7 electricity & magnetism

Electricity & Magnetism

Electromagnet- a temporary magnet made by placing a piece of iron inside a current-carrying coil of wire. When current flows through the wire, magnetic-field lines form all around the wire.

When electric current flows through a wire, a magnetic field forms around the wire. The direction of the magnetic field depends on the direction of the current in the wire.

Galvanometers- devices that use an electromagnet to measure electric current.

Ex: gauges on the dashboard of a car.

Generators- produce electric current by rotating a coil of wire in a magnetic field.

Direct Current (DC)- current flows in only one direction through a wire.Ex: battery

Alternating Current (AC)-reverses the direction of the current flow in a regular way.Ex: wall outlet

Transformer- device that increases or decreases the voltage of an AC. Transformers are used to decrease the voltage of the AC before it enters your house.

Step-up for Power Step-down Step-down

Transmission Line for area for house