Q. Two coherent sources of intensity ratio 1:4 produce an interference pattern. The fringe visibility will be
A) 1
B) 0.8
C) 0.4
D) 0.6
Explanation
(b) $\frac{I_{1}}{I_{2}} = \frac{1}{4} \Rightarrow I_{1} = k$ and $I_{2} = 4k$
$\therefore$ Fringe visibility $V = \frac{2\sqrt{I_{1}I_{2}}}{(I_{1} + I_{2})} = \frac{2\sqrt{k \times 4k}}{(k + 4k)} = 0.8$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.