# Generators and Motors A device that converts mechanical energy

```Topic 6: Generators and Motors A device that converts mechanical energy into electrical energy is known as a GENERATOR. What materials are needed to assemble an electromagnet (there are three things)? A power source, a coil of wire, and a soft iron core. AC stands for ALTERNATING CURRENT (two words). DC stands for DIRECT CURRENT (two words). An AC GENERATOR has a coil of wire rotating inside a stationary field magnet. Massive AC GENERATORS can be used to power entire cities. A DC GENERATOR is also called a dynamo. It sends current in only one direction because of how the armature is connected to a split ring commutator. An electric motor is constructed in the same way was a generator, but instead it takes ELECTRIC ENERGY (two words) and converts it to MECHANICAL ENERGY (two words). Topic 7: Electricity in the Home Define TRANSFORMER (but remember that there are two types): Can increase or decrease voltage for efficient transmission over long distances. “Step up” transformers increase voltage, “step down” decreases voltage. Define CIRCUIT BREAKER: A switch and safety device that can cut off all power coming into the home. Electrical cables contain three wires. Name them, describe what they do, and what colour each one is. Black (hot), white (neutral), copper/green (ground). Only the black and white wires carry electrical current. Define POWER: Energy per unit of time. In electricity, it’s the amount of electric energy (measured in joules) that is converted into other forms of energy every second. Label the two triangles using power, energy, and time in one, and power, current, and voltage in the other. Also include the units of each. P