Answer:
When the elctromagnet is ON, it picks up the iron pieces from the other scrap (copper, brass, bronze, aluminium, rubber, plastic, glass etc. that is non-magnetic. Then the crane moves to the designated spot where the iron is to be dumped. Then the electromagnet is OFF and the pieces drop - that is the beauty of soft magnetic materials like iron and electromagnetism. When the current is switched off the magnetism disappears and gravity takes over….
If we used a permanent magnet, the iron pieces would be picked up, but they would be stuck to the powerful magnet and removing them would be a tough task.
Explanation:
