UNIT OVERVIEW

Every time you switch on a light, charge your phone, or see your family's electricity bill arrive, you are dealing with electrical energy and power. In this unit, you will learn the mathematics behind electricity consumption and understand exactly what you pay for when the electricity bill comes.

You have already explored electrostatics (stationary charges) and electromagnetism (the connection between electricity and magnetism). Now we bring it all together in electric circuits — the controlled flow of charges that powers our modern world.

What You Will Learn

• The relationship between electrical energy, power, potential difference, and current
• How to calculate power using three different formulae: $P = VI$, $P = I^2R$, and $P = \frac{V^2}{R}$
• The kilowatt-hour (kWh) as the practical unit for electrical energy
• How to calculate the cost of electricity for household appliances
• How to investigate Ohm's Law experimentally with resistors and light bulbs
• The difference between ohmic and non-ohmic conductors

Real-Life Applications