(a) Circuit Diagram

(b)Two possible reasons:
(i) Switch is in OFF position.
(ii) Filament of bulb gets broken.

(i) The wire gets hot when electric current passes through it. This property of electric current is called as heating effect of current.
(iii) Electric Bulb and Hair Dryer
(iii) Electric Fuse

When current was passed through a wire around a compass needle, H.S. Oersted concluded.
(a) When an electric current is passed through a wire, it behaves like a magnet.
(b) The magnitude of magnetic field increases with the intensity of current.
(c)The induced magnetic field is at right angles to the direction of the flow of electric current

Electric heater and ironwork on the basis of heating effect of electricity. When an electric current passes through the wires they become hot. Electric heater or iron contains a coil of wire. This coil of wire is called an element. When these appliances are switched on after connecting to the electric supply, their elements become red hot and give out heat.

An electric bulb is used for light but it also gives heat. This is not desirable. This results in the wastage of electricity. This wastage can be reduced by using fluorescent tube lights (CFLs)in place of the bulbs. CFLs are also used to reduce wastage of electricity. There are compact fluorescent lamps. These can be fixed in ordinary bulbs holders.

Fuse is a safety device which prevents our houses, appliances and electric circuit from electrical hazards at the time of the short circuiting or overloading. The fuse works on the basis of heating effects of the electric current. If, by an accident the current exceeds a certain limit this device becomes overheated and melts which breaks the circuit and supply of electricity is stopped. In this way, it helps in prevention of short circuits

The cell is the unit of battery when more than one cell are combined together, it forms a battery. In trucks, tractors and inverters, cells are internally arranged and we need not to connect it externally, so we called it as batteries.

When an electric current is passed through a coil, it gets magnetised due to phenomena of magnetic effect of current. When magnetic materials such as pins are placed near to it. It gets attracted by the coil or we can say that pins cling to the coil.

If we connect more of cells in the circuit, then the nail will attract more pins. It is due to the reason that the current flowing through the wire wound on the nail will get increase which in turn will increase the strength of the electromagnet.

No, we cannot use same fuse in a geyser and in a television set because the fuse used in every appliances has some limit to withstand the current flows through it. So, different appliances have different fuses.

We do cover plug pinholes which are within the reach of children with cellotape or plastic cover to avoid electric shocks. If unconsciously, a child puts his finger in the electric socket, the shock may be fatal.

(a) Heating effect of current is used in electric heater and geyser.
(b) Magnetic effect of current is used in electric bell and cranes to lift heavy magnetic materials from one place to other.

Yes, the compass needle shows the deflection, when switch is closed or circuit is complete. On closing the circuit, current flows through the coil and it gets magnetised. Thus, due to this magnetic effect of current, compass needle shows deflection.

When the current is switched ON through a wire or a coil, there is a magnetic field created around the coil or wire and we can say that the wire or coil gets magnetised. Thus, a compass needle kept nearby gets deflected from its North-South position due to other magnet formed by current carrying wire or coil.

The two effects of electric current are
(i) Heating effect
(ii) Magnetic effect