Dual Nature Of Light Question 384
Question: An X-ray tube with Cu target is operated at 25 kV. The glancing angle for a $ NaCl. $ Crystal for the $ Cu $ $ {K_{\alpha }} $ line is $ 15.8{}^\circ $ . Find the wavelength of this line. ( $ NaCl=2.82\overset{o}{\mathop{A}}, $ for, $ \text{h=6}\text{.62 }\times\text{ 1}{{0}^{-,27}}\text{erg-sec} $ )
Options:
A) 3.06 A
B) 1.53 A
C) 0.75 A
D) None of these
Show Answer
Answer:
Correct Answer: B
Solution:
[b] According to Bragg’s law, $ 2d\sin \theta =n\lambda $ , n = 1 for first order
$ \Rightarrow 2\times 2.82\sin 15.8=\lambda $
$ \Rightarrow \lambda =5.64\times 0.2723=1.53\overset{o}{\mathop{A}}, $
BETA
