Question

In Young’s double slit experiment, the ratio of maximum to minimum intensities of the fringe system is 4 :1. The amplitudes of the coherent sources are in the ratio:

• A. $4:1$
• B. $3:1$
• C. $2:1$
• D. $1:1$

Answer 1

The correct option is B $3:1$

Let the amplitude ratio be $x/y$
maximum to minimum intensity ratio is $(\frac{x+y}{x-y}{)}^2$
which is equal to $4/1$
$\frac{x+y}{x-y}=\frac{2}{1}$ Assuming $x$ is greater than y
$x+y=2x-2y$
$3y=x$
$\frac{x}{y}=3/1$