Question

If the angle between incident beam and crystallographic plane is ${30}^{\circ }$, then the scattering angle is -

• A. ${125}^{\circ }$
• B. ${115}^{\circ }$
• C. ${110}^{\circ }$
• D. ${120}^{\circ }$

Answer 1

The correct option is D ${120}^{\circ }$

Given:

$\varphi ={30}^{\circ }$

In the below figure, $\theta$ is the scattering angle and $\varphi$ is the angle between incident beam and crystallographic plane.



From figure,

$2\varphi +\theta ={180}^{\circ }$

$\Rightarrow \theta ={180}^{\circ }-2\times {30}^{\circ }={120}^{\circ }$

Hence, option $\left(D\right)$ is the correct answer.