NCERT Book Class 6 Science Chapter 9 Electricity and Circuits

9 Electricity and Circuits

W
e use electricity for many are also used in alarm clocks,
purposes to make our tasks wristwatches, transistor radios, cameras
easier. For example, we use and many other devices. Have you ever
electricity to operate pumps that lift carefully looked at an electric cell? You
water from wells or from ground level might have noticed that it has a small
to the roof top tank. What are other metal cap on one side and a metal disc
purposes for which you use electricity? on the other side (Fig. 9.1). Did you
List some of them in your notebook. notice a positive (+) sign and a negative
Does your list include the use of (–) sign marked on the electric cell? The
electricity for lighting? Electricity
makes it possible to light our homes,
roads, offices, markets and factories
even after sunset. This helps us to
continue working at night. A power station
provides us with electricity. However, the Fig.9.1 An Electric Cell
supply of electricity may fail or it may not
metal cap is the positive terminal of the
be available at some places. In such
electric cell. The metal disc is the
situations, a torch is sometimes used for
negative terminal. All electric cells have
providing light. A torch has a bulb that
two terminals; a positive terminal and a
lights up when it is switched on. Where
negative terminal.
does the torch get electricity from?
An electric cell produces electricity
9.1. ELECTRIC CELL from the chemicals stored inside it.
Electricity to the bulb in a torch is When the chemicals in the electric cell
provided by the electric cell. Electric cells are used up, the electric cell stops

Caution You might have seen the danger sign shown here displayed on poles,
electric substations and many other places. It is to warn people that
electricity can be dangerous if not handled properly. Carelessness in
handling electricity and electric devices can cause severe injuries and
sometimes even death. Hence, you should never attempt to experiment
with the electric wires and sockets. Also remember that the electricity
generated by portable generators is equally dangerous. Use only electric
cells for all activities related to electricity.

ELECTRICITY AND CIRCUITS 95