| What is Unit cell? |
| Smallest repeating structure in a crystal that has all properties similar to crystal structure |
| What is Atomic basis? |
| Every point in space lattice is associated with one or more atoms is called atomic basis |
| What is Space lattice? |
| Infinite 3d array of points in which every point has surroundings identical with that of every other point. |
| What is Susceptibility? |
| Magnetic susceptibility is the measure of extent to which a material may be magnetized by applied magnetic field. |
| What are Diamagnetic materials? |
| Materials which weakly repell magnetic field and do not retain magnetic properties when external field is removed. |
| What are Paramagnetic materials? |
| Materials which are slightly attracted by a magnetic field but do not retain the magnetic properties when external field is removed. |
| What are Ferromagnetic materials? |
| Materials which are strongly attracted by magnetic field and retain their magnetic properties when external field is removed. |
| What are ferrimagnetic materials? |
| Materials in which unequal opposite magnetic moments are present. |
| What is Flux? |
| Flux is the number of magnetic field lines passing through a surface. |
| What is Flux density? |
| The number of magnetic field lines passing through unit area. |
| What is domain? |
| A group of atomic magnets pointing in the same direction is called domain. |
| What is p type? |
| Semiconductors doped with trivalent atoms |
| what is n type? |
| Semiconductors doped with pentravalent atoms |
| What is on pn junction diode? |
| Interface between p type and n type semiconductor |
| What is forward biased? |
| In forward biased the p side of the diode is attached to positive terminal and n side to negative terminal of the battery. |
| What is reversed biased? |
| In reverse biased the p side of diode is attached to negative terminal and n side is attached to positive terminal |
| What is Band gap? |
| Distance between valence band of electrons and conduction band. |
| What is Fermi level? |
| It is the highest energy level that an electron can occupy at absolute zero temperature. |
| What is valence band? |
| Highest level of completely filled band by electrons |
| What is conduction band? |
| Lowest level of empty band.Conductivity of semiconductor increases with increase in temperature.Probability of finding electron in conduction band and valence band is zero |
| What is formula for time period in Torsional Pendulum? |
| T = 2π√l/3g |
| What is formula for time period Compound Pendulum? |
| T= 2π√l/g |
| What is radius of gyration? |
| Radial distance to a point which would have moment of inertia same as the distribution of mass if the whole mass was concentrated at that point. |
| What is band gap? |
| The energy difference between highest level of valence band and lowest level of conduction band. |
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| What is Fermi energy level? |
| It is highest energy level that an electron can occupy at absolute zero temperature. |
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| What is Fermi energy? |
| Maximum energy that an electron can possess at absolute zero temperature. |
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| What is potential barrier? |
| Postential difference developed accross the pn junction due to diffusion of electrons from n region to p region. |
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| What is depletion region? |
| Gap created across the pn junction which is devoid of charge carriers. It contains immobile charge carriers. |
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| What is doping? |
| Doping is introduction of impurities to intrinsic semiconductors to vary the number of number of electrons and holes. |
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| Why circular pattern is observed? |
| Because of the same thickness of air from all sides |
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| What if we increase the wavelength |
| The diameter of the ring will increase |
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| What is Newton's Rings? |
| It a phenomenon in which interference pattern is created by reflection of light between two surfaces , the spherical surface and the flat surface. |
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| What is specific heat capacity? |
| The amount of heat required to raise the temperature of 1 g of a substance by 1 degree celcius is called specific heat. |
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| What is latent heat? |
| The energy that is absorbed or released during the phase change of a substance. |
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| What is 1 cal? |
| 1 cal is the amount of heat required to raise the temperature of 1 g of water by 1°C. |
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| What is convection? |
| Convection is the process of heat transfer due to movement of molecules in fluid. |
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| What is radiation? |
| Radiation is the process of heat transfer through electromagnetic waves. |
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| What is conduction? |
| The process of Heat transfer due to vibration of atoms. |
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| What type of lens is used in Newton's Rings Experiment |
| Plano Convex lens is used in Newton's Rings Experiment |
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| Why circular rings are formed? |
| Circular rings are formed because of the same thickness of air between the lens and glass plate. |
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| What if we increase the wavelength of light? |
| Since diameter of ring is directly proportional to wavelength , diameter of ring will increase. |
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| What is Newton's ring? |
| The phenomenon in which a interference pattern is created due to reflection from spherical surface and glass plate. |
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| What is interference? |
| Phenomenon in which two coherent sources are combined. |
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| What is function of 45 degree glass plate? |
| It turns the light rays coming from extended source to 90 degrees so te rays will fall normally on Plano Convex lens. |
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| Types of interference? |
| Constructive and destructive interference. |
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| What is fraunhoffer diffraction? |
| Fraunhoffer diffraction occurs when a plane wavefront is incident on the slit. |
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| What is Fresnel diffraction? |
| Fresnel diffraction occurs when the light source is at finite distance from the slit. |
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| What is diffraction? |
| The slight bending of light as it passes through edge of an object. |
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| What is interference? |
| The phenomenon in which two or more waves superimpose to form a resultant wave. |
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| What is grating element? |
| Grating element is the distance between two consecutive slits. |
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| What is the use of collimeter? |
| Collimeter is used to obtain a plain wavefront. |
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| What is the use of telescope? |
| Telescope is used to converge the light. |
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| What is diffraction grating? |
| It is a glass plate ruled with parallel lines which produce spectrum on diffraction. |
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| Types of wavefront |
| Spherical wavefront, plane wavefront, cylindrical wavefront. |
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| What is spectrum? |
| Band of colours when a white light splits. |
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| Which light scatters the most? |
| Red light , bcoz it has smaller wavelength. |
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| What is coherence length? |
| Coherence length is the space over which the wave is sinusoidal. |
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| What is temporal coherence? |
| If we consider two points in propagation of wave and phase difference between these points is constant then it is said to be temporal coherence. |
