NCERT Class 6 Science Chapter 12 Electricity and Circuits

Chapter 12 Electricity and Circuits

Question 1: Fill in the blanks:
a) A device that is used to break an electric circuit is called _______________.
b) An electric cell has _______________ terminals.
Answer:
a) A device that is used to break an electric circuit is called switch.
b) An electric cell has 2 (negative and positive) terminals.

Question 2: Mark 'True' or 'False' for following statements:
a) Electric current can flow through metals.
b) Instead of metal wires, a jute string can be used to make a circuit.
c) Electric current can pass through a sheet of thermo Col.
Answer:
a) True
b) False
c) False

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

Answer: The bulb would not glow in the arrangement because circuit is not complete as there is an insulator in the circuit. To make the bulb glow, there should be the conductors through which electricity can pass.

Question 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:

Question 5: What is the purpose of using an electric switch? Name some electrical gadgets that have switches built into them.
Answer: The purpose of an electric switch is to complete or break the circuit. Electrical gadgets that have switches built into them are refrigerator, television, microwave oven.

Question 6: Would the bulb glow after completing the circuit shown in Fig. 12.14 if instead of safety pin we use an eraser?
Answer: No, the bulb will not glow as eraser is an insulator.

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

Answer: No, the bulb will not glow.

Question 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 because the bulb glows only when the conductor is used but not when the insulator is used.

Question 9: Why should an electrician use rubber gloves while repairing an electric switch at your home? Explain.
Answer: An electrician uses rubber gloves while repairing an electric switch at your home because rubber gloves are insulators. And insulators will prevent the electric shock.

Question 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: Plastic or rubber is an insulator which does not allow electric current to pass through it. The handles of the tools like screwdrivers and pliers used by electricians for repair have covering of plastic or rubber so that electric current may not pass through these tools.