A student investigates the relationship between the length and the resistance of a wire.
The following apparatus is available:
Other apparatus normally found in a school laboratory is also available.
Plan an experiment to investigate how the length of a wire affects its resistance.
Resistance RRR is given by the equation R=VIR = \frac{V}{I}R=IV, where VVV is the potential difference (p.d.) across the wire and III is the current in the wire.
You do not need to write about safety precautions.
In your plan:
452 exam-style questions on CIE IGCSE Physics 4.2 Electrical quantities, covering 4.2.1a Positive and negative charge, 4.2.1b Charging by friction and detecting charge, 4.2.1c Electrical conductors and insulators, 4.2.1d Electric fields and electric field patterns, 4.2.2a Electric current, charge and measuring current, 4.2.2b Conduction in metals and the direction of current, 4.2.2c Direct current and alternating current, 4.2.3a Electromotive force, 4.2.3b Potential difference and voltmeters, 4.2.4a Resistance, 4.2.4b Resistance of a metallic wire, 4.2.4c Current–voltage graphs, and 4.2.5 Electrical energy and electrical power. Each one has a worked solution and a mark scheme showing where the marks go.