Question

At what angles for the first order diffraction, spacing between two planes respectively are $\lambda$ and $\frac{\lambda }{2}$ ?

• A. $0^{\circ },{90}^{\circ }$
• B. ${90}^{\circ },0^{\circ }$
• C. ${30}^{\circ },{90}^{\circ }$
• D. ${90}^{\circ },{30}^{\circ }$

Answer 1

The correct option is C ${30}^{\circ },{90}^{\circ }$

$n\lambda$ = 2d sin$\theta$, where
n = Order of reflection
$\lambda$ = wave length
$\theta$ = Angle of reflection
d = Inter planar distance