Two coherent source of light,whose intensity ratio is 49:1 produces interference fringe.Calculate the ratio of intensity of maximum and minimum in the fringe system.

Explanation

Let `I_(1)` and `I_2` be the intensity of light from the two coherent sources.
`I_(1)/I_(2) = 49/1`
`sqrt(I_(1)/I_(2)) = sqrt(49/1) = 7`
`I_("maxi")/I_("mini") = (sqrt(I_(1)/I_(2))+1)^(2)/ (sqrt(I_(1)/I_(2))-1)^(2) =(7+1)^(2)/(7-1)^(2)`
`=(8)^(2)/(6)^(2)`
`I_("maxi")/I_("mini") = 64/36 = 16/9`
= 16 : 9