Which device supplies power to accelerate electrons in the X-ray tube?

• A. Filament
• B. Anode
• C. High voltage transformer
• D. Power supply

Answer: (C)

The key idea is that electron acceleration in an X-ray tube comes from a large potential difference between the cathode (filament) and the anode. The filament heats up to emit electrons, but it doesn’t provide the accelerating energy. The anode needs to be at a high positive voltage to attract and accelerate those electrons, but the energy source that creates that high voltage is the high voltage transformer, which is part of the X-ray tube power supply. It steps up the mains power to the kilovolt range and, after rectification, delivers the high-voltage direct current across the tube.

So, the device that supplies the accelerating power is the high voltage transformer.