Arjun Nair - Science Behind Radio

How can you calculate the aspects of electricity such as voltage, current, resistance?

Well most ways to calculate is by formulas, but there is a very famous formula and simple invented by a man named Ohm therefore the formula is called Ohm’s Law. Ohm’s Law-V=I x R

Example. I is 40 amps and R is 10 ohms therefore V is 40 x 10 therefore V=400 volts and you can also change it around so if you want to find the current of a circuit. V is 4 and the R is 16 .The steps would be:

An I.C is an integrated circuit that is simply a very big complex circuit that is the size of your hand! The history of I.C started with the modern marvel the transistor. An I.C'S also has a lot of pins, which are inputs you connect to for the I.C to do something; an I.C‘s pins can range from 5 to 30!

Electrons are – charged so electrons get attracted by + so from - to +. Also electrons are lazy, so the take the fastest and easiest way to get to the + terminal of a battery.

Chemical reactions that produce electrons are called electrochemical reactions. Any battery has 2 terminals. One terminal is marked (+), or positive, while the other is marked (-), or negative. In an AA, C or D cell (normal flashlight batteries), the ends of the battery are the terminals. In a large car battery, there are two heavy lead posts that act as the terminals. Alessandro Volta created the first battery in 1800. To create his battery, he made a stack by alternating layers of zinc, blotting paper soaked in salt water, and silver, like this:

This arrangement was known as a voltaic pile. The top and bottom layers of the pile must be different metals, as shown. If you attach a wire to the top and bottom of the pile, you can measure a voltage and a current from the pile. The pile can be stacked as high as you like, and each layer will increase the voltage by a fixed amount. Sulfate metal in this case is when a metal is taken and is combined or treated with sulfuric acid. The different metals on the bottom and top resembles the + and – terminals of today’s AA batteries.

A connection between an electrical device and the earth (which is at zero voltage)

Early developers of electrical systems theorized that the earth was an electrically neutral body, i.e. an equal number of negative and positive charges are distributed throughout the earth at any given time. Being electrically neutral, earth is considered to be at zero potential (the building up to capacity for when released as kinetic energy) and establishes a convenient reference frame for voltage measurements. Noting that voltmeters read only the difference in potential between two points, absolute measurements can be made by using earth as a reference because a voltmeter reads makes the measurement between two points, but by using the ground witch is at 0 any current flowing will change the reading at ground, so electricians can see what is the voltage.

A true earth ground, as defined by the National Electrical Code, physically consists of a conductive pipe or rod driven into the earth to a minimum depth of 8 feet. Ground is most commonly used in things to do like a radio transmitter cable lines and telephone lines.

In this diagram start at the energy source (eg. Enmax Heating) then follow the power line to the right and you will end at the load (eg. Arjun heating the house up on the thermostat and using the heat given by Enmax) then the current goes to the conductive pipe that is driven into the earth eight feet, then the current travels through the ground and is picked up at the other conductive rod witch is also driven into the earth 8 feet goes up the pipe and follows the power line back to the energy source. The reason why they have those big steel structures all around because those structures are like a check stop for the electric current and to make sure the current is not less or more if it gets those readings it either means there is a break some where in the power line or a short circuit is there. The reason why it has to be 8 feet or more under the earth’s surface because it is at 8 feet or less that the wires carrying the current wont disturb crops, back yards etc. at surface level. [7]

A short circuit is an abnormal electrical path. If the current goes somewhere you do not want it go the results could be destructive. To avoid that you put in a fuse. A fuse will take the damage instead of it going booom in your face.

The main job of the fuse is to protect the wiring. Fuses should be sized and located to protect the wire they are connected to. If a device like your car radio suddenly draws enough current to blow the fuse, the radio is probably already toast. The fuse is there to protect the wire, which would be much harder to replace than the radio. The inside of a wire can get very hot if the current is a lot. In a fuse a wire goes through it and if the inside of the wire is hot due to the high current, the fuse has a mechanism that reacts to that heat and the fuse blows witch breaks the circuit, this feature stops the high current causing disaster.

A wire is used to carry current. It can carry current because inside a wire is a type conductor such as copper is placed and is covered in an insulator so that the current cannot escape and so that if you are handling wire you do not get shocked. If too much current goes through a wire, it can overheat and melt. The amount of current that a wire can handle depends on its length, composition, and size and how it is bundled. Let's take a quick look at how each of these properties affects the wire's current-carrying capacity:

Length - Each type of wire has a certain amount of resistance per foot -- the longer the wire, the larger the resistance. If the resistance is too high, a lot of the power that flows down the wire will be wasted.

