In a photoelectric experiment, if stopping potential is applied, then photocurrent becomes zero. This means that:

Options

A. the emission of photoelectrons is stopped
B. the photoelectrons are emitted but are reabsorbed by the emitter metal
C. the photoelectrons are accumulated near the collector plate
D. the photoelectrons are dispersed from the sides of the apparatus.

Answer

To solve the question regarding the photoelectric experiment and the effect of stopping potential on photocurrent, we can break down the explanation into clear steps:

### Step-by-Step Solution:

1. **Understanding Photoelectric Effect**:
- The photoelectric effect occurs when light of sufficient energy strikes a metal surface, causing the emission of electrons (photoelectrons) from that surface.

2. **Role of Stopping Potential**:
- Stopping potential is a negative voltage applied to the collector plate in a photoelectric experiment. Its purpose is to stop the emitted photoelectrons from reaching the collector.

3. **Effect of Stopping Potential on Photocurrent**:
- When the stopping potential is applied, it creates an electric field that opposes the motion of the photoelectrons towards the collector. If the stopping potential is strong enough, it will prevent all photoelectrons from reaching the collector.

4. **Resulting Photocurrent**:
- As a result of the stopping potential, the photocurrent (which is the flow of photoelectrons) becomes zero. This indicates that no electrons are able to reach the collector plate.

5. **Conclusion**:
- The zero photocurrent implies that the photoelectrons emitted from the emitter plate are either being stopped by the stopping potential or are being reabsorbed by the emitter plate.

6. **Correct Interpretation**:
- Thus, the correct conclusion is that the photoelectrons are emitted but are reabsorbed by the emitter metal due to the applied stopping potential.

### Final Answer:
The correct option is **B**: The photoelectrons are emitted but are reabsorbed by the emitter metal.

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