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:
- Einstein’s photoelectric equation states:\[K_{\text{max}} = h f - \phi\]Here, \( h \) is Planck’s constant, \( f \) is the incident light frequency, and \( \phi \) is the material's work function.
- The photoelectric effect shows: - No electrons are emitted if the incident light's frequency \( f \) is below a threshold frequency \( f_0 \).
- Electron kinetic energy increases as frequency surpasses \( f_0 \).
- Light intensity influences the quantity of emitted electrons, not their kinetic energy.
Therefore, the photoelectric effect demonstrates light's quantum nature by establishing a minimum threshold frequency for electron emission.