CBSE Class 6 Science Chapter 12 : Electricity and Circuits, NCERT Solutions

CBSE Class 6 Science 

Chapter 12 :  Electricity and Circuits

 NCERT Solutions

1. Fill in the blanks :

(a) A device that is used to break an electric circuit is called _______________.

Answer:
Switch

b) An electric cell has _______________ terminals.

Answer:
Two

2. Mark  'True' or 'False' for following statements:

(a) Electric current can flow through metals.

Answer:

True

(b) Instead of metal wires, a jute string can be used to make a circuit.

Answer:

False

(c) Electric current can pass through a sheet of thermo Col.

Answer:

False

3. Explain why the bulb would not glow in the arrangement shown in Fig. 12.13.

Answer:
The bulb will not glow in this arrangement. A tester/ screw driver is connected in the circuit. Since one end of the tester/screw driver is made up of material which does not conduct electricity, the current does not passes through this circuit and hence the bulb will not glow

4. Complete the drawing shown in Fig 12.14 to indicate where the free ends of the two wires should be joined to make the bulb glow.

Answer:

5. What is the purpose of using an electric switch? Name some electrical gadgets that have switches built into them.

Answer:

Electric switch is a simple device, which is used to break or complete the circuit. Appliances like table fans, TV, radio, washing machine etc have switches built in them.

6. Would the bulb glow after completing the circuit shown in Fig. 12.14 if instead of safety pin we use an eraser?

Answer:

The bulb will not glow if we use an eraser, because eraser is an insulator which does not conduct electricity.

7. Would the bulb glow in the circuit shown in Fig. 12.15?

Answer:

In this diagram, the electric circuit is closed and the bulb will glow.

8. Using the "conduction tester" on an object it was found that the bulb begins to glow. Is that object a conductor or an insulator? Explain.

Answer:

The object is a conductor of electricity. Since the object is good conductor or electricity, the current passes through the conduction tester and the bulb glows.

9. Why should an electrician use rubber gloves while repairing an electric switch at your home? Explain.

Answer:

Rubber is an insulator, which does not allow electric current to pass through them. Hence electrician uses rubber gloves while repairing to save himself from electric shock

10. The handles of the tools like screwdrivers and pliers used by electricians for repair work  usually have plastic or rubber covers on them. Can you explain why?

Answer:

Both plastic and rubber are insulators, which does not allow electric current to pass through them. Hence the handles of the tools like screwdrivers and pliers are made with plastic or rubber to avoid electric shock.

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.

CBSE Class 6 Science Chapter 12 : Electricity and Circuits Fill in the blanks

CBSE Class 6 Science 

Chapter 12 :  Electricity and Circuits

 Fill in the blanks

1. Electricity to the bulb in a torch is provided by --------------
2. In an electric cell, the metal cap is the -----------terminal whereas metal disc is -------terminal
3. An electric cell produces electricity from the -------------- stored inside it.
4. The thin wire that gives off light in a bulb is called ------------- of the bulb
5. In an electric circuit, the direction of current is from ---------------- terminal to ----------terminal of the electric cell
6. A ----------- is a simple device that either breaks the circuit or completes it
7. -------------- do not allow electric current to pass through them. 
8. Air is an example for ------------.
9. Switches, electrical plugs and sockets are made of -------------------.
10. An electric bulb glows when ----------------------- passes through it

Answers

1. Electric cell
2. Positive, Negative
3. chemicals
4. filament
5. Positive, Negative
6. Switch
7. Insulators
8. Insulator
9. conductors
10. electric current