Description : .If we narrow the distance between two slits in Young’s experiment the fringes width __________. A. Increases B. Decreases C. Remains same D. becomes zero
Last Answer : B. Decreases
Description : Diffraction due to circular aperture If a light passes through a small pinhole, and incident on a screen. What will be observed on the screen? A.A sharp bright point of the width equal to ... A bright ring at the centre surrounded by alternate dark and bright rings D. A diffused bright point
Last Answer : C. A bright ring at the centre surrounded by alternate dark and bright rings
Description : In Fraunhofer diffraction wave front used is __________. A. Spherical B. Circular C. Plane D. Conical 71.In diffraction pattern of monochromatic light the bright bands formed are __________. A. of uniform intensity B. of non-uniform intensity C. of uniform width D. is of different colors
Last Answer : A. of uniform intensity
Description : How the intensity of secondary maxima varies in case of Fraunhofer diffraction pattern for single slit? A. Intensity of secondary maxima decreases on either sides B. Intensity of ... C. Intensity increases and decreases alternately D. Intensity of secondary maxima increases on either sides
Last Answer : A. Intensity of secondary maxima decreases on either sides
Description : Which of the following condition is essential for observing Fraunhofer diffraction? A. Source must be close to slit and screen should be at infinite distance B. Both source and screen must be close to ... infinity and screen should be close to the slit D. Both source and screen must be at infinity
Last Answer : D. Both source and screen must be at infinity
Description : Fraunhofer diffraction at a Plane Grating What is the meaning of grating element for a diffraction grating? A It is the width of a single slit B. It is the width of the opaque space C. It is the distance between two slits D. It is the width of diffraction grating
Last Answer : C. It is the distance between two slits
Description : In Fresnel diffraction A. source of light is kept at infinite distance from the aperture B. source of light is kept at finite distance from the aperture C. Convex lens used D. aperture width is selected so that it can acts as a point source
Last Answer : B. source of light is kept at finite distance from the aperture
Description : What is the highest order spectrum which may be seen with monochromatic light of wavelength 5000 A0by means of diffraction grating with 5000 lines/cm? A. 2 B. 4 C. 8 D. 16
Last Answer : B. 4
Description : In plane transmission grating, the angle of diffraction for second order maxima for wavelength 5 x 10 -5 cm is 30 0. Calculate the number of lines in one centimeter of the grating surface. A. 1000 lines/cm B. 5000 lines/cm C. 500 lines/cm D. 10000 lines/cm
Last Answer : B. 5000 lines/cm
Description : To find prominent diffraction , the size of diffraction object should be A. greater than wavelength of light used B. comparable to order of wavelength of light C. less than wavelength of light used D. none of these.
Last Answer : B. comparable to order of wavelength of light
Description : Diffraction is special type of __________. A. Reflection B. Refraction C. Interference D. Polarization
Last Answer : B. Refraction
Description : here are two types of diffraction Fresnel and __________. A. Michelson B. De Broglie C. Fraunhofer D. Huygens
Last Answer : C. Fraunhofer
Description : X-ray diffraction can be observed by using __________. A. Diffraction Grating B. Rock salt crystal C. Convex lens D. Michelson’s interferometer
Last Answer : A. Diffraction Grating
Description : .The grating used to observe, diffraction of visible light can have approximately __________. A.300 lines per cm B.3000 lines per cm, C. 15000 lines per cm D. 30 lines per cm
Last Answer : C. 15000 lines per cm
Description : The diffraction observed by diffraction grating can also be Termed as __________. A. Single slit diffraction B. double slit Diffraction C. multiple Slit Diffraction D. Fresnel’s Diffraction
Last Answer : A. Single slit diffraction
Description : Fraunhofer diffraction is observed when __________. A. Only screen is placed at finite distance B. source is placed at finite distance C. neither source nor screen is at finite distance D. None of these
Last Answer : D. None of these
