An X-ray tube is operating at 50 kV and 20 mA. The target material of the tube has a mass of 1.0 kg and specific heat 495 J kg⁻¹ °C⁻¹. One percent of the supplied electric power is converted into X-rays and entire remaining energy goes into heating the target. Then:
Select all that apply

Question

An X-ray tube is operating at 50 kV and 20 mA. The target material of the tube has a mass of 1.0 kg and specific heat 495 J kg⁻¹ °C⁻¹. One percent of the supplied electric power is converted into X-rays and entire remaining energy goes into heating the target. Then:

Select all that apply

G1 Physics · Accepted Answer

Input power=50 kV×20 mA=1000 W. Heating power=0.99×1000=990 W, so rate of temperature rise=990/(1×495)=2 °C s⁻¹ (A). λₘᵢₙ=hc/eV≈0.248 Å=0.25×10⁻¹⁰ m (B). A target should have high melting point and high thermal conductivity, so C and D are false. Correct: A, B.