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.

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

Find the effective resistance of the combination of two resistors of resistances 10 Omega and 15 Omega connected in series (ii) parallel.