In a laboratory experiment a point charge is moved very slowly (so that its kinetic…
PHYSICS · Multi-part · CBSE · Physics · Electrostatic Potential and Capacitance · Electrostatic Potential and Capacitance
Problem
In a laboratory experiment a +3.0μC point charge is moved very slowly (so that its kinetic energy remains essentially zero) from point A, where the electric potential is 120V, to point B, where the electric potential is 25V. Neglect all other interactions.
(a) Calculate the change in electric potential energy of the charge–field system as the charge moves from A to B. Include the algebraic sign and appropriate units.
(b) Determine the magnitude and sign of the work that must be done by an external agent to accomplish this displacement at negligible speed.
(c) If the charge were instead released from rest at A and allowed to move freely to B, describe qualitatively (no numbers necessary) the changes, if any, in the kinetic energy of the charge and in the work done by the field.