A current sensor is connected to the output of a portable generator. The sensor records a sinusoidal current with a frequency of 50 Hz.
The negative peak on the recorded trace is labelled P. A reading taken 0.025 s after P is labelled Q.
Which describes the current at Q?
Greatest in the positive direction, after half a cycle.
Zero, after three quarters of a cycle.
Greatest in the negative direction, after one complete cycle.
Zero, after one and a quarter cycles.
81 exam-style questions on Edexcel GCSE Physics 10.4 Mains electricity, covering 10.4.1 Direct and alternating current, 10.4.2 Live, neutral and earth wires; safety, 10.4.3 Mains wire potential differences and dangers, and 10.4.4 Power ratings and energy use. Each one has a worked solution and a mark scheme showing where the marks go.