Physics · Unit 1 · Electrical circuits · Current, potential difference and energy flow
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A physics student constructs a simple circuit using a copper wire connected to a 1.5 V battery. She measures a steady current of 0.30 A flowing through the wire. Her teacher asks her to explain what is physically happening inside the wire to produce this current. Using your knowledge of charge carriers in conductors, describe the microscopic process that results in the observed electric current in the copper wire.
Describe how electric current is carried in a metallic conductor.
A student investigates charge flow in a copper wire by measuring current at various points in a simple circuit. The wire has a cross-sectional area of 1.5 mm² and carries a steady current of 2.4 A. Each copper atom contributes approximately one free electron, and copper has a density of 8,900 kg/m³ and a molar mass of 63.5 g/mol. Describe how electric current is carried through the copper wire, identifying the charge carriers and explaining the nature of their motion.