Answer the following questions.
What is piece of iron inside a wire coil.called.

Explanation

To answer the question, "What is a piece of iron inside a wire coil called?" we can follow these steps:

### Step 1: Understand the Components
- A wire coil is made of conductive material (usually copper) that can carry electric current.
- When a piece of iron is placed inside this coil, it interacts with the magnetic field created by the electric current flowing through the wire.

### Step 2: Identify the Function
- The combination of the wire coil and the piece of iron enhances the magnetic field produced by the coil. This is because iron is a ferromagnetic material, which means it can be magnetized and will strengthen the magnetic field.
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