Turn a coil between the poles of a magnet and induction does the rest, pumping out a voltage that rises, falls, reverses and rises again. Every power station in the world is, at heart, this spinning loop.
An a.c. generator spins a coil in a magnetic field, inducing an alternating e.m.f. Slip rings keep the coil connected to the circuit as it turns. The e.m.f. is greatest when the coil sides cut the field fastest and zero when they move along the field, giving a sine-shaped output.
An a.c. generator rotates a coil in a magnetic field. As the coil turns it cuts field lines and induces an alternating e.m.f.. Slip rings and brushes connect the coil to the external circuit.
The e.m.f. is greatest when the coil cuts the field fastest and zero when the coil moves along the field lines.
Rotate the coil and watch the alternating e.m.f. trace out its sine shape.
Four quick checks. Each correct answer earns XP and lights this skill on your star map.
An a.c. generator connects its rotating coil to the circuit using...
As the coil of an a.c. generator turns, it induces...
One full rotation of the coil produces...
The induced e.m.f. is greatest when the coil is...
As the coil turns, the sides cut the field first one way then the other, so the e.m.f. reverses each half turn.
An a.c. generator uses slip rings, not a split-ring commutator. The induced e.m.f. is greatest when the coil is moving fastest across the field lines, and falls to zero twice per turn as the coil moves along them.
Unlocks once the four checks above are done. Worth more XP, written in the style of Paper 2.
How does an a.c. generator differ from a d.c. motor in the way the coil connects to the circuit?
The output e.m.f. of an a.c. generator is momentarily zero when the coil is...
If the coil of an a.c. generator is spun faster, the output e.m.f. becomes...
The a.c. generator is mapped. Keep the chain going.