Experiment 6 — Build an Electromagnet

Topic: Physics · Classes 6–7 · Electric current and its magnetic effect

Aim: Lift at least 10 pins — then switch the current off and watch what happens.

Daily: Electric bells, doorbells, loudspeakers, electric motors and the giant scrapyard cranes that pick up cars all rely on electromagnets. Unlike a permanent magnet, they can be switched off — which is exactly what makes them useful.

Question: You replace the iron nail inside the coil with a plastic rod, keeping everything else the same. The electromagnet will…

Exp: Iron concentrates the magnetic field; plastic does not, so the magnet becomes very weak.

Question: An electromagnet is made by…

Exp: Current in a coil produces a magnetic field.

Question: Which change does NOT strengthen an electromagnet?

Exp: Only an iron (magnetic) core strengthens it.

Question: The main advantage of an electromagnet is that it…

Exp: Control is what makes it useful in bells, relays and cranes.

Question: Who first noticed a compass needle move near a current?

Exp: Oersted’s 1820 observation linked electricity and magnetism.