When a plastic rod is rubbed with wool, it acquires a negative charge because

Options

A. Electrons are removed from it
B. Electrons are added to it
C. Protons are removed from it
D. Protons are added to it

Answer

To solve the question of why a plastic rod acquires a negative charge when rubbed with wool, we can break down the explanation into clear steps:

### Step-by-Step Solution:

1. **Understanding the Materials**:
- Identify the two materials involved: a plastic rod and wool.

2. **Friction and Charge Transfer**:
- When the plastic rod is rubbed against the wool, friction occurs between the two materials. This friction causes a transfer of charge.

3. **Work Function Concept**:
- The work function is the minimum energy needed to remove an electron from an atom. In this case, the work function of wool is lower than that of the plastic rod.

4. **Movement of Electrons**:
- Due to the friction, electrons from the wool are able to overcome the work function and move to the plastic rod.

5. **Resulting Charge on the Rod**:
- As the plastic rod gains electrons, it accumulates an excess of negative charge. This is because electrons are negatively charged particles.

6. **Conclusion**:
- Therefore, the plastic rod acquires a negative charge because electrons are added to it from the wool.

### Final Answer:
The correct answer is: **Electrons are added to it.**

---