Question

Two coherent monochromatic light beams of intensities 4/ and 9/ are superimosed the maxmum and minimum possible intenties in the resulting beam are
A. 3I and 2I
B. 9I and 5I
C. 16I and 3I
D. 25I and I

Answer 1

Correct Answer - a
Here `I_(1)=4I` and `I_(2)=9I`
`=4I+9I+2sqrt(4Ixx9I)`
`=13I+2xx6I=13I+12I rarr I_(max)=25I`
and `I_(min)=I_(1)+I_(2)-2sqrt(1_(1(I_(2)))-2sqrt(I_(1)I_(2)=4I+9)-2sqrt(4Ixx9I)`
`=13I-2xx6I=13I-12I rarr I_(min)=I`