A conductor in the form of a circular loop is carrying current I. The direction of the current is as shown. Then which figure represents the correct direction of magnetic field lines on the surfaces of the planes XY and XZ. (Consider those surfaces of the XY and XZ planes which are seen in the figure.)

Options

A.
B.
C.
D.

Explanation

To determine the correct direction of the magnetic field lines on the surfaces of the XY and XZ planes due to a current-carrying circular loop, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Configuration**: We have a circular loop carrying a current \( I \). The loop lies in a plane, and we need to analyze the magnetic field in the XY and XZ planes.

2. **Apply the Right-Hand Thumb Rule**: The right-hand thumb rule states that if you curl the fingers of your right hand in the direction of the current flow, your thumb will point in the direction of the magnetic field inside the loop.

3. **Determine the Magnetic Field Direction in the XY Plane**:
- When we look at the XY plane from above the loop (assuming the current flows in a clockwise direction), the magnetic field lines will circulate around the loop.
- According to the right-hand rule, if the current is flowing clockwise, the magnetic field lines in the XY plane will also be directed downwards (into the plane).

4. **Determine the Magnetic Field Direction in the XZ Plane**:
- Now, consider the XZ plane. If we visualize the loop from the side, the current flowing in the loop creates a magnetic field that circulates around the loop.
- Using the right-hand rule again, if the current is flowing clockwise when viewed from above, the magnetic field lines in the XZ plane will circulate in an anticlockwise direction.

5. **Conclusion**:
- In the XY plane, the magnetic field lines are directed downwards (clockwise).
- In the XZ plane, the magnetic field lines are directed upwards (anticlockwise).

### Final Answer:
- The correct representation of the magnetic field lines is that in the XY plane they are clockwise and in the XZ plane they are anticlockwise.