Two wires A and B of the same material, having radii in the ratio 1:2 and carry currents in the ratio 4 : 1. The ratio of drift speed of electrons in A and B is

A cell of negligible resistance and e.m.f. 2 volt is connected to series combination of 2, 3 and 5 ohm. The potential difference in volt between the terminals of 3 ohm resistance will be

Five cells each of e.m.f. E and internal resistance r are connected in series. If due to oversight, one cell is connected wrongly, then the equivalent e.m.f. and internal resistance of the combination is

A constant voltage is applied between the two ends of a uniform metallic wire. Same heat is developed in it. The heat develped is doubled if

The masses of the three wires of copper are in the ratio 1 : 3 : 5.And their lengths are in the ratio of 5 : 3 : 1. The ratio of their electrical resistance is

The resistance of a metallic conductor increases with temperature due to

If the length of the filament of a heater is reduced by 10% , the power of the heater will