Question

Five balls numbered 1,2,3,4,5 are suspended using reparate threads. The balls (1, 2), (2,4) and (4, I) show electrostatic attraction, while (2,3) and (4,5) show repulsion. Therefore, ball 1 must be

• A. negatively charged
• B. positively charged
• C. neutral
• D. made of metal

Answer 1

The correct option is C neutral

A charged body always attracts an uncharged body.

However repulsion means both the bodies have charge.

2 and 3 repel each other means they have the same charge.

Similarly 4 and 5 have same charge. But 2 and 4 attract each other means they have opposite charge.

In this condition only 2 cases are possible as shown in the diagram.

Please note the charges in both the cases.

Although 2 and 4 have opposite charges, 1 attracts 2 as well as 4 means it has to be neutral.