The charge acquired by a glass rod when it is rubbed with silk is:

Options

A. Negative
B. Positive
C. Both (A) and (B)
D. None of these

Answer

**Step-by-Step Solution:**

1. **Understanding the Materials**: When a glass rod is rubbed with silk, we need to identify the materials involved. Glass and silk are both insulators, but they interact differently when rubbed together.

2. **Charge Convention**: It is a convention in electrostatics that when certain materials are rubbed together, they acquire charges. In this case, the glass rod acquires a positive charge when rubbed with silk.

3. **Reasoning Behind Charge Acquisition**: The reason the glass rod becomes positively charged is due to the transfer of electrons. When the glass rod is rubbed with silk, electrons from the glass rod are transferred to the silk. This leaves the glass rod with a deficiency of electrons, resulting in a positive charge.

4. **Demonstrating Charge Interaction**: To further understand this, we can conduct a simple experiment. If we take a plastic straw and rub it with polythene, the straw will acquire a negative charge.

5. **Attraction of Opposite Charges**: When the positively charged glass rod is brought near the negatively charged plastic straw, they will attract each other. This attraction confirms that the glass rod has a positive charge and the plastic straw has a negative charge.

6. **Conclusion**: Therefore, the charge acquired by a glass rod when it is rubbed with silk is a positive charge.

**Final Answer**: The charge acquired by a glass rod when it is rubbed with silk is positive.

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