Magnetism and Electromagnetism
4 marks · EasyA student has a collection of materials: iron nail, copper coin, glass marble, and steel pin.
State which of these materials are magnetic, and which are not. Give one property that distinguishes magnetic materials from non-magnetic materials.
Explain why steel is used to make permanent magnets, but iron is not.
Work this out on paper, then compare with the answer and worked solution below. With a free account you can submit written answers for marking.
Show answer
(a) Iron nail and steel pin are magnetic; copper coin and glass marble are not. Magnetic materials are attracted by magnets; non-magnetic materials are not. · must show Iron—magnetic, Steel—magnetic, Copper—non-magnetic, Glass—non-magnetic, Property: attraction to magnets
(b) Steel is used for permanent magnets because it is magnetically hard and keeps its magnetism; iron is magnetically soft and loses its magnetism easily. · must show Steel—magnetically hard, Keeps magnetism, Iron—magnetically soft, Loses magnetism
Common mistakes: Claiming copper is magnetic; Confusing hardness with strength
Show mark scheme and worked solution
Marking points
B1 (a) · 1 mark · Correctly identifies which materials are magnetic or not.
B2 (a) · 1 mark · States a property that distinguishes magnetic from non-magnetic materials.
B3 (b) · 1 mark · Explains why steel makes good permanent magnets (magnetically hard).
B4 (b) · 1 mark · States that iron is magnetically soft and loses magnetism easily.
Worked solution
a) The iron nail and steel pin are magnetic materials because they are attracted to magnets. Copper coin and glass marble are not magnetic: they are not attracted by magnets. Magnetic materials can be attracted by a magnet; non-magnetic materials cannot.
b) Steel is magnetically hard, so when it is magnetised, it keeps its magnetism and is used for permanent magnets. Iron is magnetically soft and loses its magnetism easily, so it is not used for permanent magnets.