In metals, current flows due to the movement of :

1. protons
2. neutrons
3. electrons
4. electrons and protons

The conventional current is in a direction …………… the direction of motion of electrons.

1. parallel
2. normal
3. opposite
4. none of the above

A …………… is a device by which resistance in a circuit can be varied continuously.

1. key
2. switch
3. rheostat
4. voltmeter

Rheostat is used in a circuit to provide :

1. fixed current
2. fixed voltage
3. fixed resistance
4. variable resistance