Uplearn EMF and PD

e.m.f

The change in electric potential energy per unit charge between two points, due to work being done on the charge, for example by a battery or a power supply

volt

volt is the potential difference between two points when a 1 C charge passing between the points experiences a change in electric potential energy of 1 J

why does a voltmeter have a high resistance?

so that current does not flow through the voltmeter

Potential difference (p.d.)

The change in potential energy per unit charge between two points, due to the charge doing work on circuit components

Kinetic energy of electrons

When a potential difference accelerates a charged particle, the energy transferred is equal to the kinetic energy gained by the particle (usually an electron)