We use electricity to heat and light our homes. Electrical energy transferred is calculated by multiplying current, voltage and time.

For a given amount of electrical charge that moves, the amount of energy transferred increases as the potential difference increases.

Work out the energy transferred using this equation:

energy = current x voltage x time

E = I × V × t

where:

*E* is the energy transferred in joules, J

*I* is the current in amperes, A

*V* is the potential differences in volts, V

*t* is the time in seconds, s

For example, how much energy is transferred in two seconds with a current of 1 ampere and a potential difference of 120 volts.

E = 1 × 120 × 2

= **240 J**

Charge is current multiplied by time so this equation can also be written as:

E = V × Q

where:

*E* is the energy transferred in joules, J

*V* is the potential difference in volts, V

*Q* is the charge in coulombs, C

For example, how much energy is transferred when the potential difference is 120 V and the charge is 2 C?

Energy transferred

= 120 × 2

= **240 J**