Current Electricity

The masses of three wires of copper are in the ratio 1:3:5 and lengths

The masses of three wires of copper are in the ratio 1:3:5 and lengths are in the ratio 5:3:1. Then…

If voltage across a bulb rated 220 volt-100 Watt drops by 2.5% of its rated value

If voltage across a bulb rated 220 volt-100 Watt drops by 2.5% of its rated value, the percentage of the…

A wire having resistance 12Ω is bent in the form of an equilateral triangle.

A wire having resistance 12Ω is bent in the form of an equilateral triangle. The effective resistance between any two…

When current I is flowing through a conductor, the drift velocity is v.

When current I is flowing through a conductor, the drift velocity is v. If the value of current through the…

A thermocouple of negligible resistance produces an e.m.f. of 40 µV/⁰C in the linear range

A thermocouple of negligible resistance produces an e.m.f. of 40 µV/⁰C in the linear range of temperature. A galvanometer of…

The rate of increase of thermo-e.m.f. with temperature at the neutral temperature

The rate of increase of thermo-e.m.f. with temperature at the neutral temperature of a thermocouple Options (a) is positive (b)…

Two cells when connected in series are balanced on 8m on a potentiometer.

Two cells when connected in series are balanced on 8m on a potentiometer. If the cells are connected with polarities…

The thermo e.m.f. E in volts of a certain thermocouple is found to vary

The thermo e.m.f. E in volts of a certain thermocouple is found to vary with temperature difference θ in ⁰C…

Two bulbs when connected in parallel to a source take 60W each, the power consumed,

Two bulbs when connected in parallel to a source take 60W each, the power consumed, when they are connected in…

The resistance of a bulb filament is 100 Ω at a temperature of 100⁰C.

The resistance of a bulb filament is 100 Ω at a temperature of 100⁰C. If its temperature coefficient of resistance…