• When charge passes through a power supply such as a battery, it?gains?electrical energy
• The?electromotive force (e.m.f.)?is defined as:

The amount of chemical energy converted to electrical energy per unit charge?when charge passes through a power supply

• e.m.f. is measured in?Volts (V)

Definition of e.m.f. with regards to energy transfer

• This can also be written as:

• E.m.f. is:
  • represented by the symbol?ε?(greek letter epsilon)
  • not actually a force, but a measure of energy transferred per coulomb of charge
  • is measured in?volts (V), which is J C?1?in S.I. units

• e.m.f. is also the potential difference across the cell when no current is flowing
• e.m.f. can be measured by connecting a high-resistance voltmeter around the terminals of the cell in an open circuit

e.m.f. is measured using a voltmeter connected in parallel with the cell