An X-ray tube operating at 20 kV produces heat at a rate of 200 W . Determine the current in the circuit, assuming that only a small fraction of the kinetic energy of the electrons is converted into X-rays.

Step-by-step solution

Since only a small fraction of the kinetic energy of the electrons is converted into X-rays, the rate of heat production is approximately equal to the total electrical power supplied to the tube. The electrical power is given by P = VI . Substituting the given values, P = 200 W and V = 20 kV = 20000 V : I = P V I = 200 20000 = 0.01 A