The resistances of `20Omega` are connected to a source of emf. Calculated the ratio of the heats produced in the two resistances when they are connected (i) In series and (ii) in parallel.

State Ohm's law. Derive the laws of resistances, when they are connected: (i) in series (ii) in parallel.

Find the total resistance when the various resistors are connected (i) in series and (ii) in parallel.

Calculate the equivalent resistance when two resistances of 3 ohms and 6 ohms are connected in parallel.

Two coils of resistances 3 Omega and 6 Omega are connected in series across a battery of emf 12 V . Find the electrical energy consumed in 1 minute in each resistance when these are connected in series.

Two wires have resistance of 2 Omega and 4 Omega connected to same voltage, ratio of heat dissipated at resistance is

A cell of emf 2V produces 0.3A current when connected to a resistor of 5Omega . Calculate the terminal voltage and internal resistance of the cell.

Three equal resistances each of 3Omega are in series and connected to a cell of internal resistance one ohm. If these resistance are in parallel and connected to the same cell, then the ratio of the respective currents through the electric circuits in the two cases is

A potentiometer having a wire of length 10 m and resistance 20 Omega is connected to an accumulator of e.m.f. E through a resistance box. When the resistance in the box is 20Omega, a null point is observed at 5 m for a cell of e.m.f. E_(1) . The ratio of E to E_(1) is