Two coils sharing an iron core, never touching, yet one feeds power to the other across the gap. By choosing how many times each coil is wound, a transformer can raise or lower an alternating voltage almost at will.
A transformer changes an alternating voltage using two coils on a soft iron core. The changing field from the primary induces an e.m.f. in the secondary. More turns on the secondary steps the voltage up; fewer steps it down. The grid steps voltage up for efficient transmission and down for safe use.
A transformer changes the voltage of an alternating supply. An alternating current in the primary coil makes a changing magnetic field in the soft iron core, which induces an alternating e.m.f. in the secondary coil.
Transformers work only with a.c. The grid steps voltage up to transmit, then down to use.
Change the turns on each coil and watch the secondary voltage step up or down.
Four quick checks. Each correct answer earns XP and lights this skill on your star map.
A transformer is used to change the...
A step-up transformer has more turns on the...
A transformer works only with...
The core of a transformer is usually made of...
The grid raises the voltage for transmission and lowers it again for homes.
A transformer works only with alternating current, because it needs a changing magnetic field to induce an e.m.f. in the secondary. A steady direct current would induce nothing once the field had settled.
Unlocks once the four checks above are done. Worth more XP, written in the style of Paper 2.
A transformer has fewer turns on its secondary coil than its primary. It is a...
Why is electrical energy transmitted across the National Grid at very high voltage?
A transformer connected to a steady direct current supply gives no output because...
Transformers are mapped. Keep the chain going.