1. A resistor of unknown resistance is connected to a cell. A voltmeter and an ammeter are also fitted to the circuit.
a) Draw a diagram of the circuit to show how all the components can be connected.
[3]
The voltmeter gives a reading of 5.6 V and the ammeter gives a reading of 2 mA.
b) Find the unknown resistance of the resistor. [2]
c) If current flows for 3 minutes through the resistor, what is the total electrical energy
dissipated? [2]
2. A battery of emf 8 V is used to light up a bulb.
a) What is the energy transformation that takes place in a battery? [2]
b) How much electrical energy would be delivered to 3 kC of charge flowing in the circuit?
[2]
c) What is the energy transformation that takes place in the bulb? [2]
d) If the efficiency of the bulb is 80%, what amount of light energy is given off? [2]
e) What is the p. d across the bulb? [1]
Total Marks : 16