Question

Assertion (A): Photoelectric effect demonstrates the particle nature of light.
Reason (R): Photoelectric current is proportional to frequency of incident radiation.

• A. Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of the Assertion (A).
• B. Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of the Assertion (A).
• C. Assertion (A) is true, but Reason (R) is false.
• D. Assertion (A) is false and Reason (R) is also false.

Hint:

In the photoelectric effect, the frequency of the incident light determines whether photoelectrons are emitted, while the intensity determines the number of photoelectrons emitted. Therefore, the photoelectric current is proportional to intensity, not frequency.

Answer 1

The Correct Option is C

Analysis of Assertion (A): The photoelectric effect exemplifies the particle nature of light. This phenomenon involves light interacting with matter as discrete particles, known as photons, each possessing energy directly related to its frequency. This photon energy is transferred to electrons, enabling their emission from a material's surface, thereby confirming light's particle-like behavior. Analysis of Reason (R): The photoelectric current is not dependent on the frequency of the incident radiation. Instead, the current is directly proportional to the intensity of the incident radiation, which corresponds to the number of photons impacting the surface per unit time. While radiation frequency dictates the energy of emitted photoelectrons, it is the intensity, not the frequency, that governs the photoelectric current. Therefore, the statement in Reason (R) is inaccurate. Conclusion: Assertion (A) is accurate as the photoelectric effect validates the particle nature of light. Reason (R) is false because the photoelectric current is contingent upon the intensity, rather than the frequency, of the incident radiation.