Optics Question 160
Question: Two point sources X and Y emit waves of same frequency and speed but Y lags in phase behind X by 2pl radian. If there is a maximum in direction D the distance XO using n as an integer is given by
Options:
A) $ \frac{\lambda }{2}(n-l) $
B) $ \lambda (n+l) $
C) $ \frac{\lambda }{2}(n+l) $
D) $ \lambda (n-l) $
Show Answer
Answer:
Correct Answer: B
Solution:
For maxima $ 2\pi n=\frac{2\pi }{\lambda }(XO)-2\pi l $
or $ \frac{2\pi }{\lambda }(XO)=2\pi (n+l) $ or $ (XO)=\lambda (n+l) $