QUIZ ON WAVE OPTICS - MCQ WAVE OPTICS PART -1

1/10

The energy of the wave travels in a direction to the wavefront

Tangential

b. Parallel

c. Lateral

d. Perpendiculer

2/10

A light wave enters from air to glass. How will the velocity of wave be affected:

(a) increases

(b) remains unchanged

(c) decreases

(d) insignificant

3/10

2.The direction of wavefront of a wave with the wave motion is:

(a)parallel

(b)perpendicular

(c)opposite

(d)at an angle of θ

4/10

Which of the following phenomena’s are explained by Huygens’ Construction of Wave Front:

(a) reflection

(b) refraction

(c) both a&b

(d) none of these

5/10

Which of the following does not show any interference pattern?

a) Soap bubble

b) Excessively thin film

c) A thick film

d) Wedge Shaped film

Explanation: An excessively thin film shows no interference pattern because in that case, as the thickness of the film is negligible, the path difference, Δ, between the two reflected rays turns out to be λ/2 which is the condition of minima. Hence, the pattern is not observed.

6/10

What kind of sources are required for Young’s Double Slit experiment?

a) Coherent

b) Incoherent

c) Intense

d) Bright

Explanation: For the interference pattern to be visible, coherent sources are required.

7/10

If the distance between the two slits is doubled, the fringe width

a) Doubles

b) Halves

c) Four-times

d) Remains same

Explanation: The fringe width is inversely proportional to the distance between the two slits. As the distance between the slits doubles, the fringe width becomes half of its original value.

8/10

What change is observed when the whole pattern is immersed in water?

a) Fringe width decreases

b) Fringe width increases

c) Colored fringes

d) The bright and dark fringes will change

Explanation: When the whole apparatus of Young’s Double slit experiment is immersed in water, the only change is the pattern shrinks a bit. The width of the fringes decreases, as an external path difference is present because of the water.

9/10

A Young’s double slit apparatus is immersed in a liquid of refractive index 1.25. What is the ratio of the fringe width in air and liquid?

a) 1: 2

b) 4: 5

c) 5: 4

d) 2: 1

Explanation: In air, β = λaD/d In liquid, β’ = λlD/d , Now, β: β’ == λa: λl,= μ : 1 =5:4

10/10

Interference is observed only when the phase difference between the two waves is zero.

a) True

b) False

..

.

Explanation: For interference pattern, the phase difference between the two rays must be constant. It is not necessary that the phase difference between the two rays has to be zero.

Result: