Question

Two sources of light P and Q have wavelengths 6000 Å and 5500 Å respectively. In a biprism experiment, first the source P is used, and then it is replaced by the source Q. it is found that the position of the `n^(th)` bright band corresponding to P is occupied by `(n+1)^(th)` bright band of Q. what is the value of n?
A. 5
B. 6
C. 10
D. 11

Answer 1

Correct Answer - D
`lambda_(1)= 6000Å, lambda_(2) 5500Å, n=?`
`n=(lambda_(2))/(lambda_(1)-lambda_(2))` Provided `lambda_(1) gt lambda_(2)`
` n=(5500)/(6000-5500)=11`