The direction of drift velocity in a conductor is :

Options

A. opposite to that of applied electric field
B. opposite to the flow of positive charge
C. in the direction of the flow of electrons
D. All of these

Answer

To determine the direction of drift velocity in a conductor, we need to analyze the behavior of charge carriers (electrons) when an electric field is applied.

### Step-by-Step Solution:

1. **Understanding Drift Velocity**:
- Drift velocity is the average velocity that charge carriers (like electrons) acquire due to an electric field applied across a conductor.

2. **Applying Electric Field**:
- When a potential difference is applied across a conductor (for example, by connecting it to a battery), an electric field is established within the conductor.
- The direction of the electric field is from the positive terminal (higher potential) to the negative terminal (lower potential).

3. **Behavior of Positive and Negative Charges**:
- Positive charges (like holes) will move in the direction of the electric field because they experience a force in that direction.
- Electrons, being negatively charged, will experience a force in the opposite direction of the electric field. Therefore, they will move opposite to the direction of the electric field.

4. **Direction of Drift Velocity**:
- Since drift velocity is defined as the average velocity of the charge carriers, and electrons are the primary charge carriers in conductors, the drift velocity of electrons will be in the opposite direction to the electric field.
- Consequently, the drift velocity is also opposite to the direction of flow of positive charge.

5. **Conclusion**:
- Therefore, the drift velocity in a conductor is opposite to the applied electric field, opposite to the flow of positive charge, and in the direction of the flow of electrons.
- The correct answer is that the direction of drift velocity is "all of these".

### Final Answer:
The direction of drift velocity in a conductor is: **All of these**.

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