# Power

• Power in an electrical circuit is a measure of the amount of work done per unit time. It is also defined as the rate at which energy is transferred or converted.

• The unit for power is Watts (W). Each watt equals one joule of energy per second.

• The formula used to calculate power is Power (P) = Voltage (V) * Current (I).

• Therefore, it’s essential to understand that power depends on both the voltage across an electric device and the current flowing through it.

• Another formula to calculate power is Power (P) = Current^2 (I^2) * Resistance (R). This shows that power also depends on current and resistance.

• Power dissipation in electronic devices, such as resistors, occurs when electrical energy is turned into heat. This transformation can affect the performance of electronic devices.

• Power is always conserved in an electrical circuit, which means the total power supplied to the circuit equals the total power taken by all components in the circuit.

• In a parallel circuit, the total power consumed equals the sum of the power consumed by all components. In a series circuit, power can be calculated using the total voltage and total current.

• The energy transferred per unit of time by an electric appliance can be calculated by multiplying its power rating by the time it is in use. The usual unit for this is kilowatt-hour (kWh), common in household electricity usage measurements.

In conclusion, mastering the concept of power in electrical circuits involves a solid grasp of “Voltage,” “Current,” and “Resistance” to apply these principles to problem-solving.