MCQ
Two coherent sources $P$ and $Q$ produce interference at point $A$ on the screen where there is a dark band which is formed between $4^{\text {th }}$ bright band and $5^{\text {th }}$ bright band. Wavelength of light used is $6000 \hat{A}$. The path difference between $P A$ and $Q A$ is
- A$1.4 \times 10^{-4} cm$
- B$2.7 \times 10^{-4} cm$
- C$4.5 \times 10^{-4} cm$
- D$6.2 \times 10^{-4} cm$
