• Work is also defined as a transfer of energy
• When components transfer electrical energy to other stores, work must be done because energy is transferred
• Therefore,?potential difference is the?work done per unit charge

• Current is the?rate of flow of charge

• These equations can be combined to give the work done by a component in an electric circuit

• Power?P?is defined as:

The rate of doing work

• In equation form this is

• This gives us

• Therefore, the power dissipated (produced) by an electrical device is given by:

• Using?V?=?IR?to rearrange for either?V?or?I?and substituting into the power equation means we also write power in terms of resistance?R

Power equation in terms of resistance

• The squared value for both current and voltage in these equations means that, for any given resistance, if the current or voltage?doubles, the power will be?four?times as great
• Conversely, for a given power, if the resistance?doubles?then current will be 4 times?less?but voltage will be 4 times?greater

ANSWER:??A