POWER (ELECTRICAL)

=Power= Recall that '''Power''' is the rate at which work is done (or energy is transformed). It can be measured as the amount of work done (energy transformed) per second. ===[image:http://i.imgur.com/bwkX3kf.png]=== === ==='''P''' (Power), '''W''' (Work) and '''t''' (Time) Power is measured in Watts (W). A device that is rated 1 kW uses 1000 Joules of energy per second. In an electrical circuit, energy is also transformed. The power of a component can be calculated using the formula: $$P=V\times I $$ OR $$ P= I^2R$$ ==Example== Calculate the power of the resistor: [image:http://i.imgur.com/NxIolx9.png] First, calculate the current through the resistor: $$I=\frac{V}{R}$$ $$I=\frac{5}{10}$$ $$I = 0.5A$$ Now use: $$ P= I^2R$$ $$ P= 0.5^2 \times 10$$ $$ P= 2.5W$$