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

Options

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

Answer

C

Explanation

If ball 1 is neutral, ball 2 may be +, ball 3 may be +, ball 4 may be negative and ball 5 may be negative. This would satisfy the conditions of the question,