Ohm's law and resistance
By looking at a number of examples of non-ohmic behaviour, students can learn to distinguish between the definition of resistance (R = V/I) and Ohm's Law (R is independent of I, V).
Experiments
Measuring resistance with a voltmeter and an ammeter
Relationship between volts and amps for electrolytes
Voltage/current relationship for a gas
A transistor as a current amplifier
Crossed wires - electrical fault-finding
Temperature change and resistance
Making an electric arc work from the mains
Related Guidance
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