Question 4(c)(i)
[Maximum number: 1]
A student investigates how the current in a filament lamp varies with the voltage across it.
The student has this equipment
- filament lamp
- cell
- variable resistor
- ammeter
- voltmeter
- connecting wires
The filament of the lamp is made of metal.
The student suggests that a straight line on the graph is more appropriate than a curve because current is directly proportional to voltage for a metal.
Suggest how the student could improve their investigation to find out whether a straight line or curve is more appropriate.