If one pole of a bar magnet is brought near small iron nails, they form a chain as shown in the figure below.
The magnetised nail is attracted to the magnet and clings to it. This magnetised nail, in turn, magnetises the neighbouring nail through induction and attracts it. This process continues until the force of attraction on the first nail balances the weight of all the nails in the chain below it. If the uppermost nail is held in position by fingers and the magnet is removed, all the nails fall down. This is because, without the magnet, the uppermost nail loses its magnetism. The nails no longer attract each other and separate, falling down due to gravity. This demonstrates that induced magnetism is temporary and lasts only as long as the magnet causing the induction is nearby.