Pair Production | MCQs

Explanation

Pair production occurs when a high-energy γ-ray photon is converted into an electron and a positron near a nucleus.

It is a quantum phenomenon that requires photon energy greater than 1.022 MeV.

Explanation

Given:

Energy of photon (E) = 4.1 MeV

The total energy available for the electron and positron is:

E - 2 × 0.511 MeV = 4.1 MeV - 1.022 MeV = 3.078 MeV

Since the electron and positron share the energy equally, the kinetic energy of the electron is:

3.078 MeV / 2 = 1.539 MeV

Adding the rest mass energy of the electron (0.511 MeV), we get:

Energy of electron = 1.539 MeV + 0.511 MeV = 2.05 MeV

Explanation

In pair production, several quantities are conserved

Let's evaluate each option:

- Charge:

A charge is conserved in pair production, as the total charge before and after the interaction remains the same

Due to the opposite but equal charges of the electron and positron.

- Energy:

Energy is conserved in pair production, with the total energy before the interaction equal to the sum of the energies of the electron and positron after the interaction.

- Linear Momentum:

Linear momentum is conserved in pair production, with the total momentum before the interaction equal to the sum of the momenta of the particles involved.