What does current electricity do?
Current electricity is the most important source of energy in our life. It can do many things. Some of those are mentioned below
I. Electricity makes a light glow:
An electric bulb has a very thin coiled wire in it. It is called filament. When electricity flows through this filament, it becomes very hot and glows brightly to emit light.
II. Electricity can generate heat:
Let us prepare a tube, 30 cm long, with card-board having a diameter of a big torch. Collect four to five numbers new torch batteries. Set those batteries in the card-board tube, placing one after another in same direction. Collect a 10 to 15 cm piece of electrical wire. Peel it off completely and take only one very fine hair-like core wire from it. Collect a long pin-like object and wind that bare copper wire around it. On removal of the pin we will get a miniature form of a copper- wire spring. Now join the two ends of the spring to two terminals of the battery set with two electrical wires and let the current flow for few minutes. After that if you touch the copper spring, it will be felt very hot. We utilize this property of current electricity in electric heater, oven, water heater, electric iron, etc. in our daily life.
III. Electricity generates magnetic power:
Let us prepare a magnet with electricity. For that take a long nail made of iron. Collect a two feet long insulated copper wire and peel off its two ends. Coil it around the nail. Connect and fix the two open ends of the wire to two poles of a new torch battery with a rubber band. Now hold a few paper pins near the nail and observe that the nail will attract the paper pins. If we disconnect the current supply from the battery, the nail will immediately lose its magnetic effect and will release the pins. This experiment proves that when electric current flows through the wire a magnetic field develops to make the nail temporary magnet.
Electromagnets are used in door bells, telephone receivers, speakers, at factory scrap yard etc. In eye surgery also, electromagnets are used to remove small iron filings from eye.