Description : When a light wave suffers reflection at the interface between air and glass medium, the change of phase of the reflected wave in air is equal to A. 0 B. π C.2 π D.π /2
Last Answer : B. π
Description : When a light wave suffers reflection at the interface between air and glass medium, the change of wavelength of the reflected wave in air is equal to (a) 0 (b) λ/2 (c) λ (d) 2λ
Last Answer : (b) λ/2
Description : When a light ray travelling in glass is incident on an air surface, A. it will refract away from the normal B. some of the light may be reflected C. all of the light may be reflected D. two of A, B, and C E. all of A, B, and C
Last Answer : E. all of A, B, and C
Description : When electromagnetic waves strike the boundary of denser medium they are __________. A. Reflected, in phase B. Reflected out of phase by 180° C. reflected, they are completely absorbed
Last Answer : B. Reflected out of phase by 180°
Description : Newton's rings are formed because of interference between the light Reflected from (a) Upper surface of Plano-convex lens and lower surface of plane glass plate (b) Lower surface of Plano-convex ... c) Lower and upper surface of Plano-convex (d) Lower and upper surfaces of plane glass plate
Last Answer : (b) Lower surface of Plano-convex lens and upper surface of plane glass plate
Description : Antireflection coating is helps in which case of the following? A. Minimizing the reflection of light from top surface B. To absorb and control the amount of light entering into the medium C. To allow maximum light to reflect from top surface D. To allow minimum light to enter into the medium
Last Answer : A. Minimizing the reflection of light from top surface
Description : An index of refraction less than one for a medium would imply A. That the speed of light in the medium is the same as the speed of light in vacuum B. That the speed of light in the ... greater than the speed of light in vacuum C. Refraction is not possible D. Reflection is not possible
Last Answer : B. That the speed of light in the medium is greater than the speed of light in vacuum
Description : The path difference corresponding to a phase difference of π radian is __________. A.2λ B .λ/2 C .λ /4 D. λ
Last Answer : B .λ/2
Description : The angle of incidence for a wave A. can be measured between the incident ray and the normal B. can be measured between the incident wave front and the boundary C. is equal to the angle of reflection D. all of the above
Last Answer : D. all of the above
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 : The interference in thin films is because (a) The film reflects some light (b) The film is thin enough so that refracted ray is close to reflected ray (c) The reflected ray undergo path change of λ/2 (d) All of above
Last Answer : (d) All of above
Description : Two sources of light are said to be coherent if __________. A. they produce waves of the same wave length B. they have the same amplitude of vibration C. they produce waves in the medium simultaneously D. they produce waves of the same amplitude
Last Answer : D. they produce waves of the same amplitude
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 : The phenomenon of Newton’s rings can be used to check the __________. A. Wavelength of monochromatic light B. phase coherence of two sources C. flatness of any glass surface D. velocity of light
Last Answer : A. Wavelength of monochromatic light
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 : 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 : In reflected light the central fringes of Newton's ring is A. dark B. Bright C. Uniform D. Non uniform
Last Answer : A. dark
Description : The speed of any mechanical wave as it propagates through a medium is dependent mainly on the A. frequency of the wave source B. wavelength C. period of the wave D. type of medium through which the wave travels E. amplitude
Last Answer : D. type of medium through which the wave travels
Description : .A beam of light is incident on a large block of glass. The index of refraction of the glass is greater than one. Is the wavelength of the light in the glass? A. Longer than B. Shorter than C. The same as the wavelength of the light in the air? D. None of above
Last Answer : B. Shorter than
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 : Critical speed of rotation, N (in rps - rotation per second) of a trammel is equal to (where, g = acceleration due to gravity = 9.81 m/sec 2 and, r = radius of trammel, metre.) (A) (1/2π). √(g/r) (B) (1/π). √(g/r) (C) ½ √(g/r) (D) 2π. √(g/r)
Last Answer : (A) (1/2π). √(g/r)
Description : 180° is equal to A. 2π rad B. π rad C. π⁄2 rad D. π⁄4 rad
Last Answer : π rad
Description : When a body moves with simple harmonic motion, the product of its periodic time and frequency is equal to A. Zero B. One C. π/2 D. 2π
Last Answer : B. One
Description : The conditions for the production of constructive and destructive interference are reversed due to the fact that on striking the thin film -------. A. Two rays of splitted light undergo phase ... two rays of splitted light undergo phase change of 180° C. Light is diffracted, light is polarized
Last Answer : A. Two rays of splitted light undergo phase change of 180°
Description : Coherent light of a single frequency passes through a double slit with a separation d, to produce a pattern on a screen as distance D from the slits. What would cause the separation between adjacent ... d between the slits C. increase the distance D. increase the frequency of the incident light
Last Answer : B. increase the separation d between the slits
Description : Light enters air from water. The angle of refraction will be A. Greater than the angle of incidence. B. Equal to the angle of incidence. C. Less than the angle of incidence. D. None of these
Last Answer : C. Less than the angle of incidence.
