List two ways of increasing the strength of an electromagnet if the material of the electromagnet is fixed.

Explanation

To increase the strength of an electromagnet while keeping the material fixed, we can follow these two methods:

### Step-by-Step Solution:

1. **Increase the Number of Turns of Wire:**
- The strength of the magnetic field produced by an electromagnet is directly proportional to the number of turns of wire wound around the core.
- Therefore, by increasing the number of turns (N), we can enhance the magnetic field strength (B). This means that if we wrap more coils of wire around the core, the electromagnet will become stronger.

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