Electromotive Force
Physics: Cambridge International GCSE Supplement, topic 4.4.1
Electromotive Force
The electromotive force (e.m.f.) is the electrical work done by a source in moving a unit charge around a complete circuit.
Drives the charges round the circuit
- This energy then drives the charges around a complete circuit (one with no gaps in it).
Measured in volts
- The electromotive force (e.m.f.) is measured in volts (V).
- A mobile phone battery provides an e.m.f. of 3.8 V to drive current through the phone’s circuits.
- A car battery provides an e.m.f. of 12.6 V to drive current through a car’s circuits.
Test yourself on Electromotive Force
What are the units of electromotive force?
Which of the following are true of electromotive force?
What drives current through circuits?