CBSE Class 6 Science Chapter 12 : Electricity and Circuits Additional Questions

CBSE Class 6 Science 

Chapter 12 :  Electricity and Circuits

 Additional Questions

1. What are the uses of electric cells?
2. How many terminals does an electric cell have?
3. What is the structure of an electric cell?
4. Explain the structure of an electric bulb
5. Give the reason: We should not join the two terminals of the electric cell without connecting them through a switch and a device like a bulb.
6. What is the direction of the current in an electric circuit?
7. When we say that a bulb is fused? What is the reason for this?
8. What is a switch?
9. What is mean by conductors and insulators? Give examples
10. Why  do we get shock when we come in contact with electricity?
11. What are uses of conductors and insulators in day to day life?

Answers

1. Electric cells are used in torches, alarm clocks, wristwatches, transistor radios, cameras and many other devices 
2. An electric cell have two terminals. They are positive and negative terminal
3. Electric cells have a small metal cap on one side and a metal disc on other side. The metal cap is the positive terminal of the cell and the metal disc is the negative terminal. The positive and negative terminals are marked in the respective places of the cell.
4. The thin wire which glows and gives off light in the bulb is called filament. The filament is fixed to two thicker wires. The thicker wires give support to the filament. One of these thicker wires  is connected to the metal case at the base of the bulb, while the other thick wire is connected to the metal tip at the centre of the base. The base of the bulb and the metal tip of the base are the two terminals of the bulb and they are fixed in such a way that they do not touch each other.
5. If we join the two terminals of the electric cell without connecting them through a switch and a device like a bulb, the chemicals in the electric cell get used up very fast and the cell will not work.
6. The direction of current in an electric circuit is from the positive to the negative terminal of the cell.
7. We say that the bulb is fused, if it does not glow when it is connected to the cell. The main  reason for a bulb to fuse is a break in its filament, which cause the break in the path of the current.
8.  A switch is a simple device that either breaks the circuit or completes it. The switches used in lighting of electric bulbs and other devices.
9. The materials which allow electric current to pass through them are called conductors, where as the materials which does not allow electric current to pass through them are called insulators. Metals like Copper, Aluminium and Silver are examples of conductors, while glass, plastic, rubber, air wood etc are insulators.
10. We get shock when we come in contact with electricity because human body is a conductor of electricity.
11. Both conductors and insulators are useful for our day to day life. Conductors like copper is used to make wires and insulators are like plastic, rubber etc are used as wiring shields to protect us from the electric equipment.