Question

A positively charged ball hangs from a silk thread. We put a positive test charge $q_0$ at a point and measure $\frac{F}{q_0}$, then it can be predicted that the electric field strength E.

• A. $>\frac{F}{q_0}$
• B. $=\frac{F}{q_0}$
• C. $<\frac{F}{q_0}$
• D. Cannot be estimated

Answer 1

The correct option is A $>\frac{F}{q_0}$

Because of the presence of positive test charge $q_0$ in front of positively charged ball, charge on the ball will be redistributed, less charge on the front half surface and more charge on the back half surface. As a result of this net force F between ball and point charge will decrease i.e. actual electric field will be greater than $\frac{F}{q_0}$