question_answer

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)  \[n\lambda =2\theta \sin \theta \]

Correct Answer: A

Solution :

                  When a beam of monochromatic X-ray strikes two planes of atom in a crystal at a certain angle 9, it is reflected. Intensity of the reflected beam is maximum if\[n\lambda =2d\,\sin \theta \] This is called Braggs equation,    where, \[n=\] order of reflection (1, 2,3... etc.)\[\lambda =\] wavelength of X-ray light used \[d=\] distance between two planes