Current Electricity Set 3

In a thermo-couple, one junction which is at 0 and the othe at the emf is given by . The neutral temperature is given by

5 cells, each of emf and internal resistance are connected to an external circuit of resistance of Find the current through external circuit

Two heater wires of equal length are first connected in series and then in parallel. The ratio of heat produced in the two cases is

A combination of two resistance of 2 W and 2/3 W connected in parallel is joined across a battery of emf of 3 V and of negligible internal resistance. The energy given out per sec will be

When a piece of aluminium wire of finite length is drawn through a series of dies to reduce its diameter to half its original value, its resistance will become