In How to know, about science and technology series we will provide you information about science and technology, We are in making part of series and every part will contain 8-10 scientific questions and answer !
HOW DOES A DOORBELL WORK?
When you push a button to ring a doorbell, an electric current goes to the bell. The current powers a magnet in the bell, and the magnet moves a striker to hit the bell and make it ring. Some doorbells are not electric, but work by clockwork instead.
In a electric doorbell, the button is a switch that connects a supply of electricity to the bell. The current goes through a contact to an electromagnet. This produces a magnetic field that moves the striker, which hits the bell.
HOW DOES AN IRON WORK?
A hot iron smooths out creases in cloth. Most irons are powered by electricity. Inside the iron is an electric heater like an electric fire, but not so hot. A steam iron makes steam to make the cloth slightly damp. This helps to remove creases and wrinkles that a dry iron could not manage.
An electric iron has a heat control that sends more current to the heating element to make it hotter. A steam iron contains a water tank in which water is boiled by the heating element to make steam.
HOW DOES AN AEROSOL SPRAY WORK?
When you press down the nozzle of an aerosol can, a spray comes from the hole in the top. The spray in made of fine drops of liquid. Inside the can a gas under pressure forces the liquid up a tube to the top. When the top is pressed, the hole opens and the liquid sprays out.
The gas that is under pressure inside the can is called a propellant because it propels the liquid up the tube and out of the hole in the top. It consists of a gas that is harmless and does not dissolve in the liquid inside the can.
HOW DOES A VACUUM CLEANER WORK?
A vacuum cleaner sucks in air at one end, and as it does so, it sucks up dust and dirt. The dust and dirt are trapped in a bag inside the cleaner. The cleaner contains an electric motor which drives fans that suck in the air.
The vacuum cleaner may have brushes that stir up dust and dirt on the floor or in the carpet so that the cleaner can suck them in.
HOW DOES AN ELECTRIC LIGHT WORK?
A electricity goes through the switch to the light bulb. In the bulb is a thin wire called a filament. When electricity reaches the filament, it makes it hot, so hot that it glows with light.
The filament in a light bulb is made of tungsten. This metal has a very high melting point, so the filament does not melt when it gets white-hot. The bulb also contains a gas such as argon that does not combine with tungsten. If the bulb contained air, the oxygen would combine with the tungsten and the bulb would immediately burn out.
HOW DOES A TORCH WORK?
When you switch on a torch, electricity flows from the batteries inside the torch to the bulb, which lights up. Behind the bulb, a curved mirror reflects the light from the bulb so that a beam of light shines out.
The bulb in a torch is like an electric light bulb, except that it lights up with a low current of a few volts. This current is supplied by batteries. The batteries contain chemicals that produce an electric current when the torch is switched on.
HOW DO FUSES WORK?
Electric plugs have fuses for safety A These are small tubes that contain a thin wire. If too much electricity flows through the wire in the fuse, it could start a fire. If this happens, the wire melts. This cuts off the electricity before any damage is done.
The mains supply of electricity has a set of fuses where it enters a house. There are also fuses in plugs and in machines connected to the mains. These fuses melt and cut off the mains supply if the current begins to rise when an electrical appliance is in use.
HOW DOES THE TELEPHONE WORK
When you speak to someone on the telephone, an electrine signal goes from the mouthpiece, It travels along wires to the other telephone, There it works the earpiece so that the other person hears you The other person talks back to you in the same way.
The mouthpiece of a telephone contains a small microphone. The sound waves from your voice make a diaphragm vibrate and this compresses carbon granules in the microphone. An electric current flows through the microphone, and the granules vary its strength as you speak.
Also Read –
- Science And Technology Question & Answer – Part 1
- Science And Technology Question & Answer – Part 3
- Science And Technology Question & Answer – Part 4
- Science And Technology Question & Answer – Part 5
- Science And Technology Question & Answer – Part 6
- Science And Technology Question & Answer – Part 7
- Science And Technology Question & Answer – Part 8
- Science And Technology Question & Answer – Part 9
- Science And Technology Question & Answer – Part 10
- Science And Technology Question & Answer – Part 11
- Science And Technology Question & Answer – Part 12