7. Few iron nails and screws got mixed with the wooden shavings while a carpenter was working with them.How can you help him in getting the nails and screws back from the scrap without wasting his time in searching with his hands?

Ans: With the help of a magnet we can attract all iron nails and screws and can separate them from the wooden shavings. As iron nails and screws are magnetic materials and will get attracted to the magnet,whereas wooden shavings are non-magnetic.