The interference pattern is obtained with two coherent light sources of intensity ratio n. In the interference patten, the ratio `(I_(max)-I_(min))/(I_(max)+I_(min))` will be

Explanation

KEY IDEA
Calculation: Given `I_(1) // I_(2) = n`, therefore, the amplitude ratio is
`(A_(1))/(A_(2))=sqrt(n)`
Also, `I_("max")=A_(1)+A_(2)` and `I_("min")=A_(1)+A_(2)`, Therefore,
`(I_("max")-I_("min"))/(I_("max")+I_("min"))=((A_(1)+A_(2))^(2)-(A_(1)-A_(2))^(2))/((A_(1)+A_(2))^(2)+(A_(1)-A_(2))^(2))`
`=(2A_(1)A_(2))/(A_(1)^(2)+A_(2)^(2))`
`=(2A_(1) // A_(2))/((A_(1)^(2) // A_(2)^(2))+1)=(2sqrt(n))/(n+1)`