Category Science

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.

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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.

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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.

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Why did Sir Isaac Newton stick a needle in his eye?

He did indeed. Or more accurately, he pushed a needle behind his eye and with it, indented the sclera. The needle never entered the eye.

By doing so, he stimulated his retina in many spots and noted a “phosphene” or glowing spot that resulted from the pressure. From this he was able to “map” his own retina against where he saw the spots. This map conformed to the map on the back of a rabbit’s retina that he made by shining light from a window, through a pinhole, into the rabbit’s eye that had an opening cut away from the sclera allowing him to see into the rabbit’s eye.

And thus Newton showed how the rays of light enter our eye by an optical system now called the camera design. And how the retina represents the outside world but with inversion (up is down and left is right).

Newton was a dedicated scientist who was willing to accept some pain and personal risk to satisfy his curiosity.

 

Credit : Quora

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Why do astronauts wear either white or orange?

The orange suits (affectionately called pumpkin suits) are not spacesuits. They are worn only while inside a vehicle that is ascending or descending through the atmosphere. Their primary purpose is to protect the crew member from the adverse effects of a depressurization inside the vehicle. They are orange because orange creates a high contrast against the background for rescue crews looking for the crew members in the water or on land.

The current white suits are spacesuits. They are designed for use outside the vehicle, in the vacuum of space. They are designed to provide a pressurized environment, thermal control, and protection against tears and punctures. The suits are white because of emittance. A spacesuit is a thermal system. It is therefore designed to balance the flow of heat into and out of the system. The heat from the Sun is part of the equation, but it is not the full equation. The human being and electrical equipment that is inside the suit is also producing heat and that (excess) heat needs to be rejected.

 

Credit : Quora

Picture Credit : Google