The number of electrons emitted by a surface exposed to light is directly proportional to

Options

A. Frequency of light
B. Work function of metal
C. Threshold wave length
D. Intensity of light

Answer

To solve the question regarding the number of electrons emitted by a surface exposed to light, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Photoelectric Effect**:
The photoelectric effect is a phenomenon where electrons are emitted from a material (usually a metal) when it is exposed to light of sufficient frequency.

2. **Identifying Key Factors**:
The number of electrons emitted depends on several factors, including the intensity of the incident light and the frequency of the light.

3. **Intensity of Light**:
The intensity of light is defined as the power per unit area. In the context of the photoelectric effect, higher intensity means more photons are striking the surface per unit time.

4. **Proportionality**:
According to the principles of the photoelectric effect, the number of photoelectrons emitted is directly proportional to the intensity of the incident light. This is because more photons (which carry energy) lead to more electrons being emitted, provided the frequency of the light is above the threshold frequency for the material.

5. **Conclusion**:
Therefore, we conclude that the number of electrons emitted by a surface exposed to light is directly proportional to the intensity of that incident light.

### Final Answer:
The number of electrons emitted by a surface exposed to light is directly proportional to the intensity of the incident light.

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