Two coherent sources of intensity ratio `9 : 4` produce interference. The intensity ratio of maxima and minima of the interference pattern is

Options

A. `13:5`
B. `5:1`
C. `25:1`
D. `3:2`

Answer

c

Explanation

`I_(max)/I_(min)=(sqrt(I_(1))+sqrt(I_(2)))^(2)/ (sqrt(I_(1))-sqrt(I_(2)))^(2)`
`= ( sqrt(I_(1)/ sqrt(I_(2))+1))^(2)/ ( sqrt(I_(1)/ sqrt(I_(2)) - 1))^(2)`
`=(3/2 +1)^(2)/(3/2 -1)^(2)`
` therefore I_(max):I_(min)=25:1`