**Energy (E)** is measured in** joules (J).**

**Power (P)** is measured in **watts (W).** Power is the rate at which energy is transferred. One watt is equal to one joule per second ( 1 W = 1 J s^{-1} ).

- E = energy in joules, J
- V = potential difference in volts,V
- I = current in amperes, A
- t = time in seconds, s

- P = power in watts, W
- V = potential difference in volts, V
- I = current in amperes, A

- P = power in watts, W
- I = current in amperes, A
- R = resistance in ohm’s, W

Examples;

Q1) How much energy is dissipated by a resistor if a potential difference of 9.0V is applied to it for 331 seconds and a current of 0.23 A flows through it?

Q2) What is the current flowing through a bulb if it has a power of 100W when the potential difference supplied to it is 230V?

Q3) What is the power dissipated by a 32 ohm resistor when a current of 1.4 A flows through it?