Ch 10. Wave Optics

Question 1

The concept of secondary wavelets was given by

Answer 1

Huygens

Question 2

The value of maximum amplitude produced due to interference two waves given by Y1 = 4sinωt and Y2 = 3 cosωt is

Y niche 1, ω (omega), Y niche 2

Answer 2

5

Question 3

The reason for the phenomenon of interference is

Answer 3

Phase Difference

Question 4

Which is used to produce polarised light?

Answer 4

Nicol prism

Question 5

The width of diffraction fringes is ………. to the width of interference fringes.

Answer 5

Unequal

Question 6

When the distance between source of light and screen is increased, then fringe width

Answer 6

Increases

Question 7

Light is a transverse wave because it shows

Answer 7

Polarization

Question 8

The wave front due to a point source at a finite distance from the source is

Answer 8

Spherical

Question 9

Interference of light is the redistribution of which of the following physical quantities?

Answer 9

Intensity

Question 10

Width of interference fringe is

Answer 10

β = λD/d

Question 11

The value of maximum amplitude produced due to interference of two waves is given by y₁ = 4 sin wt and y₂ = 3 cos wt

Answer 11

5

Question 12

The phase difference φ is related to path difference △x by

Answer 12

λ/2π φ

Question 13

Brewster’s law is

Answer 13

µ = tan ip

Question 14

The colour of a thin film is due to

Answer 14

Interference

Question 15

In the following question number 1 to 4, there are two column. Column 1 contains 4 questions. You have to match the correct options of these questions as A,B,C and D from column 2.

Answer 15

1. Brewster’s law = Polarisation
2. Liquid lens = Human eye
3. Chromatic Aberration = Defect of image
4. Young’s double slit experiment = Interference

Question 16

For the following question number 8 to 10 a paragraph is given. Read carefully the paragraph and select the correct answer out of given 4 options :

       Paragraph 

If two waves having amplitude A and B super imposes on each other and resultant amplitude is
A = √a² + b² + 2ab cosφ. where φ = phase constant. Intensity ( I ) is directly proportional to square of amplitude.
I ∝ A²
I ∝ (a² + b² + 2abcosφ)
In constructive interference I max = (a+b)²
In destructive interference I min = (a-b)²
Light waves from two coherent sources producing have intensity ratio 81 : 1.

Q. The ratio of maxima and minima in the interference pattern is

Answer 16

9 : 1

Question 17

The ratio of amplitude of light waves from two sources in

Answer 17

9 : 1

Question 18

For maximum intensity the value of cosθ is

Answer 18

+1