PHYSICS · Multi-part · CBSE · Physics · Electrostatic Potential and Capacitance · Electrostatic Potential and Capacitance
Problem
Two identical solid rods, one of copper and the other of glass, are each 10 cm long and 2 cm in radius. Every part of the copper rod is connected to the positive terminal of a 200 V supply, while the glass rod is held with one end touching the same terminal but the rest is insulated from the surroundings.
(i) State the kind of charges (free or bound) that can exist inside each rod after a long time. Give a reason for your answer in each case.
(ii) What will be the electric field at a point just inside (a) the lateral surface of the copper rod, (b) the lateral surface of the glass rod? Justify your answers without calculation.
(iii) If a small piece of aluminium foil is gently laid on the surface midway along the length of each rod, describe and explain the subsequent behaviour of the foil in the two cases.