Two conductors A and B are joined by a copper wire. State the direction of flow of electrons in each of the following cases :

Explanation

To solve the problem of determining the direction of flow of electrons between two conductors A and B connected by a copper wire under different charge conditions, we can follow these steps:

### Step 1: Understand the Charge Conditions
We have three cases to analyze:
1. Case 1: Conductor A is positively charged and Conductor B is uncharged.
2. Case 2: Conductor A is negatively charged and Conductor B is uncharged.
3. Case 3: Conductor A is positively charged and Conductor B is negatively charged.

### Step 2: Analyze Each Case
**Case 1: A is positively charged and B is uncharged**
- Since A is positively charged, it has a higher electric potential compared to B, which is uncharged (considered to have zero potential).
- Electrons will flow from the region of lower potential (B) to the region of higher potential (A).
- **Direction of flow of electrons: B to A**

**Case 2: A is negatively charged and B is uncharged**
- Here, A has a lower electric potential (negative charge) compared to B (uncharged, zero potential).
- Electrons will flow from A (lower potential) to B (higher potential).
- **Direction of flow of electrons: A to B**

**Case 3: A is positively charged and B is negatively charged**
- In this case, A has a higher potential (positive charge) compared to B (negative charge).
- Electrons will flow from B (lower potential) to A (higher potential).
- **Direction of flow of electrons: B to A**

### Final Summary of Directions
1. Case 1: B to A
2. Case 2: A to B
3. Case 3: B to A