Description : What is true for intensity of scattered light according to Rayleigh's law? A. The intensity for scattering for light of largest wavelength more B. The light of smallest wavelength will be scattered ... C. All the wavelengths are scattered equally D. Intensity of light is not affected by scattering
Last Answer : B. The light of smallest wavelength will be scattered more
Description : In the Tyndall Effect, the intensity of scattered radiation is inversely proportional to the fourth power of the wavelength. Which one of the following colors of light would exhibit the most intense Tyndall scattering? w) yellow x) green y) orange z) violet
Last Answer : ANSWER: Z -- VIOLET
Description : A thin film having thickness t
Last Answer : (c) Black
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 : 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 : To observe interference in thin films with a light of wavelength λ, the thickness of the film (a) Should be much smaller than λ (b) Should be a few thousand times of λ (c) Should be of the order of λ (d) Should be of the order of nanometer
Last Answer : (c) Should be of the order of λ
Last Answer : C. Black
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 : Resolving power of grating is given by A. λ/2 B. λ/dλ C. dλ/λ D. none of these
Last Answer : B. λ/dλ
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 : Optical fiber works on the A. principle of refraction B. total internal reflection C. scattering D. interference
Last Answer : B. total internal reflection
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 reference with antireflection coating which of the following statement is true? A. Thickness of the film should be changed for light of same wavelength but different intensity B. Thickness of ... D. Thickness of the film should be decreased for light of same wavelength but higher intensity
Last Answer : B. Thickness of the film need not be changed for light of same wavelength but different intensity
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 : Loss due to the diffraction of light when it strikes on the irregularities formed during the manufacturing process of the fiber optics. A. Absorption loss B. Attenuation C. Bending loss D. Rayleigh scattering loss
Last Answer : D. Rayleigh scattering loss
Description : It is caused by the difference in the propagation time of light rays that take different paths down the fiber. ∙ A. modal dispersion ∙ B. microbending ∙ C. Rayleigh scattering ∙ D. chromatic dispersion
Last Answer : A. modal dispersion
Description : he Radius (or diameter) of bright rings in Newton's rings is (a) Directly proportional to the square root of odd numbers (b) Inversely proportional to the square root of natural numbers (c) ... to the square root of even numbers (d) Directly proportional to the square root of natural numbers
Last Answer : (a) Directly proportional to the square root of odd numbers
Description : In Newton's Ring experiments , the diameter of dark rings is proportional to A. Odd Natural numbers B. Natural Number C. Even Natural Number D. Square root of natural number
Last Answer : In Newton's Ring experiments , the diameter of dark rings is proportional to A. Odd Natural numbers B. Natural Number C. Even Natural Number D. Square root of natural number
Description : n Newton's Ring experiments , the diameter of bright rings is proportional to A. Square root of Odd Natural numbers B. Natural Number C. Even Natural Number D. Square root of natural number
Last Answer : B. Natural Number
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 : 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 : The sky appears blue due to – (1) Rayleigh scattering (2) Mie scattering (3) Back scattering (4) None of the above
Last Answer : (1) Rayleigh scattering Explanation: The blue colour of the sky is due to Rayleigh scattering. As light moves through the atmosphere, most of the longer wavelengths pass straight through. Little ... absorbed blue light is then radiated in different directions. It gets scattered all around the sky.
Description : The dominant loss mechanisms in silica fiber are ∙ a. Absorption and radiation losses ∙ b. Absorption and Rayleigh scattering ∙ c. Coupling and radiation losses ∙ d. Radiation and modal dispersion
Last Answer : b. Absorption and Rayleigh scattering
Description : The sky appears blue due to (1) Rayleigh scattering (2) Mie scattering (3) Back scattering (4) None of the above
Last Answer : Rayleigh scattering
Description : which of the following statements is not true for scattering of light? (a) Colour of the scattered tight depends on the size of particles of the atmosphere. (b) Red light is least scattered in the ... air scatter the blue, light more strongly than red. So the scattered blue light enters our eyes.
Last Answer : (c) Scattering of light Lakes place as various colours of white light travel with different speed in fir.
Description : The colour of scattered light depends on (a) Size of scattering particles (b) Wavelength of light (c) Both (a) and (b) (d) None of the above
Last Answer : (c) Both (a) and (b)
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 : 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
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 : Why in Newton's rings setup, the beam splitter (mirror) is kept at 450? (a) It allows light rays to incident at 450over the top surface of Plano convex lens (b) It allows light rays to ... Plano convex lens (d) It allows light rays to incident at 900over the top surface of Plano convex lens
Last Answer : (d) It allows light rays to incident at 900over the top surface of Plano convex lens
Description : Newton’s light illustrate the phenomenon of (a) Interference (b) Diffraction (c) Dispersion (d) Polarisation
Last Answer : (a) Interference
Description : In case of thin film of non-uniform thickness, when illuminated with white light, the film appears colored. This is due to change of what factor? (a) Conditions for path difference at different points of ... of film (c) Thickness of film is different at different points of film (d) All of above
Description : In Newton's rings experiment, if monochromatic source of light is replaced by another monochromatic source of higher wavelength. What will be the effect on radius (or diameter)? (a) Radius (or ... be no effect (d) Radius (or diameter) will remain constant but there will be more brightness
Last Answer : (b) Radius (or diameter) will increase
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 : 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 : 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
Last Answer : (d) Few colored bands and then general illumination
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) 2π (d) π/2
Last Answer : (b) π
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 : A film is said to be thin if its thickness is (a) Much smaller than wavelength of light (b) Comparable with one wavelength of light (c) Of the order of nanometer (10-9 m) (d) Of the order of Pico meter (10-12 m)
Last Answer : (b) Comparable with one wavelength of light
Description : The number of lines on plane gratings is 5000. If it is illuminated by a wavelength of light 6000 A0, how many orders will be visible? A. 3 B. 3.33 C. 4 D. 2.0
Last Answer : A. 3
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 : 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 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 : __________ of the following phenomenon cannot be explained on the particle nature of light. A. Photo Electric Effect B. Compton’s Effect C. Pair Production D. Interference
Last Answer : A. Photo Electric Effect
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 : 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 : .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 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 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