Electromagnet.
A piece of iron wrapped by enamel-coated copper wire forming a coil. This piece of iron temporarily becomes a magnet when an electric current passes through coil. Such a magnet is called Electromagnet.
Making an electromagnet.
Take approximately 6-10 cm long iron nail and a 50 cm plastic coated wire. Wrap the wire around the iron nail in the form of a coil. Connect the independent ends of the wire to the terminals of the power cell through the switch as shown in the figure.
Turn the switch on and now bring some pins closer to the end of the nail. You will notice that the pins are pulled towards the nail, because the coil behaves like a magnet when an electric current passes through it. An iron nail lies in this magnetic field also becomes a magnet. When the flow of electric current ceases the magnetic effect of the coil and then of the nail disappears. This coil-nail setup becomes an electromagnet.
Factors Affecting the Power of Electromagnetism:
- Strength of electric current.
- The number of turns of wire wrapped around the iron nail.
Uses of electromagnets:
- To lift heavy iron objects and to separate the magnetic material from the heap of scrap: a strong electromagnet is placed at one end of the crane.
- Electromagnets are also used in many toys.
- Doctors use an electromagnet to remove a small piece of magnetic material that may have entered the eye of a worker accidentally.
- It is also used in many devices: such as an electric bells, telegraphs, telephones, speakers, etc.
