What action does rubbing cause, because of which the objects acquire charge?

Explanation

### Step-by-Step Solution:

1. **Understanding Rubbing**: When two objects are rubbed against each other, they create friction. This friction is the primary action that leads to the charging of the objects.

2. **Friction and Heat Generation**: The friction between the two surfaces generates heat. This heat energy is crucial because it affects the electrons in the materials being rubbed.

3. **Energy Transfer to Electrons**: The heat generated provides energy to the electrons in the material. Electrons are negatively charged particles that can move from one atom to another.

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