Optics Question 233
Question: The width of the nth HPZ will be
Options:
A) $ \sqrt{nb\lambda } $
B) $ \sqrt{b\lambda }[\sqrt{n}-\sqrt{n-1}] $
C) $ (\sqrt{n}-\sqrt{n-1}) $
D) $ \frac{\sqrt{b\lambda }}{[\sqrt{n}-\sqrt{n-1}]} $
Show Answer
Answer:
Correct Answer: B
Solution:
Width of nth HPZ $ B _{n}=r _{n}-{r _{n-1}} $
$ r _{n}=\sqrt{nb\lambda } $ , $ {r _{n-1}}=\sqrt{(n-1)b\lambda } $
$ B _{n}=\sqrt{nb\lambda }-\sqrt{(n-1)b\lambda }=\sqrt{b\lambda }[\sqrt{n}-\sqrt{(n-1)}] $
