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Magnetism
8th Grde Science - Brandt
Question | Answer |
---|---|
Name the three particles that make up an atom, and their charges. | Proton (+), neutron (neutral), electron (-) |
What positive particle is located in the nucleus of the atom? | Proton |
Electricity is defined as the movement of these negatively charged particles. | Electrons |
Define static electricity. | The buildup of electrons on a substance (usually an insulator) |
What is the difference between static and current electricity? | In static electricity, electrons build up; in current electricity, they flow through a conductor in a complete circuit. |
The force produced by a magnetic field is called _______ | Magnetism |
What do we call materials that have atomic structures that cause them to be magnetic? | Permanent magnets |
What are the only materials that are naturally magnetic? | Iron, nickel, and cobalt |
Why do some materials form natural magnets? | They have domains (groups of atoms) that are arranged with poles. When these poles are lined up, the material becomes magnetic. |
How can you create magnetic alignment in these materials? | Stroke the material in one direction with a magnet. |
What happens to the domains in a magnet when you drop or heat it? | The domains may lose alignment, and the magnet is weakened. |
This surrounds a magnet, and is strongest close to the magnet | A magnetic field. |
What is a temporary magnet made by placing a piece of iron inside a current carrying coil of wire? | An electromagnet |
This device changes electrical energy into mechanical energy by allowing an electromagnet to spin freely between the poles of a fixed permanent magnet | Electric motor |
This device produces electric current when a coil of wire rotates within a magnetic field | generator |
What are the two types of current, and what produces/provides them? | AC - Alternating Current - Generator; DC - Direct Current - battery |
What is the difference between the two types of current? | DC flows in only one direction, and AC alternates back and forth. |
How do electricity and magnetism work together in electromagnetism? | Moving charges create a magnetic field, and magnetic fields make current flow. |
When an object is magnetic, where do all the domains in it point? | In the same direction |
How is magnetism like electricity? | In both electricity and magnetism, opposites attract, and like repels. |
What is the main difference between magnetism and electricity? | In electricity, you are dealing with charges, in magnetism, you are dealing with poles. |
A device that increases or decreases the voltage of an alternating current | Transformer |
What are the three parts of an electromagnet? | A wire coil which generates a magnetic field, a metal (usually iron) core, and a voltage source. |