Electrical Power

Lots of formulas so make sure you have pen and paper!

Power

The rate of energy transformation per second

Unit of measurement of Power

Watt (W)

Formula for Watt

W = J/s

Formula for Power

P= I x V or P= VxV/ R

Formula for kWH

kWh = Wh/ 1000

Energy used (Kwh) formula

kWh= Power (kW) x Hours used (h)

Effect of voltage on brightness

More voltage—> More electrons pushed—> More current—> More power (More light emitted)—> More brightness

Effect of resistance on brightness

More resistance—> Electrons moving slowly—> Less current—> Less light emitted (Less power)—> Less brightness

Effect of current on brightness

More current —> More power—> More light being emitted—> More brightness

Relationship of power and brightness:

More power= more energy transformed into light—> more brightness!