Question

Braggs law is given by the equation

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