled to extremely low temperatures. Is Resistance Good or Bad? Resistance can be helpful or just a dra...
4 • Explain Ohm’s law. • Use Ohm’s law to calculate current from voltage and resistance. www.ck12.org Ohm’s Law Look at the water spraying out of this garden hose. You have to be careful using water around power tools and electric outlets because water can conduct an electric current. But in some ways, water ﬂowing th...
10 ohms of resistance, how much current is ﬂowing through the wire? A: Substitute these values into the equation for current: Current = 120 volts 20 ohms = 12 amps Summary • According to Ohm’s law, greater voltage results in more current and greater resistance results in less current. • Ohm’s law can be represented by...
. These terms will be explained over the course of this lesson. Resistance and Ohm’s Law When a potential difference is placed across a metal wire, a large current will ﬂow through the wire. If the same potential difference is placed across a glass rod, almost no current will ﬂow. The property that determines how much ...
to the left for more content. 1. What happens to current ﬂow when voltage is increased? 2. What happens to current ﬂow when resistance is increased? This website contains instruction and guided practice for Ohm’s Law. http://www.wisc-online.com/Objects/ViewObject.aspx?ID=DCE11904 Review 1. If the potential stays the s...
I. It is possible to determine the power dissipated in a single resistor if we combine this expression with Ohm’s Law, V = IR. This becomes particularly useful in circuits with more than one resistor, to determine the power dissipated in each one. Combining these two equations, we get an expression for electric power ...
is dissipated when a current of 1.00 A passes through a power line whose resistance is 1.00 W? P = I2R = (1:00 A)2(1:00 W) = 1:00 Watts The power loss is reduced tremendously by reducing the magnitude of the current through the resistance. Power companies must transmit the same amount of energy over the power lines bu...
to a resistor in a time period is equal to the electric power multiplied by time, E = Pt, and can also be calculated using E = I2Rt. • Electric companies measure their energy sales in a large number of joules called a kilowatt hour (kWh) which is equivalent to 3:6 106 J. Practice The following video is on electrical e...
circuits in series or parallel and explain why. This photo is of the interior of the control room for a nuclear power plant. Many of the meters are reading information about the water temperature and the nuclear reaction that is occurring, but the majority of the meters are reading data about the electric energy being...
In this video, a circuit is established with a power supply, which also has an attached voltmeter, and a lamp (resistor). After the circuit is established, a voltmeter and an ammeter are alternately placed in the circuit. Follow up questions: 1. What happens when the ammeter is connected in parallel with the lamp? 2. ...
There are a number of safety devices used in electrical circuits to limit the current; fuses, circuit breakers, and surge suppressors. When fuses, such as those shown above, are placed in an electrical circuit, all the current must pass through the wire in the fuse. Series Circuits Electrical circuits are often modele...
60 W Therefore, the total current and the current through each resistor is I = V R = 120 V 60 W = 2:0 A: The individual voltage drops can be calculated using the current through each resistor and each resistor’s individual resistance. V1 = I1R1 = (2:0 A)(30 W) = 60 V V2 = I2R2 = (2:0 A)(15 W) = 30 V V3 = I3R3 = (2:0 A...
the circuit is 3.00 A. (a) What is the equivalent resistance of the circuit? (b) What is the current through the 5.00W resistor? (c) What is the total voltage drop for the entire circuit? • series circuit: One in which all of the current must pass through every resistor in the circuit. References 1. Image copyright se...
How much power does each resistor dissipate? Answer: Each resistor has different voltage across it, but the same current. So, using Ohm’s law, convert the power formula into a form that does not depend on voltage. 25 www.ck12.org P = IV = I(IR) = I2R: P90 W = I2 P10 W = I2 90 WR90 W = (0:2 A)2(90 W) = 3:6W 10 WR10 W =...
ﬂowing out of the battery? c. In order to increase current in your circuit, which two resistors would you remove? 3. Given the resistors above and a 12 V battery, how could you make a circuit that draws 0.0594 A? Answers to Selected Problems 1. a. 224 V b. 448 W c. 400 W by 100 W and 48 W by 12 W 2. a. 0.013 A b. 0.27...

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