COMEDK2015PhysicsWave Optics
Two coherent monochromatic light beams of intensities I and 4 I are superimposed. The maximum and minimum possible resulting intensities are
Options
- A5 I and 0
- B5 I and 3 I
- C9 I and I
- D9Iand 3 I
Correct answer
C. 9 I and I
Step-by-step solution
Intensities of two monochromatic sources, I₁=I and I₂=4 I Maximum intensity, aligned I_ &= ( I₁ + I₂ )² &=I₁+I₂+2 I₁ I₂ &=I+4 I+2 I 4 I =9 I aligned Minimum intensity, aligned I_ &= ( I₁ - I₂ )² &=I₁+I₂-2 I₁ I₂ &=I+4 I-2 I 4 I &=5 I-4 I=I aligned