The correct option is (a).
Explanation
The interaction between charged objects is governed by the fundamental law of electrostatics: like charges repel each other, while unlike (opposite) charges attract each other. When objects are charged by friction (rubbing), the nature of the charge acquired depends on the material of the object and the material used for rubbing.
Statement-wise Analysis:
- Statement 1 is Correct: When two balloons are rubbed with the same material (e.g., a woolen cloth), they acquire the same type of electric charge. Since like charges repel, a charged balloon repels another charged balloon.
- Statement 2 is Incorrect: A charged refill (usually rubbed with polythene) and a charged balloon (usually rubbed with wool) acquire different types of charges. Since unlike charges attract, a charged balloon attracts a charged refill, rather than repelling it.
- Statement 3 is Incorrect: Similar to the case of the balloons, two refills rubbed with the same material acquire the same type of charge. Therefore, a charged refill repels another charged refill; it does not attract it.
Key Takeaway:
Objects carrying the same type of charge repel each other, whereas objects carrying different types of charges attract each other.