Of course, you don’t have to have a scope to do this. You can use a voltmeter and an ammeter, but it is very straightforward if you have a four-channel scope with a pair of current probes.

An ammeter tells you the current, or the flow of charge through the circuit, measured in amps. In this circuit it’s nought point two three amps. And a voltmeter measures the potential difference ...

1m length of constantan wire, a metre rule, a low voltage power pack, a variable resistor, a voltmeter, an ammeter, connecting leads, a switch, 2 crocodile clips, Sellotape. The temperature of the ...