As wire XY is moved downwards between the poles of a magnet that is not moving, an e.m.f. is induced across X and Y. Which action would induce an e.m.f. across X and Y in the opposite direction?
- AMove both the wire and the magnet upwards at the same speed.
- BThe wire is kept stationary and the magnet is moved upwards.
- CThe wire is moved downwards and the magnet is moved upwards.
- DThe wire is moved upwards and the magnet is kept stationary.