Review the key concepts, formulae, and examples before starting your quiz.
🔑Concepts
A magnet is an object that produces a magnetic field and exerts a force of attraction or repulsion on other materials.
Magnetic materials are materials that are attracted to a magnet. The most common magnetic metals are iron, nickel, and cobalt.
Steel is a magnetic alloy because it is made primarily of iron.
Non-magnetic materials are materials that are not attracted to magnets. Examples include wood, plastic, glass, rubber, and non-magnetic metals like , , , and .
Magnets have two ends called poles: the North Pole () and the South Pole ().
The magnetic force is strongest at the poles of the magnet.
Like poles (same poles) push away from each other; this is called repulsion ( or ).
Opposite poles pull towards each other; this is called attraction ().
📐Formulae
💡Examples
Problem 1:
Sarah has a collection of objects: a steel paperclip, a plastic ruler, a copper penny, and an iron nail. Which of these will be attracted to a bar magnet?
Solution:
The steel paperclip and the iron nail.
Explanation:
Iron and steel (which contains iron) are magnetic materials. Plastic and copper are non-magnetic materials and will not be attracted to the magnet.
Problem 2:
If you try to push the North pole of one magnet against the North pole of another magnet, what force will you feel?
Solution:
A force of repulsion ().
Explanation:
According to the laws of magnetism, like poles repel each other. Since both poles are North ( and ), they will push away from each other.
Problem 3:
Why is a soda can made of aluminum considered non-magnetic?
Solution:
Because aluminum is a non-magnetic metal.
Explanation:
Not all metals are magnetic. Only specific metals like iron, nickel, and cobalt respond to magnetic forces. Aluminum does not contain these elements in sufficient quantities to be magnetic.