NCERT Solutions for Class 6 Science Chapter 12

1. In an electric bulb, light is produced due to the glowing of
(a) the glass case of the bulb.
(b) the thin filament.
(c) the thick wires supporting the filament.
(d) gases inside glass case of the bulb.
2. Filament of a torch bulb is
(a) a metal case.
(b) metal tip at the centre of the base.
(c) two thick wires.
(d) a thin wire.
3. Choose the incorrect statement.
(a) A switch is the source of electric current in a circuit.
(b) A switch help to complete or break the circuit.
(c) A switch helps us to use electricity as per our requirement.
(d) When the switch is open there is an air gap between its terminals.
4. Paheli is running short of connecting wires. To complete an electric circuit, she may use a
(a) glass bangle. (b) thick thread. (c) rubber pipe. (d) steel spoon.

5. When the chemicals in the electric cell are used up, the electric cell stops producing electricity. The electric cell is then replaced with a new one. In case of rechargeable batteries (such as the type used in mobile phones, camera and inverters), they are used again and again. How?
6. Why do bulbs have two terminals?
7. 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?
8. 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.

1 (b)
2 (d)
3 (a)
4 (d)
5. Rechargeable batteries can be recharged by providing them appropriate current.
6. Bulb has two terminals to connect the filament with the circuit so that the current can pass through it.
7. Yes. Aluminium foils can act as connecting wires.
8. The possible reason could be
(i) the bulb may be fused. (ii) the cells may have been used up. (iii) the cells are not placed in the correct order. (iv) the switch is faulty.