Direction Read the following question choose if: (a) Both Assertion and Reason are true and Reason is correct explanation of Assertion. (b) Both Assertion and Reason are true, but Reason is not correct explanation of Assertion. (c) Assertion is true but the Reason is false. (d) Both Assertion and Reason is false. Assertion: Photo-electric effect can take place only when frequency is greater than threshold frequency \(\left(f_{0}\right)\) Reason: Electron is Fermions and photon is boson. (A) a (B) \(b\) (C) \(\mathrm{c}\) (D) d

The assertion states that the photoelectric effect can only take place when the frequency of light is greater than the threshold frequency \(\left(f_{0}\right)\). This is true, as the photoelectric effect occurs when the energy of the incident light (or photons) is sufficient to free electrons from the surface of a material. And according to Planck's quantum theory, the energy of a photon is proportional to its frequency, which means that only when the frequency is above the threshold value can the photoelectric effect take place.

The reason provided claims that electrons are fermions and photons are bosons. This is also true. Fermions are particles that follow the Pauli Exclusion Principle and have half-integer values for their quantum state. Electrons are fermions. On the other hand, bosons are particles that have whole-integer values for their quantum state and can occupy the same quantum state simultaneously. Photons are bosons.

While both the assertion and reason are true statements, they do not have a direct connection. The reason provided explains the classification of electrons and photons, but it does not directly explain the relationship between the frequency of light and the occurrence of the photoelectric effect. The threshold frequency is related to the energy levels of electrons in the material and the energy of the incident photons, but it is not related to whether electrons and photons are fermions or bosons. Since both the assertion and reason are true but the reason does not have a direct connection with the assertion, the correct answer is: (b) Both Assertion and Reason are true, but Reason is not the correct explanation for Assertion.