Question

In an $X$ ray tube the electrons are expected to strike the target with a velocity that is $10$% of the velocity of light. The applied voltage should be:

• A. $517.6V$
• B. $1052V$
• C. $2.559kV$
• D. $5.680kV$

Answer 1

The correct option is C $2.559kV$

Velocity, $v=10$

Now, $\frac{1}{2}m{v}^2=E=\frac{hc}{\lambda }=eV\to \frac{1}{2}m{v}^2=eV\to V=\frac{1}{2}\frac{m{v}^2}{e}=\frac{9.1\times {10}^{-31}\times 9\times {10}^{14}}{2\times 1.6\times {10}^{-19}}=2559.375=2.559kV$