What happens when high-speed electrons strike the target in an x-ray tube?

When high-speed electrons strike the target in an x-ray tube, the primary outcome is the production of heat and radiation. This occurs because as the high-energy electrons collide with the target material (often tungsten), a significant portion of their kinetic energy is converted into thermal energy, which generates heat. This process is a result of inelastic collisions between the electrons and the atoms of the target material.

In addition to generating heat, a portion of the kinetic energy of the electrons is transformed into x-rays through a process known as Bremsstrahlung (or "braking radiation"). In this process, as electrons are decelerated by the nucleus of the target atoms, they lose energy, which is emitted as x-ray photons. Therefore, when electrons strike the target, both heat and ionizing radiation (x-rays) are produced, making this the correct answer.

The other options do not accurately describe the interactions occurring in an x-ray tube when electrons hit the target. The creation of a magnetic field does not occur as a direct result of this interaction, and the electrons do not simply disappear or convert to mechanical energy in the context of conventional x-ray tube operation. They transform their energy into heat and radiation instead.