Q. When a certain crystal was studied by the Bragg technique using X-rays of wavelength 229 pm, an X-ray reflection was observed at an angle of $23{^\circ}$ 20’. What is the corresponding interplanar spacing? $\left\lbrack \sin{\left( 23{^\circ}20^{'} \right) = 0.396} \right\rbrack$

A) 375.6 pm
B) 256.5 pm
C) 289.2 pm
D) 315.4 pm
Explanation

(c)
Given that,
$\lambda = 229\ pm\$and$\ \theta = 23{^\circ}20'$
Substituting these values in the Bragg’s equation, we have
$d_{hkl} = \frac{\lambda}{2\sin\theta} = \frac{229\ pm}{2\sin{(23{^\circ}20')}}$
$= \frac{229\ pm}{2 \times \ 0.396}$
= 289.2 pm

Dr. Abubacker
Reviewed by Dr. Abubacker

Physics Educator & NEET/JEE Specialist

Ph.D. in Physics with 19+ years of teaching experience.