CBSE Class 7 Science Electricity Assignment

I. Choose the correct answer:

1) Filament is made up of

a) Tungsten b) Aluminium c) Copper d) Tin

2) Resistance depends on

a) Material b) Thickness c) Length d) All of these

3) A length of wire wound closely together is called a

a) Resistance b) Coil c) Soft iron d) Fuse

4) The thin & coiled wire inside a bulb is called:

a) Terminal b) Filament c) Connecting wire d) Supportingwire

II. Fill in the blanks.

1) An electric cell has _________ terminals.

2) A group of connected cells is called a __________

3) A thin wire has a __________ resistance than a thick wire.

4) The lower the resistance, the _________ is the current.

5) The iron used in nails is called _______ iron.

III. State true or false.

1) Electric current flows through a closed circuit.

2) A long wire has a higher resistance than a short wire.

3) The higher the resistance, the lesser is the heat produced.

4) The greater the voltage across a device, the greater is the current through it.

5) Overload & short circuit cause minimum heating.

IV. Match the following.

            A                           B

1) Electromagnets    a) Plastic

2) Nichrome             b) Electric bell

3) Conductors          c) Heating element

4) Insulators             d) Metals

V. Define.

1) Current 2) Electric circuit 3) Circuit diagram 4) Resistance 5) Fuse 6) Coil 7) Eelectromagnet 8) Overload