A dynamo is rotated at steady speed while disconnected from a lamp. The lamp is then connected and lights. The same speed is maintained.
Why must a greater turning force now be applied?
The induced current produces a magnetic effect assisting the rotation.
The induced current produces a magnetic effect opposing the rotation.
The lamp increases the magnetic energy without taking mechanical energy.
The lamp stops induction so the coil must force charge through the circuit.
92 exam-style questions on Edexcel GCSE Physics 13.1 Inducing a current, covering 13.1.1 Producing an electric current by induction, 13.1.2 Factors affecting the induced potential difference, 13.1.3 Alternators and dynamos, and 13.1.4 Microphones and loudspeakers. Each one has a worked solution and a mark scheme showing where the marks go.