Q. In $X$-ray tube when the accelerating voltage $V$ is halved, the difference between the wavelength of $K_{\alpha}$ line and minimum wavelength of continuous $X$-ray spectrum

A) Remains constant
B) Becomes more than two times
C) Becomes half
D) Becomes less than two times
Explanation

(d) $\mathrm{\Delta}\lambda = \lambda_{K_{\alpha}} - \lambda_{\min}$ When $V$ is halved $\lambda_{\min}$ becomes two time but $\lambda_{K_{\alpha}}$ remains the same.
$\therefore\mathrm{\Delta}\lambda^{'} = \lambda_{K_{\alpha}} - 2\lambda_{\min} = 2(\Delta\lambda) - \lambda_{K_{\alpha}}$
$\therefore\mathrm{\Delta}\lambda^{'} < 2(\Delta\lambda)$

Dr. Abubacker
Reviewed by Dr. Abubacker

Physics Educator & NEET/JEE Specialist

Ph.D. in Physics with 19+ years of teaching experience.