R4RIN – MCQs, Mock Tests | CBES Board Class 12 CBES Board(Class 12-Physics)MCQ Questions with Answers(Chapter 10 Wave Optics)

The idea of secondary wavelets for the. propagation of a wave was first given by

1. Newton
2. Huygens
3. Maxwell
4. Fresnel

✅ Correct Answer: 2

Light propagates rectilinearly, due to

1. wave nature
2. wavelengths
3. velocity
4. frequency

✅ Correct Answer: 1

Which of the following is correct for light diverging from a point source?

1. The intensity decreases in proportion with the distance squared.
2. The wavefront is parabolic.
3. The intensity at the wavelength does not depend on the distance.
4. None of these.

✅ Correct Answer: 1

The refractive index of glass is 1.5 for light waves of X = 6000 A in vacuum. Its wavelength in glass is

1. 2000 Å
2. 4000 Å
3. 1000 Å
4. 3000 Å

✅ Correct Answer: 2

The phenomena which is not explained by Huygen’s construction of wavefront

1. reflection
2. diffraction
3. refraction
4. origin of spectra

✅ Correct Answer: 4

A laser beam is used for locating distant objects because

1. it is monochromatic
2. it is not chromatic
3. it is not observed
4. it has small angular spread.

✅ Correct Answer: 4

Two slits in Young’s double slit experiment have widths in the ratio 81 :1. The ratio of the amplitudes of light waves is

1. 1/0/1900 3:01
2. 1/0/1900 3:02
3. 1/0/1900 9:01
4. 1/0/1900 6:01

✅ Correct Answer: 3

When interference of light takes place

1. energy is created in the region of maximum intensity
2. energy is destroyed in the region of maximum intensity
3. Conservation of energy holds good and energy is distrubuted
4. Conservation of energy does not hold good

✅ Correct Answer: 3

To observe diffraction, the size of the obstacle

1. should beX/2, where X is the wavelength.
2. should be of the order of wavelength.
3. has no relation to wavelength.
4. should be much larger than the wavelength.

✅ Correct Answer: 2

The velocity of light in air is 3 * 108 ms-1 and that in water is 2.2 * 108 ms” . The polarising angle of incidence is

1. 45°
2. 50°
3. 53.74°
4. 63

✅ Correct Answer: 3

An optically active compound

1. rotates the plane of polarised light
2. changes the direction of polarised light
3. does not allow plane polarised light to pass through
4. none of these

✅ Correct Answer: 1