Mark out the correct statement regarding X-rays.

Options

A. When fast moving electrons strike the metal target, they enter the metal larged and in a very short time span come to rest , and thus an electromagnetic charged electron produces electromagnetic waves (X-ray).
B. Characteristic X-rays are produced due to transition of an electron from higher energy levels to vacant lower energy levels.
C. X-ray spectrum is a discrete spectra just like hydrogen spectra.
D. Both (a) and (b) are correct.

Answer

B

Explanation

Option (a) explains the production of X-ray on the basis of electromagnetic theory of light , which is not above to explain the characteristic X-ray and cut-off wavelength , so option (a) is wrong.
Option (b) correctly explain the production of characteri-stic X-ray.
Option ( c) is wrong as X-ray spectra is a continuous spectra having some peak representing characterstic x-rays.