Required Practical: I-V Characteristics

This lesson covers the Required Practical on investigating the I–V characteristics of a filament lamp, a diode and a resistor, as specified by AQA GCSE Physics (4.2.1). This is Required Practical Activity 16 and is frequently examined — you must be able to describe the method, draw the circuit, sketch the results and explain the shapes of the graphs.

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Aim

To investigate the relationship between potential difference and current for a filament lamp, a diode and a resistor at constant temperature, and to produce I–V characteristic graphs for each component.

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Equipment List

Equipment	Purpose
Filament lamp	Component under investigation
Diode (silicon)	Component under investigation
Resistor (fixed value, e.g., 10 ohms)	Component under investigation
Variable resistor (rheostat)	To vary the p.d. across the component
Ammeter	To measure the current through the component
Voltmeter	To measure the p.d. across the component
Power supply (d.c., low voltage)	To provide the potential difference
Switch	To control the circuit
Connecting leads	To connect the circuit