A glass rod is rubbed with a silk cloth and inflated rubber balloon is rubbed with a woollen cloth.
Now , out of glass rod, silk cloth, rubber balloon and woollen cloth :
which two objects acquire negative charge ?

Explanation

To solve the question, we need to understand the process of charging by friction and the behavior of different materials when they are rubbed together.

### Step-by-Step Solution:

1. **Identify the Materials**: We have four objects: a glass rod, a silk cloth, an inflated rubber balloon, and a woolen cloth.

2. **Understand Charging by Friction**: When two different materials are rubbed against each other, one material can lose electrons and become positively charged, while the other material gains those electrons and becomes negatively charged.

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