When a gas is introduced between the pole-pieces of a magnet, it spreads at right angles to the magnetic field. The gas is

Options

A. paramagnetic
B. ferromagnetic
C. Diamagnetic
D. non-magnetic

Answer

To solve the question regarding the behavior of gas when introduced between the pole pieces of a magnet, we can analyze the situation step by step.

### Step-by-Step Solution:

1. **Understanding the Magnetic Field**:
- A magnet creates a magnetic field around it, which has a specific direction from the north pole to the south pole. This field influences charged particles and certain materials.

**Hint**: Remember that magnetic fields have both direction and magnitude, and they can affect the motion of charged particles.

2. **Introducing the Gas**:
- When a gas is introduced between the pole pieces of a magnet, we need to consider the nature of the gas. Gases are typically made up of neutral particles, but they can become ionized or have charged particles under certain conditions.

**Hint**: Think about how gases behave in the presence of magnetic fields, especially in terms of their charge and motion.

3. **Behavior of the Gas**:
- The question states that the gas spreads at right angles to the magnetic field. This behavior is indicative of the Lorentz force, which acts on charged particles moving in a magnetic field. The force is perpendicular to both the velocity of the particles and the magnetic field direction.

**Hint**: Recall the right-hand rule for the Lorentz force, which helps determine the direction of the force acting on a charged particle in a magnetic field.

4. **Conclusion on the Nature of the Gas**:
- Since the gas spreads at right angles to the magnetic field, it suggests that the gas contains charged particles or ions that are affected by the magnetic field. This behavior is characteristic of a plasma or ionized gas.

**Hint**: Consider what types of gases can be ionized and how they would behave in a magnetic field.

### Final Answer:
The gas is likely to be an ionized gas or plasma, as it spreads at right angles to the magnetic field due to the influence of the Lorentz force acting on charged particles.