Choose the correct statement regarding the photoelectric effect ?

Options

A. Photocurrent reverses its direction when the applied voltage is reduced further below the stopping potential
B. The photocurrent varies linearly with the applied voltage
C. The stopping potential remains unaffected by the intensity of the incident light.
D. Saturation currect remains unaffected by the intensity of incident light.

Answer

To solve the question regarding the photoelectric effect, let's analyze each of the provided statements one by one:

**Step 1: Analyze Statement A**
- Statement A: "Photoelectric current reverses its direction when the applied voltage is reduced further below the stopping potential."
- Explanation: The stopping potential is the maximum voltage needed to stop the photoelectric current. If the applied voltage is reduced below this stopping potential, the current does not reverse direction; it simply stops. Thus, this statement is incorrect.

**Step 2: Analyze Statement B**
- Statement B: "The photo current varies linearly with the applied voltage."
- Explanation: The photoelectric current increases with the applied voltage up to a certain point, but it does not vary linearly throughout the entire range. Once saturation current is reached, increasing the voltage further does not increase the current. Therefore, this statement is also incorrect.

**Step 3: Analyze Statement C**
- Statement C: "The stopping potential remains unaffected by the intensity of the incident light."
- Explanation: The stopping potential depends on the frequency of the incident light, not its intensity. Increasing the intensity increases the number of emitted electrons (and thus the current) but does not affect the stopping potential. This statement is correct.

**Step 4: Analyze Statement D**
- Statement D: "Saturation current remains unaffected by the intensity of the incident light."
- Explanation: The saturation current is directly related to the intensity of the incident light. As the intensity increases, the number of emitted electrons increases, leading to a higher saturation current. Thus, this statement is incorrect.

**Conclusion:**
After analyzing all the statements, the correct answer is:
- **C. The stopping potential remains unaffected by the intensity of the incident light.**