In the Davisson and Germer experiment , the velocity of electrons emitted from the electron gun can be increased by

Options

A. increasing the potential difference between the anode and filament
B. increasing the filament current
C. decreasing the filament current
D. decreasing the potential difference between the anode and filament

Answer

To solve the question regarding how to increase the velocity of electrons emitted from the electron gun in the Davisson and Germer experiment, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Experiment**: The Davisson and Germer experiment involves the emission of electrons from an electron gun, which are then directed towards a target. The velocity of these electrons is crucial for the experiment's outcomes.

2. **Identifying Key Variables**: The velocity of electrons can be influenced by the potential difference applied between the anode and the filament. This potential difference is what accelerates the electrons.

3. **Analyzing the Options**: We have four options to consider:
- A) Increasing the potential difference between the anode and filament.
- B) Increasing the filament current.
- C) Decreasing the filament current.
- D) Decreasing the potential difference between the anode and filament.

4. **Evaluating the Options**:
- **Option A**: Increasing the potential difference would increase the velocity of the electrons, as a higher potential difference means more energy is provided to the electrons.
- **Option B**: Increasing the filament current may increase the number of electrons emitted but does not necessarily increase their velocity.
- **Option C**: Decreasing the filament current would likely reduce the number of emitted electrons and does not help in increasing their velocity.
- **Option D**: Decreasing the potential difference would decrease the velocity of the electrons, which is contrary to what we want.

5. **Conclusion**: The correct answer is **Option A**: Increasing the potential difference between the anode and the filament will increase the velocity of the emitted electrons.

### Final Answer:
The velocity of electrons emitted from the electron gun in the Davisson and Germer experiment can be increased by **increasing the potential difference between the anode and the filament**.

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