Composition - Automotive wire is usually composed of fine copper strands. Generally, the finer the strands, the lower the resistance and the more current the wire can carry. The type of copper used has an effect on the resistance of the wire, too.

Wire gauge - The wire gauge, or size of the wire, also determines how much resistance the wire has. The larger the wire, the lesser will be the resistance. The smaller the gauge, the larger the wire -- so a 16-gauge wire is bigger than a 24-gauge wire

Bundling - The way a wire is bundled affects how well it can dissipate heat. If the wire is in a bundle with 50 other wires, it can carry a lot less current than if it were the only wire in the bundle.

A cable is two or more wires bound together which may be bare or covered or insulated. Also a cable is a type of wire used to connect computers to networks. CAT–5 cables are the type people can now use to connect computers to the network. A cable is also used for television.

Solar power is the technology of obtaining usable energy from the light of the Sun. Solar energy has been used in many traditional technologies for centuries and has come into widespread use where other power supplies are absent, such as in remote locations and in space. The sun’s energy can provide 1000watts per meter on the earth’s surface

Solar cells, also referred to as photovoltaic cells, are devices or banks of devices that use the photovoltaic effect of semiconductors to generate electricity directly from sunlight. Until recently, their use has been limited because of high manufacturing costs. One cost-effective use has been in very low-power devices such as calculators with solar cells. Another use has been in remote applications such as roadside emergency telephones, remote sensing. A third use has been in powering orbiting satellites and other spacecrafts.

This is a picture of where you can find where solar panels would be effective and where it would not be useful.[9]

The electromagnetic spectrum is a vast band of energy frequencies extending from radio waves to gamma waves, from the very lowest frequencies to the highest possible frequencies.
The spectrum is arranged by the frequency of its waves, from the longest, lowest energy waves to the shortest, highest energy waves.
Our ability to tune in the more exotic electromagnetic waves has grown in recent decades. For instance, radio is part of the spectrum, and it was only in the 20th Century that humans began to be able to use any of the electromagnetic spectrum, starting with radio at the long-wave end of the spectrum.
Today, living and working in the 21st century, we make great use of the electromagnetic spectrum in all of our vocations and avocations. All of the frequencies we use for transmitting and receiving energy are part of the electromagnetic spectrum. For instance:

RADIO We use the radio portion of the electromagnetic spectrum for many things, including television and radio broadcasting, telephones and other wireless communications, navigation and radar for a variety of measurements including police speed traps, and even microwave cooking ovens.
Our AM broadcast stations transmit signals in what is referred to as the medium-wave portion of the spectrum. FM music stations use very high frequency (VHF) transmitters. Television stations use the VHF and ultra high frequency (UHF) regions of the spectrum.

INFRARED LIGHT Infrared light is on the spectrum at frequencies above radio and just below the range of human vision. Infrared light is heat. Three-quarters of the radiation emitted by a light bulb is IR. We use infrared transmitters to remotely control our TV sets.

VISIBLE LIGHT Visible light, which we receive with our eyes, is along the spectrum between infrared and ultraviolet light, which we can't see. Of course, we can collect visible light with photographic film.[11]

Visible light, however, covers only a small part of the range of wavelengths in which electromagnetic waves can be produced. Radio waves are electromagnetic waves of much greater wavelength than those of light.

For centuries, astronomers learned about the sky by studying the light coming from astronomical objects, first by simply looking at the objects, and later by making photographs. Many astronomical objects emit radio waves, but that fact wasn't discovered until 1932. Since then, astronomers have developed sophisticated systems that allow them to make pictures from the radio waves emitted by astronomical objects.

Planets in our solar system, chemicals in comets and in the Milky Way Galaxy, supernovae, and, emit radio waves by other galaxies and distant quasars. These radio waves travel through space just like light, and radio telescopes can intercept them. Astronomers often convert these signals into pictures. Here are three "radio pictures" showing:

.
A supernova remnant	The moon	A galaxy

They look like photographs don't they? But radio waves are invisible! So, how do scientists make "radio pictures" of the objects in the Universe?

Radio telescopes look like this. The dish of a radio telescope is made of metal and has a parabolic shape. Radio waves emitted by that object hit the surface of the dish, and bounce. Because the dish is shaped the way it is, those waves all bounce up to the tip of the telescope, the focal point. The radio waves are focused there. At the focal point, the radio waves enter a sensitive receiver. The receiver amplifies the waves and converts them into a signal that can be stored in a computer. Astronomers use computers to turn this information into pictures. If our eyes were designed to see radio waves instead of light, the picture is what we would see. [5][9]

Things you ought to know