Assertion: Soft iron is used as transformer core.
Reason: Soft iron has narrow hysteresis loop.

Options

A. If both assertion and reason are true and reason is the correct explanation of assertion.
B. If both assertion and reason are true and reason is not the correct explanation of assertion.
C. If assertion is ture but reason is false.
D. If both assertion and reason are false.

Answer

To analyze the assertion and reason provided in the question, we will break down the statements step by step.

### Step 1: Understanding the Assertion
**Assertion:** Soft iron is used as a transformer core.

- **Explanation:** Soft iron is widely used in transformer cores due to its properties. It has a high magnetic permeability, which means it can easily become magnetized and demagnetized. This property is essential for transformers, which need to efficiently transfer energy between coils through magnetic fields.

### Step 2: Understanding the Reason
**Reason:** Soft iron has a narrow hysteresis loop.

- **Explanation:** The hysteresis loop represents the relationship between the magnetizing force and the magnetic flux density in a material. A narrow hysteresis loop indicates that the material has low hysteresis loss. This means that when the magnetic field is cycled (as in a transformer), less energy is lost as heat due to magnetization and demagnetization. Soft iron indeed has a narrow hysteresis loop compared to other materials, which makes it suitable for use in transformers.

### Step 3: Evaluating the Relationship
- Both the assertion and the reason are true.
- The reason (soft iron has a narrow hysteresis loop) correctly explains why the assertion (soft iron is used as a transformer core) is true. The narrow hysteresis loop leads to low energy losses, making soft iron an ideal choice for transformer cores.

### Conclusion
Both the assertion and the reason are true, and the reason is a correct explanation of the assertion.

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