Magnetism 5Transformers & Generators

TransformerDevice in which alternating current in one coil of wire induces a current in a second wire.

Primary coil (input) is connected to a source of ___________ _______Alternating current

This induces a current in the ___________ _____(output)__Secondary coil

Step-up Transformer

• Increases Output Voltage • Has more turns of wire in

the second coil• More turns of coil =

higher Voltage• Power companies use

them to send electricity over long distances

• Examples: neon sign or plug for CD player

Step-down Transformer

• Decreases output voltage

• Fewer turns of wire in second coil

• Fewer turns of wire = lower voltage

• Power to individual homes

GeneratorDevice that changes mechanical energy into electrical energy.

• It has the ability to induce a current.

•Electricity usually comes from generators.

How it works

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•A loop of wire spins through a magnetic field.

•Moving magnets make electricity.

MotorDevice that changes electrical energy into

mechanical energy

•It has the ability to reverse poles of an electromagnet

•Has electromagnet & permanent magnet

•How it works-

•the electromagnet is free to turn in the middle of permanent magnets.

•Changing + & - in the electromagnet changes the attraction or repulsion towards the permanent magnet.

TurbineTurbine – an engine that….removes energy from a fluid or air flow and converts it into useful work.

Steam Turbine – is used for the……

generation of electricity in thermal power plants, such as plants using coal or fuel oil or nuclear power.

Almost all electrical power on Earth is produced with a turbine of some type.

Mechanical Energy (moving water) spins the turbine. The spinning turbine spins magnets in the generator. Coils of wire surrounding the spinning magnets cut

through the magnetic field which induces a current. The current made by the

generator goes to the power lines. Power lines bring the electricity to your homes,

schools etc.

How mechanical energy is transformed into electricity.