In the Young's double slit experiment, the interference pattern is found to have as intensity ratio between the bright and dark fringes as 9. This implies that

Options

A. the intensities of individual sources are 5 and 4 units respectively
B. the intensities of individual sources are 4 and 1 units
C. the ratio of their amplitude is 3
D. the ratio of their amplitudes is 4

Answer

B

Explanation

Given, `I_("bright")/I_("dark")=I_(max)/I_(min)=9`
or `((a_(1)+a_(2))/(a_(1)-a_(2)))^(2)=9 or (a_(1)+a_(2))/(a_(1)-a_(2))=3`
`rArra_(1)/a_(2)=(3+1)/(3-1)rArra_(1)/a_(2)=2`
`So, I_(1)/I_(2)=a_(1)^(2)/a_(2)^(2)=4/1`