1) When the switch in the circuit shown below is closed, all four lamps light up. When a short circuit is set up across one of the lamps, only one lamp remains lit.
Which lamp has the short circuit set up across it?

2) If a current of 4 A flows in the circuit shown below, what is the resistance of the resistor R?

3) In the following circuits, the cell has negligible internal resistance and the voltmeter is an ideal meter. If the resistance of the rheostat can vary from 0 Ω to 200 Ω, in which of the following circuits will the voltmeter reading change when the resistance of the rheostat changes?

4) The four circuits below are all set up using identical lamps, batteries and resistors.

In which circuit will the lamp be brightest?

5) The diagram below shows a thermistor connected in a circuit with two other resistors.

What will be the changes in the ammeter and voltmeter readings when the temperature of the surrounding increases?