katyzzzElectricity and working
August 24th 2006 22:47
Electricity and working :
Electricity completely surrounds us -- For most of us, modern life would be impossible without it. Here are just a few examples:
Throughout your house, you probably find electrical outlets where you can plug in all sorts of electrical applicances.
Most portable devices contain batteries, which produce varying amounts of electricity depending on their size.
During a thunderstorm, there are huge bolts of electricity called lightning that shoot down from the sky.
On a much smaller scale, you can get a shock from static electricity on dry winter days.
It is easy to create electricity from sunlight using a solar cell; or you can create electricity from the chemical energy in hydrogen and oxygen using a fuel cell.
The electricity that we get from power outlets and batteries can power all different kinds of devices. The fact is that electricity can be used in a thousand different ways. For example:
Electric motors turn electricity into motion.
Light bulbs, fluorescent lamps and LEDs turn electricity into light.
Computers turn electricity into information.
Telephones turn electricity into communication.
TVs turn electricity into moving pictures.
Speakers turn electricity into sound waves.
Stun guns turn electricity into pain.
Toasters, hair dryers and space heaters turn electricity into heat.
Radios turn electricity into electromagnetic waves that can travel millions of miles.
X-ray machines turn electricity into X-rays.
In many materials, the electrons are tightly bound to the atoms. Wood, glass, plastic, ceramic, air, cotton ... These are allThese are all examples of materials in which electrons stick with their atoms. Because the electrons don't move, these materials cannot conduct electricity very well, if at all. These materials are electrical insulators.
But most metals have electrons that can detach from their atoms and move around. These are called free electrons. Gold, silver, copper, aluminum, iron, etc., all have free electrons. The loose electrons make it easy for electricity to flow through these materials, so they are known as electrical conductors. They conduct electricity. The moving electrons transmit electrical energy from one point to another.
Voltage, Current and Resistance:
Imagine that you plug a space heater into a wall outlet. You measure the amount of current flowing from the wall outlet to the heater, and it is 10 amps. That means that it is a 1,200-watt heater.
Volts * Amps = Watts
... so 120 volts * 10 amps = 1,200 watts.
This is the same for any electrical appliance. If you plug in a toaster and it draws 5 amps, it is a 600-watt toaster. If you plug in a light and it draws half an amp, it is a 60-watt light bulb.
Let's say that you turn on the space heater, you go outside and you look at the power meter. The purpose of the power meter is to measure the amount of electricity flowing into your house so that the power company can bill you for it. Let's assume that nothing else in the house is on, so the meter is measuring only the electricity used by the space heater
Every utility pole on the planet has a bare wire like this. If you ever watch the power company install a new pole, you will see that the end of that bare wire is stapled in a coil to the base of the pole. That coil is in direct contact with the earth once the pole is installed, and is buried 6 to 10 feet (1.8 to 3 m) underground. It is a good, solid ground connection. If you examine a pole carefully, you will see that the ground wire running between poles (and often the guy wires) are attached to this direct connection to ground.
Similarly, near the power meter in your house or apartment there is a 6-foot (2-meter) long copper rod driven into the ground.
Electricity completely surrounds us -- For most of us, modern life would be impossible without it. Here are just a few examples:
Throughout your house, you probably find electrical outlets where you can plug in all sorts of electrical applicances.
Most portable devices contain batteries, which produce varying amounts of electricity depending on their size.
During a thunderstorm, there are huge bolts of electricity called lightning that shoot down from the sky.
On a much smaller scale, you can get a shock from static electricity on dry winter days.
The electricity that we get from power outlets and batteries can power all different kinds of devices. The fact is that electricity can be used in a thousand different ways. For example:
Electric motors turn electricity into motion.
Light bulbs, fluorescent lamps and LEDs turn electricity into light.
Computers turn electricity into information.
Telephones turn electricity into communication.
TVs turn electricity into moving pictures.
Speakers turn electricity into sound waves.
Stun guns turn electricity into pain.
Toasters, hair dryers and space heaters turn electricity into heat.
Radios turn electricity into electromagnetic waves that can travel millions of miles.
X-ray machines turn electricity into X-rays.
In many materials, the electrons are tightly bound to the atoms. Wood, glass, plastic, ceramic, air, cotton ... These are allThese are all examples of materials in which electrons stick with their atoms. Because the electrons don't move, these materials cannot conduct electricity very well, if at all. These materials are electrical insulators.
But most metals have electrons that can detach from their atoms and move around. These are called free electrons. Gold, silver, copper, aluminum, iron, etc., all have free electrons. The loose electrons make it easy for electricity to flow through these materials, so they are known as electrical conductors. They conduct electricity. The moving electrons transmit electrical energy from one point to another.
Voltage, Current and Resistance:
Imagine that you plug a space heater into a wall outlet. You measure the amount of current flowing from the wall outlet to the heater, and it is 10 amps. That means that it is a 1,200-watt heater.
Volts * Amps = Watts
... so 120 volts * 10 amps = 1,200 watts.
This is the same for any electrical appliance. If you plug in a toaster and it draws 5 amps, it is a 600-watt toaster. If you plug in a light and it draws half an amp, it is a 60-watt light bulb.
Let's say that you turn on the space heater, you go outside and you look at the power meter. The purpose of the power meter is to measure the amount of electricity flowing into your house so that the power company can bill you for it. Let's assume that nothing else in the house is on, so the meter is measuring only the electricity used by the space heater
Every utility pole on the planet has a bare wire like this. If you ever watch the power company install a new pole, you will see that the end of that bare wire is stapled in a coil to the base of the pole. That coil is in direct contact with the earth once the pole is installed, and is buried 6 to 10 feet (1.8 to 3 m) underground. It is a good, solid ground connection. If you examine a pole carefully, you will see that the ground wire running between poles (and often the guy wires) are attached to this direct connection to ground.
Similarly, near the power meter in your house or apartment there is a 6-foot (2-meter) long copper rod driven into the ground.
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