Five balls numbered 1 to 5 are suspended using separate threads. The pairs of balls (1, 2), (2, 4) and (5, 1) show attraction while the pairs (2, 3) and (4, 5) show repulsion. The ball 1 is :

Question

Five balls numbered 1 to 5 are suspended using separate threads. The pairs of balls (1, 2), (2, 4) and (5, 1) show attraction while the pairs (2, 3) and (4, 5) show repulsion. The ball 1 is : (A) positively charged (B) negatively charged (C) neutral (D) may be positively or negatively charged.

Tardigrade Admin · Accepted Answer

Here the charge on the balls 2 and 3 is similar. Also that on 5 and 4 is similar. But the balls 2 and 4 attract each other. Therefore, if the charge on ball 2 is +VE, then that on ball 5 must be -VE. But ball 1 is attracted both by the balls 2 as well as 5. This is possible only if ball 1 is neutral.

Q. Five balls numbered 1 to 5 are suspended using separate threads. The pairs of balls (1, 2), (2, 4) and (5, 1) show attraction while the pairs (2, 3) and (4, 5) show repulsion. The ball 1 is :

positively charged

negatively charged

neutral

may be positively or negatively charged.