Lead of a pencil is

1

(a)

a insulator

(b)

a conductor

(c)

a semiconductor

(d)

None of these

Filament of a torch bulb is

1

(a)

a metal case

(b)

metal tip at the centre of the base

(c)

two thick wires

(d)

a thin wire

Our body is

1

(a)

a bad conductor of electricity

(b)

sometimes a good conductor and sometimes a bad conductor

(c)

a good conductor of electricity

(d)

None of the above

Rubber is a

1

(a)

conductor

(b)

insulator

(c)

semiconductor

(d)

None of these

In bulb,_______________ glows.

1

(a)

filament

A device which makes or breaks the circuit is called _________________

1

(a)

switch

The electric cell and bulb have__________________ terminals.

1

(a)

two

Materials that allow the electricity to pass through them are called ___________________

1

(a)

conductors

A car battery contains many cells.

1

(a) False

(b) True

Air conducts electricity.

1

(a) True

(b) False

Paheli wanted to glow a torch bulb using a cell. She could not get connecting wires instead she got two strips of aluminium foil. Will she succeed? Explain how.

2

(a)

State the purpose of using of an electrical switch

2

(a)

We should use plastic gloves for operating electrical devices. Explain why

2

(a)

Mention what type of materials can be used in electric circuit so that the current can pass through them.

2

(a)

Paheli has another arrangement of the cell and the bulb. Will the torch bulb glow in the following arrangement?

2

(a)

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

3

(a)

A torch is not functioning, though contact points in the torch are in working condition. What can be the possible reasons for this? Mention any three.

3

(a)

You are provided with a bulb, a cell, a switch and some connecting wires. Draw a diagram to show the connections between them to make the bulb glow.

3

(a)

Discuss briefly that how switch works.

3

(a)

Briefly explain about the components present inside the cell.

3

(a)

A torch requires 3 cells. Show the arrangement of the cells with a diagram inside the torch so that the bulb glows.

5

(a)

If we touch a base wire and we are in contact with earth, then we can get an electric shock and if we are standing above a plastic or drywood chair, then even on touching the base wire, we will not get any electric shock. Explain why.

5

(a)

With the help of a labelled diagram, explain the structure and function of a torch?

5

(a)