JIPMER2013PhysicsWaves and Sound
Two coherent light beams of intensities I and 4 I are superposed. The maximum and minimum possible intensities in the resulting beam are
Options
- A5 I and I
- B5 I and 3 I
- C9 I and I
- D9 I and 3 I
Correct answer
C. 9 I and I
Step-by-step solution
The net intensity due to interference of two beams of intensities ( I ₁, I ₂ ) with a phase difference of ( ) is ( I _ net = I ₁+ I ₂+2 I ₁ I ₂ ) Thus, ( I _ net _ max ) occurs for ( =1 ) ( I _ net _ = ( I ₁ + I ₂ )^2=9 I ) Similarly, ( I _ net _ ) occurs for ( =-1 ) ( I _ net _ = ( I ₁ - I ₂ )^2= I )