The magnetic lines of force around a current carrying straight conductor are in the form of .

Options

A. coaxial cylinders
B. concentric circles
C. parallel lines
D. concentric spheres

Answer

To answer the question about the magnetic lines of force around a current-carrying straight conductor, we can break down the solution into the following steps:

### Step-by-Step Solution:

1. **Understanding the Concept of Magnetic Field**:
- When an electric current flows through a conductor, it generates a magnetic field around it. This phenomenon is known as electromagnetism.

2. **Identifying the Shape of Magnetic Field Lines**:
- The magnetic field lines around a straight conductor are not random; they have a specific shape.

3. **Describing the Shape**:
- The magnetic field lines around a straight current-carrying conductor are in the form of concentric circles. This means that if you were to visualize the magnetic field lines, they would appear as circles centered around the conductor.

4. **Using the Right-Hand Thumb Rule**:
- To determine the direction of the magnetic field lines, you can use the right-hand thumb rule. According to this rule:
- Point your right thumb in the direction of the current flow.
- The direction in which your fingers curl around the conductor indicates the direction of the magnetic field lines.

5. **Visual Representation**:
- To better understand this concept, it is helpful to draw a diagram. In the diagram, you can illustrate a straight conductor with concentric circles around it, representing the magnetic field lines.

### Final Answer:
The magnetic lines of force around a current-carrying straight conductor are in the form of **concentric circles**.

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