First slide

Coherent sources and their importance in interference

Question

Two beams of light having intensities I and 4I interfere to produce a fringe pattern on a screen. The phase difference between the beams is $\frac{π}{2}$ at point A and $π$ at point B. Then, the difference between resultant intensities at A and B is

Moderate

A

5I
B

4I
C

3I
D

7I

Solution

$I (ϕ) = I_{1} + I_{2} + 2 \sqrt{I_{1} I_{2}} \cos ϕ H e r e, I_{1} = I a n d I_{2} = 4 I A t p o i n t A, ϕ = \frac{π}{2} ∴ I_{A} = I + 4 I + 0 = 5 I A t p o i n t B, ϕ = π ∴ I_{B} = I + 4 I - 4 I = I h e n c e . I_{A} - I_{B} = 4 I$

Get Instant Solutions

When in doubt download our app. Now available Google Play Store- Doubts App

Recieve an sms with download link

Doubts App

OR

SCAN ME

Doubts App

Doubts App