Try picking up the object with the electromagnet. Try changing the strength of the magnet by turning the knob. To lift a weight, the electromagnet must attract it with a force greater than the force of gravity.
More Electromagnets are common in many of our appliances.
Turning on your microwave involves the use of an electromagnet. Your doorbell rings because of electromagnets. Junkyards use giant electromagnets hanging on cranes to move huge pieces of metal from place to place. Even your TV uses electromagnets to scan the picture on the screen. In theory, much of the matter in the universe is magnetic - that is, able to exert a magnetic force.