Explain the production of X-rays with a labelled diagram of the tube. Distinguish between continuous and characteristic X-rays and state any three properties of X-rays.

1. 1 · Define in one line. X-rays come out when a heavy metal target brings very fast electrons to a sudden stop.
2. 2 · Explain the working. A heated filament gives electrons; a high voltage accelerates them in a highly evacuated tube; they strike a tungsten target; cooling water removes the heat.
3. 3 · Draw the tube. [Diagram: evacuated glass tube, filament F with low-voltage supply, slanted target with cooling water, high-voltage source, electron arrows, X-ray beam]
4. 4 · Give the two types.
   • Continuous: all wavelengths above λmin; λmin = hc/eV depends on the voltage
   • Characteristic: sharp lines fixed by the target element (Moseley's law)
5. 5 · State three properties. They blacken photographic plates, ionise gases and are not deflected by electric or magnetic fields.
6. 6 · Real life. Hospitals use X-rays to see broken bones; airports use them to scan baggage.
7. 7 · Close in one line. So, the current controls how many X-rays, and the voltage controls how penetrating they are.

Scoring tip: Label the filament, target, high voltage, cooling and X-rays on the diagram. Write the Duane-Hunt formula under the continuous type.