Physical Optics MCQs
Multiple choice questions.
1.) Such a surface on which all the points have the same phase of vibration is known as ,
a) wave front.
b) front plane
c) back plane.
d) wave phase
Ans : a) wave front
2.) A line normal to the wave front, showing the direction of propagation of light is called,
a)wave of light.
b) ray of light
c) wave of beem.
d) ray of frequency
Ans : b) ray of light
3.) In Young’s double slit experiment the bright fringes are terned as
a)maxima.
b) minima
c) equal.
d) zero
Ans : a) maxima
4.) In Young’s double slit experiment the dark fringes are terned as
a)maxima.
b) minima
c) equal.
d) zero
Ans : b) minima
5.) The property of bending of light around obstacles and spreading of light waves into the geometrical shadow of an obstacles is called
a) diffraction.
b) ray of light
c) wave front.
d) phase
Ans : a) diffraction
6.) The distance between two consecutive wave fronts is called.
a) wave distance. b) phase
c) ray of light. d) wavelength
Ans : d) wavelength
7.) All points on a primary wavefront can be considered as the source of secondary wavelets, it is
a) Huygens principle. b) Young’s double slit experiment
c) Newton’s law. d) Planck’s law
Ans : a) Huygens principle
8.) When two or more waves overlap each other there is a resultant wave. This phenomenon is called
a) wave distance. b) interference
c) ray of light. d) wavelength
Ans : b) interference
9.) In case of destructive interference the amplitude of the resulting wave is _______ either of the individual waves.
a) greater than. b) less than
c) equally. d) more than one
Ans : b) less than
10). Complete the formula of Young’s double slit experiment for bright fringe, dsinθ = _______
a)mλ.
b)(m+½)
c)(m+½)λ.
d) mλ/2
Ans : a) mλ
11). Complete the formula of Young’s double slit experiment for dark fringe, dsinθ = _______
a)mλ.
b)(m+½)
c)(m+½)λ.
d) mλ/2
Ans : c)(m+½)λ
12.) In Young’s double slit experiment, the distance between two adjacent bright or dark fringes is , ∆y = _______
a)Lλ/d.
b) λ/Ld
c) dλ/L.
d) Ld/λ
Ans : a) Lλ/d
13.) ________ rings are circular fringes formed due to interference in a thin air film enclosed between a convex lens and a flat glass plate.
a) Planks. b) Newton’s
c) Michelsons. d) Young’s
Ans : b) Newtons
14.) Michaelsons interometer is used for very precise ______ measurements.
a) weight. b) pressure
c) length. d) time
Ans : c) length
15.) In Michelsons interremeter the distance L of the moving mirror when m fringes moves in view is
a)mλ/t.
b) mλ/2
c) 2m/λ.
d) λt/m
Ans : b) mλ/2
16) Bending of light around obstacles is due to ______ of light.
a) reflection. b) refraction
c) deflection. d) difraction
Ans : c) deflection
17.) Complete the formula of diffraction grating, where n stands for nth order of maxima.
dsinθ = _______
a)nλ b) nλ/2
c) n²λ d) n/λ
Ans : a) nλ
18.) Complete the formula of difraction of x – rays by crystals, where n is the order of reflection.
2dsinθ = _______
a)nλ/2 b) nλ
c) n²λ d) n/λ
Ans : b) nλ
19.) ______ of the light proves that light consists of transverse electromagnetic waves.
a) Polarization. b) Magnifiacation
c) electrification. d) difraction
Ans : a) Polarization