Question

In a Coolidge tube, the potential difference across the tube is 20 kV, and 10 mA current flows through the voltage supply. Only 0.5% of the energy carried by the electrons striking the target is converted into X-rays. The X-ray beam carries a
power of

• A. 0.1 W
• B. 1 W
• C. 2 W
• D. 10 W

Answer 1

The correct option is B 1 W

Power drawn by the coolidge tube $=(20\ast {10}^{3}V)(10\ast {10}^{-3}A)=200W.$

Power of X-ray beam $=\frac{0.5}{100}\ast 200W=1W.$