X-ray is the reverse process of:

Explanation

Option A: Pair production is a process in which a photon interacts with a nucleus or an electron and produces an electron-positron pair. This process typically occurs at very high energies, such as those found in high-energy particle collisions. It is not the reverse process of X-ray interactions.Option B: Compton Effect: In Compton scattering, the high energy photon strikes the material which causes transfer of some of its energy to the outer shell electron. The result of which is the production of photons with lower energy than the incident photon and the free electron. Thus, in Compton Effect both photons and electrons cause knockout of the material by the incident photon. Therefore, option B is Option C: We know that when the high energy electrons strike a heavier material, the high energy electrons are deflected by the nuclei of the material. In this process, there is a deceleration of the electrons which causes them to emit the photons. Thus, in the process of production of continuous X-ray, high energy electrons are used to emit photons. The reverse process of this is the emission of electrons when the photons strike on the material. In the photoelectric effect, the photon having the energy greater than the work function of the material when it strikes the material, the electron gets knocked out from the inner shell of the atom. Thus, we can say that it is the reverse process of production of continuous X-ray. Therefore, the option C is correct. Note: In photoelectric effect, the inner shell electron gets knocked out from the atom because the energy of the photon is greater than the work function of the material whereas in Compton Effect, both electron and photon are knocked out from the atom but the electron getting knocked out is the outer shell electron. There is another term known as par production. But in pair production, the photon is converted into two antiparticles: electron and positron. Option D: This option implies that both pair production and the Compton effect are reverse processes of X-ray interactions. However, only the Compton effect is the correct answer. Pair production is not the reverse process of X-ray interactions but rather a different phenomenon occurring at much higher energies.