Know More..

Category Electricity

Where nuclear power is used to generate electricity in Europe?

An important world record in the field of nuclear science is held by Britain, where the world’s first atomic power station was built in 1956 at Calder Hall.

Since then, the generation of electric power by atomic or nuclear reactors has become increasingly important in Europe, where over 10 percent of total generating capacity is now nuclear. This is a higher proportion than in any other continent.

The leading European nuclear country in terms of nuclear power stations is France, which generates about a third of its electricity from nuclear fuels. Then come Germany, Britain, Sweden, Finland, Spain, Switzerland, Belgium, Bulgaria, Italy, Czechoslovakia, Yugoslavia and The Netherlands.

British nuclear power stations use a variety of different kinds of reactors, including an experimental fast breeder reactor at Dounreay. This is a kind of reactor that produces more fuel than it consumes and it could in theory generate immense amounts of power in the future.

However the technological problems involved have proved extremely difficult to solve and it is now doubtful whether the fast breeder will ever fulfil its early promise. Although nuclear power stations have to date worked well and safely throughout Europe, there is a mounting problem of radioactive waste disposal.                                                                                                                                                                                                          

 

Picture Credit : Google

Are Electricity and Electronics different?

Electricity in a wire creates the pushes and pulls that get work done. It lights lamps and runs machines. But electricity has another important use. It can carry information. Thanks to electricity’s ability to carry information, we have tiny radios, handheld calculators and video games, and personal computers.

The use of electricity to carry electric signals is called electronics. These electric signals may stand for sounds, pictures, numbers, letters, computer instructions, or other sorts of information.

An electronic device has many tiny electrical pathways called circuits. Each circuit has a special job. Some circuits store signals. Others change signals. For example, in an electronic calculator, one circuit might add two numbers together. When the answer is reached, another circuit sends a signal that light up a display screen to show the answer.

The circuits in most of today’s electronic devices are mounted on a chip, a piece of material that is no bigger than a fingernail.

Picture Credit : Google

What is Electromagnet?

Electricity can make light and heat. It can also make a magnet. But this is a magnet you can turn on and off.

A magnet made with electricity is called an electromagnet. An electromagnet has two parts. The first part is a solid centre, or core, made of iron. The second part is an outer covering made of wire that is coiled many times around and around the solid iron core.

When an electric current runs through the wound wire, the iron becomes a magnet. The iron gets its pull, or magnetism, from the moving electrons in the wire. As soon as the electric current is turned off, an electromagnet loses its magnetism.

Electromagnets are used to make electric motors run. A motor has two sets of these magnets – an outer set that stays in place and an inner set that moves. The inner set of electromagnets is attached to an axle – a rod that can spin. When the motor is turned on, the two sets of electromagnets push and pull against each other. That push makes the inner magnets move and spin the axle. And the spinning axle gives a push that makes the motor run.

Picture Credit : Google

How can we store Electricity?

A torch runs on electricity, but you don’t have to plug it in. It carries its own electric current in a “package” – a battery.

A battery is made of layers of chemicals inside a metal container. When the torch is turned on, some of the chemicals in the battery break apart and eat away at the metal container. As this happens, some of the metal atoms leave the container and combine with the chemicals inside the battery.

As the metal atoms move away from the container, they leave some of their electrons behind. So the container gains electrons. And as the chemicals inside the battery break apart, they lose electrons.

Soon, there are more electrons in the container than there are inside the battery. Then the extra electrons in the container begin to move out of the battery. They travel through the bulb and back into the middle of the battery, where electrons are scarce. The push of these electrons is the current that makes your torch shine.

It may sound as if everything happens very slowly, but, as you know, it all takes place in an instant.

Picture Credit : Google

What is the function of Switch in a circuit?

You want your electric clock to run day and night. But you wouldn’t want your doorbell ringing all the time. Things like doorbells, lamps, and radios work only when you turn them on.

Most things that run by electricity have a switch. A switch is used to turn the electric current on and off. The electric current moves along the wire and across the switch to another wire inside the bell, lamp, or radio. The switch is a “bridge” in the path the electricity follows.

A metal piece inside the switch moves when you turn the switch on and off. When you turn the switch on, the metal piece touches both wires. The “bridge” is down. The electricity coming into the switch can cross the “bridge” and keep travelling along the pathway.

When you turn the switch off, the metal piece moves away from the wire. The “bridge” is up. Without the “bridge,” the electric current can’t cross the switch and follow the path. So, the electric current stops moving, and things stop working until you lower the “bridge” in the pathway by turning the switch on again.

Picture Credit : Google

What should I know about Electricity?

 

ELECTRICITY

One of the most useful forms of energy in today’s world is electricity. It is transportable, which means it can be carried long distances by wires and cables. It is convertible, being changed into many other forms of energy, such as light from an electric light-bulb, and movement in an electric motor. It is also controllable. We can turn it on and off with a switch, or up and down with a knob. When a city suffers a power cut and falls still and silent, we realize how much we depend on electricity.

Electricity is the movement of electrons, the negative particles around the nucleus of an atom. Most metals, especially silver and copper, have electrons that can move easily from atom to atom, so they are good carriers or conductors of electricity. Electrons are pushed along the conductor by a battery or generator. But they flow only if they have a complete pathway of conductors called a circuit. Flowing electricity is known as electric current.

