Final answer:
Electromagnets are devices that create a temporary magnetic field using electric current and are used in electric motors, earphones, and to lift heavy steel objects in junkyards.
Step-by-step explanation:
Electromagnets are used in electric motors, earphones, and in junkyards to lift old cars and other heavy steel objects. Hans Christian Oersted's discovery that a compass needle was deflected by a current-carrying wire led to the understanding that electrical currents cause magnetic effects, establishing the fundamentals of electromagnetism. By using electric current to create magnets, electromagnets serve versatile roles—from lifting scrapped cars in wrecking yards to controlling beams in particle accelerators and operating medical imaging machines.
An electric motor is a common application of this technology, where loops of wire in a magnetic field experience torque when current is passed through them. This torque rotates a shaft, converting electrical energy into mechanical work. Other uses of electromagnetism include manipulation of eddy currents which have practical applications like metal detectors, braking systems in trains, and induction cooktops.