Electromagnetic induction and generatorsIB MYP Physics: Mind map

Exam questions on Electromagnetic induction and generators

1. A student in Lagos connects a coil of wire to a sensitive centre-zero voltmeter and moves a bar magnet into and out of the coil.
   Explain why the voltmeter needle swings the opposite way when the magnet is pulled out of the coil compared with when it is pushed in.2 marks
2. In a school in Santiago, a bar magnet's north pole is pushed towards one end of a coil of wire. The coil is part of a complete circuit that includes a sensitive ammeter.
   Explain, in terms of energy, why it takes effort to push the magnet into the coil.2 marks
3. A simple a.c. generator in a school laboratory has a rectangular coil that is turned between the poles of a magnet. The ends of the coil are connected to slip rings and carbon brushes, and the output is displayed on an oscilloscope as a wave that repeats.
   Explain how the generator produces an alternating e.m.f. when the coil is turned.3 marks