PHYSICS · Single correct · CBSE · Physics · Electrostatic Potential and Capacitance · Electrostatic Potential and Capacitance
Problem
In Millikan's oil-drop experiment, an oil drop of radius r and charge q is held in equilibrium between the plates of a charged parallel-plate capacitor when the potential difference is V. To keep a drop of radius 2r and charge 2q in equilibrium between the plates, the required potential difference is
(1) V
(2) 2V
(3) 4V
(4) 8V