Electromagnet

1. Wind insulated wire into a coil. 2. Place a soft iron core inside. 3. Connect the coil to a battery. 4. Current through the coil creates magnetism. 5. Switch off current to remove magnetism.

Draw a coil wound around a soft iron nail with battery connections and labeled north and south poles at the ends.

A common wrong answer is that the iron core stays magnetised permanently like steel. That is wrong because soft iron loses magnetism quickly.

An electromagnet is a temporary magnet produced by electric current through a coil, usually wound around a soft iron core.

An electromagnet is a temporary magnet produced by electric current through a coil, usually wound around a soft iron core. Strength of an electromagnet increases with current, number of turns, and use of a soft iron core. A scrapyard crane uses a strong electromagnet to lift iron pieces and releases them when the current is switched off.

An electromagnet works only when current flows. The soft iron core becomes magnetised quickly and loses magnetism when current is switched off. That makes an electromagnet very useful in bells, cranes, relays, and electric motors. Its strength can be changed by increasing current, turns, or core quality. Strength of an electromagnet increases with current, number of turns, and use of a soft iron core. If the current in a crane's coil is increased, the electromagnet becomes stronger and can lift more iron scrap. When the current is switched off, the scrap is released easily. Explain construction, working, uses, or advantages of an electromagnet over a permanent magnet. A common wrong answer is that the iron core stays magnetised permanently like steel. That is wrong because soft iron loses magnetism quickly.