G3 Electricity and Controls: What's Tested and How to Study It
Circuits, meters, wiring, transformers and the electrical theory the G3 exam expects.
You do not need to be an electrician, but you do need enough electrical theory to work safely on appliance controls and to read a wiring diagram. The questions stay at the level of Ohm's law, series and parallel behaviour, and correct meter use.
What does the G3 exam test on Electricity and Controls?
Circuits, meters, wiring, transformers and the electrical theory the G3 exam expects. The question bank holds 178 questions in this area,
out of 1,184 across the whole syllabus.
Series and parallel circuits, and how resistance and current behave in each
Ohm's law relationships — what happens to amperage when voltage or resistance changes
Connecting a voltmeter, ammeter and ohmmeter correctly
Wire gauge and current ratings
Transformer types — step up, step down and auto
Reading manufacturer wiring diagrams
How should you study Electricity and Controls for the G3 exam?
Two things pay for themselves: knowing that an ammeter goes in series and a voltmeter in parallel, and being able to say without thinking that adding resistors in parallel lowers total resistance. Both come up repeatedly, in several disguises.
Sample G3 exam questions on Electricity and Controls
Five real questions from this topic, with the answers shown. The app holds
178 in this area alone, out of 1,184 across the whole syllabus.
Current flowing in an electrical circuit is measured in:
Ohms
✓ Amps
Watts
Volts
What setting must a gas technician use when measuring an unknown source of power with an analogue meter?
Lowest resistance setting
Highest resistance setting
Lowest voltage setting
✓ Highest voltage setting
What is impedance in an AC circuit?
The power consumed by the circuit
The voltage applied to the circuit
The flow of electrons
✓ The total opposition to AC current flow
What is a capacitors job?
to increase load amps
none of the above
✓ to store energy
to decrease load amps and increase starting torque
What is the name for a valve which is normally closed and allows flow in only one direction?