a vertical wall is in South north direction. a current carrying where is kept in the world such that to the west of the wall magnetic field due to wire is towards south then the wire where should be

Options

A. vertical and current in downwards
B. horizontal and current is toward West
C. vertical and current in upward
D. horizontal and current is towards east

Answer

To solve the problem, we need to determine the position of the current-carrying wire in relation to the vertical wall, given that the magnetic field due to the wire is directed towards the south when we are on the west side of the wall.

### Step-by-Step Solution:

1. **Understanding the Orientation**:
- The vertical wall is oriented in the South-North direction.
- The west side of the wall is to the left when facing north, and the east side is to the right.

2. **Magnetic Field Direction**:
- The problem states that the magnetic field due to the wire is directed towards the south when we are on the west side of the wall.

3. **Using the Right-Hand Rule**:
- To find the direction of the current in the wire, we can use the right-hand rule for magnetic fields created by current-carrying wires.
- According to the right-hand rule, if you point your thumb in the direction of the current, your fingers will curl in the direction of the magnetic field lines.

4. **Determining the Current Direction**:
- Since the magnetic field on the west side of the wall is directed towards the south, we need to position the wire such that the magnetic field lines produced by the current in the wire point south when observed from the west side.
- For the magnetic field to be directed south, the current must flow upwards (out of the wall) or downwards (into the wall) depending on the position of the wire.

5. **Final Position of the Wire**:
- If the wire is placed vertically in the wall and the current flows upwards, the magnetic field will circle around the wire in a counterclockwise direction (when viewed from above), which means that on the west side of the wall, the magnetic field will indeed point south.
- Therefore, the wire should be placed vertically in the wall with the current flowing upwards.

### Conclusion:
The current-carrying wire should be positioned vertically in the wall with the current flowing upwards.