Question

X-rays are produced when

• A. Electron beam strikes the nucleus of the atom
• B. Electron beam strikes the anode
• C. Electron beam reacts with the electromagnetic field
• D. Electron beam strikes the cathode

Hint:

Electrons are emitted from the cathode but X-rays are generated only when they slam into the anode target.

Answer 1

The Correct Option is B

Step 1: Recall the basic layout of an X-ray tube.
An X-ray tube has a heated cathode filament that emits electrons and an anode, or target, that these electrons are accelerated toward across a high voltage.

Step 2: Follow the electron's path.
Electrons boiled off the cathode filament are accelerated by the applied voltage and slam into the anode target, usually made of tungsten, at high speed.

Step 3: Explain what happens on impact.
When these fast electrons hit the anode, most of their energy turns into heat, but a small fraction produces X-rays in two ways. Bremsstrahlung radiation comes from electrons decelerating sharply as they pass near the strong electric field of target nuclei. Characteristic radiation comes from an incoming electron knocking out an inner shell electron of a target atom, with an outer shell electron then dropping down and releasing an X-ray photon of a set energy.

Step 4: Rule out the other options.
Electrons striking the nucleus directly does not happen in practice, and it is the deceleration near the nucleus, not a direct hit, that produces bremsstrahlung. There is no reaction between the electron beam and an external electromagnetic field involved in this process. The cathode is the source of electrons, not the target they strike, so X-rays are not produced there.

Step 5: Final answer.
\[ \boxed{\text{Electron beam strikes the anode}} \]