Description : Fresnel’s type diffraction is observed when __________. A. Only screen is placed at finite distance B. Only source is placed at finite distance C. Both source and screen are at finite distance D. Neither source nor screen is at finite distance
Last Answer : C. Both source and screen are at finite distance
Description : Newton’s light illustrate the phenomenon of (a) Interference (b) Diffraction (c) Dispersion (d) Polarisation
Last Answer : (a) Interference
Description : Which of the following phenomenon produces colors in soap bubble? (a) Interference (b) Diffraction (c) Polarization (d) Dispersion
Description : What is the effect of increasing the number of slits on the intensity of Central maxima of diffraction pattern of a diffraction grating? A. Intensity of central maxima will decrease B. Intensity ... maxima will increase C. There will not be any effect D. Diffraction pattern will disappear
Last Answer : B. Intensity of central maxima will increase
Description : The condition for minima in Fraunhofer diffraction for single slit is asinθ = mλWhat is ‘θ’? A. Angle of incidence of incident rays at the slit B. Angle at which diffracted rays strikes the screen C. Angle between slit and screen D. Angle of diffraction at which rays are diffracted at slit
Last Answer : D. Angle of diffraction at which rays are diffracted at slit
Description : In Fraunhofer diffraction pattern for single slit, a central maximum is obtained when angle of diffraction q is equal to zero. What it actually indicates? A. All the diffracted rays are parallel and focused ... are diffracted by the slit in all the directions D. The rays are reflected by the slit
Last Answer : A. All the diffracted rays are parallel and focused by slit at a single point on screen
Description : A diffraction grating is optically equivalent to a multiple slit system in which the number of slit , N is typically A.2000/cm B.3000/cm C.5000/cm D.1000/cm
Last Answer : C.5000/cm
Description : On a rainy day, small oil films on water show brilliant colors'. This is due to A. dispersion B. interference C. diffraction D. Polarization 49.The critical angle for a beam of light ... A. absorbed B. totally reflected C. Partially reflected and partially transmitted D. Totally transmitted
Last Answer : C. Partially reflected and partially transmitted
Description : Colors in thin films are because of A. Dispersion C. Interference B. Compton effect D. Diffraction
Last Answer : C. Interference
Description : Which of the following does not support the wave nature of light A. Interference C. Polarisation B. Compton effect D. Diffraction
Last Answer : B. Compton effec
Description : The wave nature of light is demonstrated by which of the following? A. The photoelectric effect B. Color C. The speed of light D. Diffraction
Last Answer : D. Diffraction
Description : significant diffraction of X ray can be obtained A. By a single slit B. By a double slit C. By diffraction D. By Atomic crystal
Last Answer : A. By a single slit
Description : In Fraunhofer diffraction, the incident wave front should be ….. A. elliptical B. Plane C. Spherical D. Cylindrical
Last Answer : B. Plane
Description : hat is the name of the process whereby waves travel around corners and obstacles in their paths? A. Reflection B. Refraction C Interference D. Diffraction
Description : The phenomenon of diffraction can be understood using A. Huygens principle B. Fraunhofer C. Uncertainty principle D. Fresnel
Last Answer : A. Huygens principle
Description : Interference pattern is observed in wedge-shaped film and bandwidth is noted. Now the angle of wedge is reduced to zero. What will be the effect on Bandwidth? (a) Bandwidth increases (b) Bandwidth decreases (c) Bands will disappear (d) There will not any effect
Last Answer : (c) Bands will disappear
Description : Interference pattern is observed in wedge-shaped film and bandwidth is noted. Now the angle of wedge is reduced. What will be the effect on bandwidth? (a) Bandwidth increases (b) Bandwidth decreases (c) Bands will disappear (d) There will not any effect
Last Answer : B) BANDWIDTH DECREASES
Description : Interference pattern is observed in wedge-shaped film and bandwidth is noted. Now the thin film is replaced by the film of higher refractive index. What will be the effect on bandwidth? (a) Bandwidth increases (b) Bandwidth decreases (c) Bands will merge (d) There will not any effect
