Two coherent sources whose intensity ratio is 81:1 produce interference fringes. Calculate the ratio of intensity of maxima and minima in the fringe systen.

Explanation

Here `(I_(1))/(I_(2))=(a_(1)^(2))/(a_(2)^(2))=(16)/(1) implies (a_(1))/(a_(2))=(4)/(1)`,
where `a_(1)` and `a_(2)` are amplitudes of the waves from the two sources.
Now `(I_("max"))/(I_("min"))=((a_(1)+a_(2))^(2))/((a_(1)-a_(2))^(2)) =(((a_(1))/(a_(2))+1)^(2))/(((a_(1))/(a_(2))-1)^(2))`
`=(((4)/(1)+1)^(2))/(((4)/(1)-1)^(2))=(25)/(9)`