Science--Chapter 3B

Chapter 3B

Electricity and Magnetism

1. What is electric current?
An object gest an electric charge when it gains or loses negative charges.
An electric current will not flow unless it has a closed pathway, or circuit, to flow through.

2. How do electric circuits work?
Series circuits and parallel circuits are two types of electric circuits.
You need to use electricity safely because it can be dangerous.

3. What is magnetism?
Magnets have a magnetic field that is strongest at its poles.
A compass works because of the earth's magnetism.

4. How do electricity and magnetism work together?
A magnet moving inside a coil of wire makes electricity.
An electric current flowing through a wire causes the wire to become magnetic.
Electromagnets are useful in the home because they can be turned on and off.

Vocabulary

resistance     a measure of how much material opposes the flow of electric current and changes electric current into heat energy

conductor     a material through which electric current passes easily

insulator     a material through which electric current does not pass easily

series circuit     a circuit that connects several objects one after another so that the current flows in a single path

parallel circuit    a circuit that connects several objects in a way that the current for each object has its own path

magnet     anything that pulls iron, steel, and certain other metals to it

magnetism   the force around a manget

magnetic field   the space around a magnet where magnetism acts

pole     a place on a magnet where magnetism is strongest

compass   a small magnet that can turn freely

generator     a machine that uses an energy source and a magnet to make electricity

electromagnet   a magnet made when an electric current flows through a wire