In an electric wire , the outer plastic case provides

Options

A. reflection
B. transparency
C. conduction
D. insulation

Explanation

**Step-by-Step Solution:**

1. **Understanding the Components of an Electric Wire:**
- An electric wire consists of a conductive core (usually made of copper or aluminum) that allows electric current to flow through it. Surrounding this core is an outer layer, often made of plastic or rubber.

2. **Identifying the Function of the Outer Layer:**
- The outer plastic case serves a specific purpose. It is important to determine what role this plastic layer plays in the context of electricity.

3. **Recognizing the Properties of Plastic:**
- Plastic is known to be an insulator. This means it does not conduct electricity. Insulators are materials that prevent the flow of electric current.

4. **Evaluating the Options Given:**
- The options provided are:
- Option 1: Reflection
- Option 2: Transparency
- Option 3: Conduction
- Option 4: Insulation
- Since we have established that the outer plastic case is an insulator, we can eliminate the other options.

5. **Conclusion:**
- The outer plastic case of an electric wire provides insulation. This insulation is crucial as it prevents electric shocks to users and protects the circuit from short circuits.

**Final Answer:**
The outer plastic case provides insulation.

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