Electric Potential And Potential Difference

The electric potential at any point due to a point charge is given by: where is the charge and is the distance from the charge. Since points R and S are equidistant from the two charges and , the potential at these points due to each charge will be the same. Therefore, the net potential at both points will be equal, and as a result, the work done in moving the charge from point R to point S will be zero, since work is given by , and . Final Answer: (A) Zero

Concept: The electric field is related to electric potential by: Force on a charge: Thus, the magnitude of force depends on the slope of the vs graph.

Steeper slope larger electric field
Flat region zero force

Step 1: Analyze each point. At P: The graph is horizontal (constant potential). At Q: The graph has a moderate negative slope. This means a finite electric field and moderate force. At R: Again, the graph is flat (constant potential). At S: The graph rises very steeply (large positive slope). Since electric field magnitude depends on slope: Thus, the force magnitude is maximum at S.
Step 2: Conclusion. Maximum force occurs where the potential changes most rapidly with position. This happens at point S.