Operating at 40 kV , an X-ray tube has an electric current of 10 mA flowing from the target to the filament. Assuming that, on average, 1 % of the total kinetic energy of the electrons striking the target is converted into X-rays, determine the total power emitted as X-rays.

Step-by-step solution

The total electrical power supplied to the X-ray tube is given by P_ in = VI . Substituting the given values: P_ in = 40 10^3 10 10⁻³ = 400 W This is the total kinetic energy of the electrons striking the target per second. Since 1 % of this energy is converted into X-rays, the total power emitted as X-rays is: P_ X = 1 100 P_ in P_ X = 1 100 400 = 4 W