In substances such as rocks, wood, plastics, rubber and glass the electrons do not move easily. These materials prevent the flow of electricity and are known as insulators, but they may gain or lose electrons on their surface as a static electric charge.

            Static electricity is produced when electrons are separated from their atoms. On a comb it attracts bits of paper. In the sky it causes lightning!

            Electric current flows along a wire as electrons which detach from the outermost parts of their own atoms and jump or hop along to the next available atoms.

Picture Credit : Google

How they make bulbs from a ribbon of glass?

Making light bulbs is an intricate and highly automated factory process in which the bulbs are blown into shape in moulds from a continuous ribbon of molten glass.

A vital component of the bulbs is the filament, a coil of tungsten wire one hundredth of a millimetre thick. This is the part that becomes white hot and produces the light when electricity flows through. It is mounted on a glass time stem and clamped to the end of thicker wires that pass through the stem of the base of the bulb.

When the stem is inserted in the bulb, any oxygen in the bulb is eliminated (otherwise it would cause the coil to oxidise, greatly reducing its life). The bulb is then filled with an argon/nitrogen mixture. It is sealed and a metal is cemented in place.

A modern bulb-making machine can produce 30 bulbs in a few minutes, each able to pour out light for at least 1000 hours. Gradually, however, the metal filament evaporates. Eventually it will break and the light will fail.

Whistling bulbs

Why do some bulbs whistle before they fail? In fact, the filament breaks while the bulb is alight, but it stays alight because electricity arcs over the gap. It is the arc that emits the high-pitched whistle.

 

Picture Credit : Google

Why paper-thin bulbs are so strong?

The glass of an electric light bulb is not much thicker than the paper of this page, yet it with stands a strong grip when you push it into a light fitting. The explanation for this lies mainly in the in the bulb’s shape, which exploits the eggshell principle.

Aeons ago, nature found a solution to the problem of preventing eggs from being crushed by the weight of the hen bird as she sat on the nest to incubate them. The solution was the characteristic egg shape, which provides structural strength, to withstand all-round pressure even with a thin shell. (If the shell were too thick, the chick inside would not be able to peck its way out.)

Light bulbs (and eggs) have a rounded profile over the whole surface. When you grip a bulb, the force you apply is transmitted in all directions away from the point of contact by the curve of the glass.

This results in the force being distributed over a wide area, and no excessive stress being set up at any one point.

 

Picture Credit : Google

How does the sun turn city lights on and off?

At dusk and dawn, millions of street lights are turned on and off throughout the world every day  – many of them by the light of the sun its self.

Most lights are controlled by time switches, which operate a group of lights in nearby streets. The earliest time switches worked by clockwork and had to be wound up and adjusted every week.

Many modern time switches now have an electric clock with a rotating dial, containing levers or tappets, which turn the lights on or off at the chosen times. They are similar to many times switches on air-conditioning systems.

Since the sun rises and sets at different times throughout the year, street lights must also go on and off at different times, so these dials also alter the switching times according to the season of the year.

This is arranged in the time switch by a mechanical device which adjusts the ‘On’ and ‘Off’ tappets month by month to follow the changes in the hours of daylight.

Recently, street lighting engineers have developed a photoelectric control unit called ‘pecu’, which operates a switch in the electrical supply to the lights.

A photocell in the unit contains a light sensitive compound such as cadmium sulphide or silicon. At dawn, light falling on the photocell causes electrons to flow from one atom to another, conducting electricity to the switch and turning it off. When darkness falls, the electrons in the compound became immobile, the current stops, and the lights are turned on. The exact time that the current is switched on and off depends on the weather conditions.

 

Picture Credit : Google

How to create Neon light effects?

Neon lights create gaudy pictures and spell out brand names on advertisements the world over.

Unlike the traditional electric light bulb, neon lights in the form of thin tubes can easily be shaped into lettering and other intricate outlines.

To produce their distinct take light, they exploit what is called electric discharge through gases. Ordinarily, gases do not easily conduct electricity – they are good insulators. They can, however, be made to conduct electricity if their pressure is to

lowered and high voltage is applied.

In the light 19th and early 20th centuries, scientist investigating electric discharge through the rare gas neon at low pressures, first observed the striking red-orange glow the gas is given out.

To create neon light, electricity is applied to the ends of a glass tube filled with neon. Atomic particles called electrons stream from one end of the tube to the other, and on their way they collide with atoms of neons. As a result of the collisions, electrons orbiting within the neon atoms are knocked out of orbit. They acquire extra energy from the impacts, just as a billiard ball acquires energy when struck by another. As they return to their original orbit, they give out their surplus energy as electromagnetic radiation.

This radiation has a frequency which lies in the visible light range and you see it as a brilliant red-orange glow.

When other gases are used in tubes, a similar process occurs. But the electrons give off radiation at different frequencies, which you see as different colours. Helium gives a golden-yellow light and krypton a pale violet. Other colours are produced by fluorescent materials in tubes containing mercury or argon, sometimes in combination with coloured glass.

 

Picture Credit : Google