Question

(b). Give the main two conditions for the occurrence of constructive interference in Bragg’s law with a suitable diagram.

Answer 1

As crystal tends to be bombarded with the X-rays of a fixed wavelength, and at respective incident angles, reflected intense X-rays tends to be produced if the of the scattered X-rays' wavelengths constructively interfere. So as waves interfere constructively, variations in travel path need to be similar to integer several wavelengths.