MHT-CET Physics Electrostatics PYQ - Electric Potential Energy Change

12) If a unit charge is shifted from a region of low potential to a region of high potential, then the electric potential energy of the system:

A. Increases

B. Decreases

C. Does not change

D. Is zero

Solution:

The electric potential energy \(U\) of a charge \(q\) in a potential \(V\) is given by: \[ U = qV. \]

For a unit charge (\(q = 1\)), the potential energy is numerically equal to the potential: \[ U = V. \] When the charge is moved from a region of low potential (say \(V_{\text{low}}\)) to a region of high potential (\(V_{\text{high}}\)), the potential increases (\(V_{\text{high}} > V_{\text{low}}\)). Consequently, the potential energy increases: \[ \Delta U = U_{\text{high}} - U_{\text{low}} = V_{\text{high}} - V_{\text{low}} > 0. \]

Therefore, the electric potential energy of the system increases. The correct answer is option A.