Question

Braggs law is given by the equation

• A. $ n\lambda =2d\sin \theta $
• B. $ \lambda =2\,nd\sin \theta $
• C. $ 2n\,\lambda =d\sin \theta $
• D. $ n\lambda =2\theta \sin \theta $

Answer 1

Answer: (A)

When a beam of monochromatic X-ray strikes two planes of atom in a crystal at a certain angle $\theta$, it is reflected. Intensity of the reflected beam is maximum if
$n \lambda=2 d \sin \theta$
This is called Bragg's equation,
where, $n=$ order of reflection $(1,2,3$...etc. )
$\lambda=$ wavelength of X-ray light used
$d=$ distance between two planes