Last Answer : (b) Bandwidth decreases
Description : When light passes from air into water, the frequency of the light remains the same. What happens to the speed? And the wavelength of light as it crosses the boundary in going from air into ... same Decreases C. Remains the same remains the same D. Decreases Increases E. Decreases Decreases
Last Answer : E. Decreases Decreases
Description : When Newton’s rings interference pattern is viewed from above by means of reflected light, the central spot is __________. A. Dark B. Multi colored C. Bright D. None of these
Last Answer : A. Dark
Description : .Fringe spacing is defined as the distance between two Consecutive __________. A. Crests B. Bright fringes only C. Dark fringes only D. Bright or dark fringes
Last Answer : A. Crests
Description : In Newton’s rings the central spot is __________. A. Always bright B. always dark C. can be bright or dark D. of blue color
Last Answer : C. can be bright or dark
Description : A thin film is observed in white light. The color of the film seen at a particular point depends upon (a)Location of observer (b)Width of the source (c) Distance of the source (d) Brightness of the source
Last Answer : (a)Location of observer
Description : The fringe width and the angle of wedge are related to A. β=λ/2θ B. θ =λ/2 β C. β=λ/θ D. λ= β/2θ
Last Answer : A. β=λ/2θ
Description : A slit of width ‘a’ is illuminated by white light. For what value of ‘a’ will the first minimum for red light fall at an angle of 300 wavelength of red light is 6500 A0 A. 1.1 x 10 -3 cm B. 1.4 X 10 -4 cm C. 1.3 X 10 -4 cm D. 1.6 X 10 -4 cm
Last Answer : C. 1.3 X 10 -4 cm
Description : If you look perpendicular at thin film and move yourself away from the film (staying perpendicular to the film), you will notice (a) Reflected light becomes brighter and brighter (b) Reflected ... and darker (c) Reflected light alternates between darker and brighter (d) None of the Above
Last Answer : (c) Reflected light alternates between darker and brighter
Description : In Newton’s rings experiment, if we reduce the radius of curvature of Plano Convex lens to zero, what will be effect on Newton’s rings? (a)They will become more bright (b)They will become more dark ( c)They will disappear (d) They will be more dense
Last Answer : ( c)They will disappear
Description : Interference pattern is observed in wedge-shaped film for monochromatic light. Now monochromatic light is replaced by white light. What will be the effect on interference pattern? (a) It will turn to dark (b) It will turn to bright (c) Bands will disappear (d) It will be a mixture of all colors
Last Answer : (d) It will be a mixture of all colors
Description : What is the nature of interference pattern at the contact edge of wedge shaped film (a) Always bright (b) Always dark (c) Bright or dark depending upon the thickness of other end (d) Bright or dark depending upon the wavelength of the light
Last Answer : (b) Always dark
Description : In interference experiment, by keeping all other parameters constant, if you see the thin film interference from different angles, you will observe (a)Uniform illumination of screen (b) Uniform ... c) Equally spaced dark and white bands (d) Few colored bands and then general illumination
Last Answer : (d) Few colored bands and then general illumination
Description : In interference experiment, monochromatic light is replaced by white light, we will see (a) Uniform illumination of screen (b) Uniform darkness on the screen (c) Equally spaced dark and white bands (d) Few colored bands and then general illumination
Description : Why in Newton’s rings the center spot is always dark? A. The thickness of the film is zero at center B. The path difference between incident ray and reflected ray is ½wavelength C. The incident ray and reflected ray undergo destructive interference D. All of above
Last Answer : D. All of above
Description : The points of constructive interference of light are__________. A. Always bright B. may be bright or dark C. always dark D. neither bright nor dark
Last Answer : A. Always bright
Description : In reflected light the central fringes of Newton's ring is A. dark B. Bright C. Uniform D. Non uniform
Last Answer : A. dark