Chapter 16, Problem 18Q

Assume that the two opposite charges in Fig. 16-32a are 12.0 cm apart. Consider the magnitude of the electric field 2.5 cm from the positive charge. On which side of this charge—top, bottom, left, or right—is the electric field the strongest? The weakest? Explain.

To determine

Where the electric field is strongest and weakest from the positive charge.

Answer to Problem 18Q

Solution:

The electric field is strongest at $2.5$ cm away from the positive charge on its right side and is weakest at $2.5$ cm away from the positive charge on its left side.

Explanation of Solution

Since the electric field lines are more concentrated between the two charges, the electric field is strongest at $2.5$ cm away from the positive charge on its right side, that is in between the two charges. The field lines of positive charge are curling around towards the negative charge and hence the field lines are far apart on the left side of the positive charge. Therefore, the field is weakest at $2.5$ cm away from the positive charge on its left side.