Question

An x – ray tube operates at a d.c potential difference of 40 KV. Calculate the velocity of
the incident electrons. Assume charge – mass ratio of electron,
me
e
= 1.8 x 1011 C/kg.

Answer 1

$$0.5mv^2=eV$$

$$0.5v^2=(1.8\cdot10^{11})(40000)$$

$$v=1.2\cdot10^{8}\frac{m}{s}$$