Which of the following applications of plastics show(s) that plastics are bad conductors of electricity?
I. Refrigerators have an insulating wool of plastics.
II. Electric wires have a plastic coating.
III. Chemicals are stored in plastic containers.
IV. Parachutes are made from plastics.

Options

A. II, III and IV only
B. III and IV only
C. I only
D. II only

Answer

To determine which applications of plastics show that plastics are bad conductors of electricity, we will analyze each of the given statements one by one.

### Step-by-Step Solution:

1. **Statement I: Refrigerators have an insulating wool of plastics.**
- **Analysis:** The insulating wool in refrigerators is designed to prevent heat transfer. While plastics are indeed bad conductors of heat, this statement does not directly relate to their electrical conductivity. Therefore, this statement does not demonstrate that plastics are bad conductors of electricity.
- **Conclusion:** This statement is **incorrect**.

2. **Statement II: Electric wires have a plastic coating.**
- **Analysis:** The plastic coating on electric wires serves as insulation. This is because plastics are poor conductors of electricity, which helps to prevent electric shocks when touching the wires. Hence, this application clearly shows that plastics are bad conductors of electricity.
- **Conclusion:** This statement is **correct**.

3. **Statement III: Chemicals are stored in plastic containers.**
- **Analysis:** Chemicals are stored in plastic containers primarily due to the chemical resistance of plastics, not because of their electrical properties. This does not indicate that plastics are bad conductors of electricity.
- **Conclusion:** This statement is **incorrect**.

4. **Statement IV: Parachutes are made from plastics.**
- **Analysis:** Parachutes are typically made from materials like nylon, which is a type of synthetic fiber. While some parachutes may incorporate plastic components, the primary reason for using nylon is its strength and durability, not its electrical properties. Therefore, this does not demonstrate that plastics are bad conductors of electricity.
- **Conclusion:** This statement is **incorrect**.

### Final Answer:
The only correct application that shows plastics are bad conductors of electricity is **Statement II**: Electric wires have a plastic coating.