Why must electrostatic field at the surface of a charged conductor be normal to the surface at every point ? Give reason.
Why are electric field lines perpendicular at a point on an equipotential surface of a conductor ?
The electric potential due to point charge 3 nC at distance of 9 cm is
(a) 270 v
(b) 3 v
(c) 300 v
(d) 30 v
Calculate the amount of work done to dissociate a system of three charges 1 mC, 1 mC and – 4 mC placed on the vertices of an equilateral triangle of side 10 cm.
Obtain the expression for the potential due to an electric dipole of dipole moment p at a point ‘d’ on the axial line.
Why should electrostatic field be zero inside a conductor ?
Two equal balls having equal positive charge ‘q’ coulombs are suspended by two insulating strings of equal length. What would be the effect on the force when a plastic sheet is inserted between the two ?
Does the charge given to a metallic sphere depend on whether it is hollow or solid?
The emf of a cell is always greater than its terminal voltage. Why ? Give reason.
Nichrome and copper wires of same length and same radius are connected in series. Current I is passed through them. Which wire gets heated up more ? Justify your answer.
A 10 V battery of negligible internal resistance is connected across a 200 V battery and a resistance of 38Ω as shown in the figure. Find the value of the current in the circuit.