Two coherent light beams of intensity I and 41 are superposed. The maximum and minimum possible intensities in the resulting beam are

Options

A. 9I and I
B. 9I and 3I
C. 5I and I
D. 5I and 3I

Answer

a

Explanation

`a_(1)propsqrt1anda_(2)prop2sqrt1`
`:.I_(max)prop(a_(1)+a_(2))^(2)`
`:.I_(max)=(sqrtI+2sqrtI)^(2)=91`
`I_(min)prop(a_(2)-a_(1))^(2)`
`:.I_(min)=(2sqrtI-sqrtI)^(2)=I`