An X-ray tube operates at 50 kV with a tube current of 4.0 mA. Only 1.0% of the electrical power delivered to the electron beam appears as X-ray radiation; the rest is converted mainly into heat in the target. If the X-ray power is N watts, find N.
Physics · Atomic Structure and X-rays · x-rays and its types
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Question

An X-ray tube operates at 50 kV with a tube current of 4.0 mA. Only 1.0% of the electrical power delivered to the electron beam appears as X-ray radiation; the rest is converted mainly into heat in the target. If the X-ray power is N watts, find N.

Physics · Atomic Structure and X-rays · x-rays and its types

G1 Physics · Accepted Answer

Electrical power supplied to the electron beam is P(input) = VI. Substitute: P(input) = 50,000×4.0×10⁻³ = 200 W. Only 1.0% becomes X-rays: P(X-ray) = 0.01×200 = 2 W. Therefore N = 2.