Question 76 of 311
Given below are two statements : one is labelled as Assertion (A) and the other is labelled as Reason(R)
Assertion (A) : Work done by electric field on moving a positive charge on an equipotential surface is always zero.
Reason (R) : Electric lines of forces are always perpendicular to equipotential surfaces.
In the light of the above statements, choose the most appropriate answer from the options given below :
Show answer and solution
Answer: (D) Both (A) and (R) are correct and (R) is the correct explanation of (A)
The equipotential surfaces are surfaces where the electric potential is the same at every point. In other words, there is no potential difference along an equipotential surface. Since work done is given by the equation , and there is no potential difference on an equipotential surface, the work done is always zero.
As there is no force along the surface of the equipotential surface, the electric field must be perpendicular to the surface.
Hence, while both statements are correct, the reason (R) is providing the correct explanation for why the work done on a positive charge on an equipotential surface is always zero.
As there is no force along the surface of the equipotential surface, the electric field must be perpendicular to the surface.
Hence, while both statements are correct, the reason (R) is providing the correct explanation for why the work done on a positive charge on an equipotential surface is always zero.