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.