Physics · May / June 2016 · Paper 12 · Question 32

The diagram shows a simple d.c. motor. [diagram of a simple d.c. motor with N and S poles, a coil, commutator and battery] The switch is closed and the coil rotates. Which change makes the coil rotate in the opposite direction and at a faster rate?

1. Aincrease the current in the coil and increase the number of turns in the coil
2. Breverse both the magnetic field and the current in the coil
3. Creverse the magnetic field and decrease the current in the coil
4. Dreverse the magnetic field and increase the current in the coil

As printed in the paper