GCSE Physics practice questions on induction, generators and transformers. Try 3 for free below — with hints, the answer and why the wrong answers are tempting. GCSE Beast has 26 questions on this topic, from first steps to the hardest exam-style problems.
For a science-fair project, a student builds a small transformer by winding two coils of insulated wire on a closed core.
Which row gives the best material for the wire of the coils and the best material for the core?
| wire of the coils | core | |
|---|---|---|
| A | copper | copper |
| B | copper | soft iron |
| C | soft iron | copper |
| D | soft iron | soft iron |
A garden pond pump is designed to run on an alternating p.d. of 24 V. A shop offers four transformers that plug into the 230 V mains. The table gives the numbers of turns on their two coils. Each transformer is 100 % efficient.
Which transformer will run the pump at its correct p.d.?
| turns on the primary (mains) coil | turns on the secondary (pump) coil | |
|---|---|---|
| A | 240 | 2300 |
| B | 2300 | 24 |
| C | 2300 | 240 |
| D | 2300 | 480 |
Some electric scooters slow down by using their motor as a generator. A simple model is a copper rod pulled to the right through a magnetic field that points out of the page. The rod is joined to a meter by flexible wires, so a current is induced in the rod.
The induced current causes a magnetic force on the rod. In which direction is this force?
