On heating a ferromagnetic substance above curie temperature

Options

A. becomes paramagnetic
B. becomes diamagnetic
C. remains ferromagnetic with constant magnetic susceptibility
D. becomes electromagnetic

Explanation

**Step-by-Step Solution:**

1. **Understanding Curie Temperature**:
- Curie temperature (Tc) is a critical temperature for ferromagnetic materials. Below this temperature, the material exhibits ferromagnetism, which means it can be magnetized and retains its magnetic properties even when the external magnetic field is removed.

2. **Behavior Above Curie Temperature**:
- When a ferromagnetic substance is heated above its Curie temperature, the thermal energy overcomes the magnetic ordering of the material. This leads to a change in the magnetic properties of the substance.

3. **Transition to Paramagnetism**:
- Above the Curie temperature, the material loses its ferromagnetic properties and transitions to a paramagnetic state. In this state, the material can still be magnetized, but it does not retain any magnetization once the external magnetic field is removed.

4. **Conclusion**:
- Therefore, when a ferromagnetic substance is heated above its Curie temperature, it becomes paramagnetic.

**Final Answer**: The ferromagnetic substance becomes paramagnetic when heated above the Curie temperature.

---