Magnetic lines of force due to a straight conductor carrying current are

Options

A. Straight lines
B. Elliptical
C. Circular
D. Parabolic

Answer

To determine the nature of magnetic lines of force due to a straight conductor carrying current, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Current in a Straight Conductor**:
- When an electric current flows through a straight conductor (like a wire), it generates a magnetic field around it.

2. **Applying the Right-Hand Thumb Rule**:
- To visualize the direction of the magnetic field, we can use the right-hand thumb rule. According to this rule, if you point your right thumb in the direction of the current flow, your fingers will curl around the wire in the direction of the magnetic field lines.

3. **Visualizing the Magnetic Field Lines**:
- As you apply the right-hand thumb rule, you will notice that the magnetic field lines form concentric circles around the straight conductor. This means that at any point around the wire, the magnetic field lines are perpendicular to the radius drawn from the wire to that point.

4. **Conclusion About the Nature of Magnetic Lines**:
- Since the magnetic field lines are circular and centered around the wire, we can conclude that the magnetic lines of force due to a straight conductor carrying current are circular in nature.

### Final Answer:
The magnetic lines of force due to a straight conductor carrying current are circular.

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