Learn how electric circuits work and how to measure current and potential difference with this guide for KS3 physics students aged 11-14 from BBC Bitesize.

Last time, we learned that when there's a difference in electric potential between two points, the voltage gives charged particles, like electrons, the energy to move from one place to another.

Suppose there were two point charges, both positive but one is held in place. If I hold the other point charge a distance r away from the other charge and let go, what will happen?

It is the force that drives electric current through a circuit. EMF is measured in volts and is represented by the symbol “ε” (epsilon). On the other hand, potential difference, also known as voltage, ...