1.   State an equation that links power, current and resistance.

2.   Calculate the missing values in the table below.

3.   A heating element has a resistance of 57·5 Ω and draws a current of 4 A. Calculate its power.

4.   What current will be drawn by a low voltage 48 W light bulb which has a resistance of 3 Ω.

5.   A circuit has a resistance of 4 kΩ. Calculate the power of the circuit if the current flowing in the circuit is 3 mA.

6.   A 100 Ω resistor used in a circuit is rated at 0·5 W. What is the maximum current that can flow through it if used at its maximum rating?

7.   A portable camping heater has a power rating of 920 W. It is connected to a mains power point at 230 V.

(a)   What will be the current to the heater when it is operational?

(b)   Calculate the resistance of the heating element.