Given below are two statements : one is labelled a 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 :
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 :
- (A)Both (A) and (R) are correct but (R) is not the correct explanation of (A)
- (B)((A) is correct but (R) is not correct
- (C)(A) is not correct but (R) is correct
- (D)Both (A) and (R) are correct and (R) is the correct explanation of (A)✓ Correct
Answer: (D)
Solution
On an equipotential surface the potential is constant, and the work done moving a charge between two points is ; with , — Assertion (A) is correct. The electric field is the negative gradient of potential and has no component along a surface of constant potential, so field lines are always perpendicular to equipotential surfaces — Reason (R) is correct. This perpendicularity is exactly why the force on the charge is perpendicular to any displacement along the surface, making ; (R) is the correct explanation of (A).
JEE Main · 2024 · 27 Jan 2024 · Shift 2 · Single correct option