Question

The quantum nature of light explains the observations on the photoelectric effect as:

• A. There is a minimum frequency of incident radiation below which no electrons are emitted.
• B. The maximum kinetic energy of photoelectrons depends only on the frequency of incident radiation.
• C. When the metal surface is illuminated, electrons are ejected from the surface after some time.
• D. The photoelectric current is independent of the intensity of incident radiation.

Hint:

The photoelectric effect provided crucial evidence for the particle nature of light, leading to the development of quantum mechanics.

Answer 1

The Correct Option is A

Explanation of the Photoelectric Effect:
- According to Einstein’s photoelectric equation: \[ K_{\text{max}} = h f - \phi \] where \( h \) is Planck’s constant, \( f \) is the frequency of incident light, and \( \phi \) is the work function of the material.
- The photoelectric effect demonstrates that:
- If the frequency \( f \) of the incident light is less than a threshold frequency \( f_0 \), no electrons are emitted.
- Increasing the frequency above \( f_0 \) increases the kinetic energy of emitted electrons.
- The intensity of light affects the number of electrons emitted, but not their kinetic energy.
Thus, the correct explanation for the quantum nature of light in the photoelectric effect is that there exists a minimum threshold frequency below which no electrons are emitted.