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 : 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 : .Light is A. an electromagnetic wave B. a form of energy visible to the human eye C. the same type of energy as an X ray D. the same type of energy as a radio wave E. all of the above
Last Answer : E. all of the above
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 : Interference of light is evidence that : A. The speed of light is very large B. light is a transverse wave C. light is electromagnetic in character D. Light is a wave phenomenon
Last Answer : D. Light is a wave phenomenon
Description : Light travels fastest A. In a vacuum B. through water C. Through glass D. through diamond
Last Answer : A. In a vacuum
Description : An Electromagnetic wave falls on to a boundary between two losses less homogeneous media with different refractive indices, a part of the wave is reflected back to the incident medium and the rest is transmitted ... A) Fresnel reflection (B) Fresnel refraction (C) Snell's law (D) None of these
Last Answer : Answer: Option A
Description : Diffraction is special type of __________. A. Reflection B. Refraction C. Interference D. Polarization
Last Answer : B. Refraction
Description : Optical fiber works on the A. principle of refraction B. total internal reflection C. scattering D. interference
Last Answer : B. total internal reflection
Description : The principle on which fiber optics is based is A. refraction C. polarization B. Dispersion. D. Total internal reflection
Last Answer : D. Total internal reflection
Description : Rainbow is due to A. absorption of sunlight in minute water droplets B. diffusion of sunlight through water droplets C. ionization of water deposits D. refraction and reflection of sunlight by water droplets
Last Answer : D. refraction and reflection of sunlight by water droplets
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 : A light ray travelling from denser to rarer medium at an angle of incidence more than critical angle of concerned media pair suffers. (1) reflection (2) refraction (3) diffraction (4) total internal reflection
Last Answer : (4) total internal reflection Explanation: If the angle of incidence of light ray in the denser medium is greater than the critical angle of the concerned media pair, the light is not at all reflected in to the rarer medium but is totally reflected. This is known as 'total internal reflection'.
Last Answer : total internal reflection
Description : In Michelson interferometer semi silvered mirror is used To obtain __________. A. Thin film interference B. Phase coherence C. mono chromatic light D. colored fringe
Last Answer : B. Phase coherence
Description : For spheres, volume shape factor is given by (A) π = (A/D2 ) (B) 2π = (2A/D2 ) (C) π/6 = (V/D3 ) (D) AD/V
Last Answer : (C) π/6 = (V/D3 )
Description : Critical Speed (Nc ) of a ball mill is given by (where R1 and R2 are radii of ball mill and the ball respectively). (A) Nc = (1/4π). √(g/R1 - R2 ) (B) Nc = (1/2π). √(g/R1 - R2 ) (C) Nc = (1/π). √(g/R1 - R2 ) (D) Nc = (1/2π). √(R1 - R2 /g)
Last Answer : (B) Nc = (1/2π). √(g/R1 - R2 )
Description : Power in watts in a shaft having N RPM is given by the equation (a) Power = 2π NT/60 (b) Power = 2π N T (c) Power = 2000 π N T/60 (d) None
Last Answer : (a) Power = 2π NT/60
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 : Interference in thin film is mainly because of (a) Division amplitude (b) Division of wave fronts (c) Addition of amplitude (d) Addition of wave fronts
Last Answer : (a) Division amplitude
Description : Interference in thin film is mainly because of A. Division amplitude B. Division of wave fronts C. Addition of amplitude D. Addition of wave fronts
Last Answer : A. Division amplitude
Description : .As a wave travels down a spring, the amplitude slowly decreases. Why does this occur? A. The law of conservation of energy does not apply to waves. B. The energy is spread out along the entire ... due to friction as the particles in the spring rub against each other. E. all of the above
Last Answer : D. Some energy is lost due to friction as the particles in the spring rub against each other.
Description : In Fraunhofer diffraction, the incident wave front should be ….. A. elliptical B. Plane C. Spherical D. Cylindrical
Last Answer : B. Plane
Description : Whose principle or law states that each point on a wave front may be considered a new wave source? Is it: A. Snell's Law B. Huygens’s Principle C. Young's Law D. Hertz's Law.
Last Answer : B. Huygens’s Principle