write 3 to 4 uses of electromagnet
Answers
Loudspeakers and headphones.
Actuators such as valves.
Magnetic recording and data storage equipment: tape recorders, VCRs, hard disks.
Electromagnetism is one of the fundamental forces of the universe, responsible for everything from electric and magnetic fields to light. Originally, scientists believed that magnetism and electricity were separate forces. But by the late 19th century, this view changed, as research demonstrated conclusively that positive and negative electrical charges were governed by one force (i.e. magnetism).
Since that time, scientists have sought to test and measure electromagnetic fields, and to recreate them. Towards this end, they created electromagnets, a device that uses electrical current to induce a magnetic field. And since their initial invention as a scientific instrument, electromagnets have gone on to become a regular feature of electronic devices and industrial processes.
Electromagnets are distinguished from permanent magnets in that they only display a magnetic attraction to other metallic objects when a current is passed through them. This presents numerous advantages, in that the power of its magnetic attraction can be controlled, and turned on and off at will. It is for this reason that they are used extensively in research and industry, wherever magnetic interactions are called for.