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| What is Diffraction? |
| The slight bending of light when it passes through edge of the object is called diffraction. |
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| What is spontaneous Emission? |
| When an atom in ground state absorbs certain amount of energy and goes to higher state and then falls back and then emits photon. This process is called spontaneous Emission. |
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| What is Stimulated emission? |
| The emission of electromagnetic radiation in the form of photons triggered by photons of same frequency. |
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| Properties of a laser? |
| Bright coherent monochromatic unidirectional |
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| How does he ne laser work? |
| The hene mixture is exposed to radio frequency voltage . He absorbs energy and gets excited. It interacts with the neon atoms and transfer their energy. These neon atoms give stimulated radiations. |
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| What is wedge shape? |
| It is a shape in which two inclined planes are joined together to form a sharp edge. |
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| Why are fringes straight? |
| The fringes are straight because the thickness of air is constant over a straight line along the width of the wedge. |
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| What will happen if we white light? |
| Coloured fringes will be formed. |
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| What is fringes width? |
| Fringe width is the distance between two consecutive bright or dark fringes. |
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| Why we use glass plate inclined? |
| It turns the light rays by 90° so that the rays will fall normally on the slit. |
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| What is threshold frequency? |
| The minimum frequency of incident radiation for photoelectron emission to take place. |
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| Stopping potential? |
| The potential at which the current flow through the circuit stops |
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| Saturation current? |
| The maximum value of photoelectric current is called as saturation current |
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| What is thermal conductivity? |
| Thermal conductivity is the property of the material that indicates the ability of the material to conduct heat. |
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| Unit of thermal conductivity? |
| W / mk |
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| Why is disc circular? |
| To avoid loss of heat or for even heat distribution. |
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| Why can't it be used for good conductors? |
| Bcoz the temperatures T1 and T2 would be almost same. |
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| Why steam is used? |
| Because steam carries more heat than water. |
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| Thermal conductivity depends upon what? |
| rate of heat transfer, temperature, surface area |
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| H = kA(T2 - T1) / x What is H? |
| H is the steady state rate of heat transfer |
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| What is photoelectric effect? |
| Emission of electrons when electromagnetic radiation hits the metal surface. |
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| What is stopping potential? |
| The potential at which the current through the circuit stops. |
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| What is threshold frequency? |
| Minimum frequency of incident radiation for photoelectron emission to take place. |
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| What is threshold wavelength? |
| Minimum wavelength of incident radiation for photoelectron emission to take place. |
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| What is work function? |
| Minimum energy of incident radiation for photoelectron emission to take place. |
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| Significance of planks constant? |
| To find work function of metal.It tells us relation between energy and frequency.It tells the energy of 1 quanta.Energy of 1 quanta = hv |
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| What is Saturation current? |
| The maximum value of photoelectric current. |
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| What is reverse bias? |
| In reverse bias the reverse voltage slows down the flow of electrons and finally stops them. |
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| Full form of CRO? |
| Cathode ray Oscilloscope |
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| What is CRO? |
| Fullform of CRO is Cathode ray Oscilloscope. It gives visual representation of electrical quantities like voltage, current, etc. |
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| How are cathode rays produced? |
| Cathode rays are produced when the electrons hit the fluorescent screen. |
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| What are the types of waveform? |
| Types of waveform are triangular, square and sine waveform. |
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| What is time-base circuit? |
| Time base circuit is used to produce sawtooth waveforms. |
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| What is sawtooth waveforms? |
| It is type of wave in which the voltage varies linearly with time and then drops and cycle continues. |
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| Applications of CRO |
| CRO is used to measure current, voltage, frequency, resistance, impedence, admittance, power Factor. |
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| What are channels? |
| Channels are used to compare different waveforms. There are two channels. |
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| What is blanking circuit? |
| Blanking ckt is used to change the potential between the cathode and the screen grid of the cathode Ray tube. |
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| State malus law |
| Malus law states that the intensity of plane polarized light that passes through analyser varies as the square of consine of the angle between axis of of polariser and analyser. |
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| What is polarization? |
| Polarization is the process which causes light to vibrate in single plane. |
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| What is Polaroid? |
| Polarid is a material which polarizes light. |
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| What is polarizer? |
| Polarizer is an optical device which converts unpolarized light to polarized light. |
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| What is analyser? |
| Analyser is an optical device which checks whether the light is polarized. |
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| Types of polarisation |
| Linear circular elliptical |
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| What is Atom Economy? |
| Atom economy is how many atoms are incorporated into the products and how many wasted. |
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| Difference between esterification and transesterification? |
| Esterification is used to produce esters while transesterification is used to modify esters during chemical reaction. |
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| Synthesis of Biodiesel from Vegetable oil |
| Triglycerides can be easily broken down into glycerol and fatty acids this is called as transesterification to produce Biodiesel. |
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| What is Nebulizer |
| it breaks up the sample into atoms |
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| Proximate Analysis |
| proximate Analysis gives approximate composition of components in the coal. |
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| Ultimate Analysis |
| proximate Analysis gives approximate composition of components in the coal. |
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| Moisture content |
| it controls the rate of combustion. |
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| Volatile matter |
| it helps in initial combustion. |
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| Ash content |
| higher is the Ash content lower is the calorific value of coal. |
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