What is electricity?
Electricity is a form of energy. Electricity is the flow of electrons. All matter is made up of atoms, and an atom has a center, called a nucleus. The nucleus contains positively charged particles called protons and uncharged particles called neutrons. The nucleus of an atom is surrounded by negatively charged particles called electrons. The negative charge of an electron is equal to the positive charge of a proton, and the number of electrons in an atom is usually equal to the number of protons.
How is electricity produce?
An electric generator is a device for converting mechanical energy into electrical energy. The process is based on the relationship between magnetism and electricity. When a wire or any other electrically conductive material moves across a magnetic field, an electric current occurs in the wire. The large generators used by the electric utility industry have a stationary conductor. A magnet attached to the end of a rotating shaft is positioned inside a stationary conducting ring that is wrapped with a long, continuous piece of wire. When the magnet rotates, it induces a small electric current in each section of wire as it passes. This current is what is used for electric power.
How are electricity used?
Electricity are used in many thing including computer that we used, oven that we use to warm up food, light that help us to see better, hand phone that let us contact other ETC.
Showing posts with label electricity. Show all posts
Showing posts with label electricity. Show all posts
Friday, June 20, 2008
Electricity by 2E4 Chanchai Kovitpornsin
Name class 2E4 index no. 18
Electricity
I have learnt electricity is a form of energy. It is very convenient because it be changed to other forms of energy.
How electricity produced
I have learnt electricity energy comes from 2 main sources. There are electricity and electricity cells.
Main electricity is generated in power station. The plugs of electricity appliances are inserted into mains sockets to obtain this electricity. Main electricity supplies a lot of energy.
Electricity cells give out only a little energy. They are used in many portable electrical devices and safe to use.
Electric Circuits
I have learnt to make an electrical appliance work, electricity must flow through it. The flow of electricity is called an electric current. An electric current flow only when there is: 1. A source of electrical energy and 2. A closed circuit.
Electric Current
I have learnt an electric current is the flow of electrons in one direction in a circuit.
Measuring Electric Current
I have learnt to measure the electric current, we use an ammeter.
The SI unit for electric current is the ampere (A). Smaller currents can be measured in milliamperes (mA)
1 A = 1000 mA
1 mA= 1/1000 A (or 0.001 A)
Voltage
I have learnt voltage is a measure of how much energy the electrons receive. To measure voltage we use a voltmeter.
The SI for voltage is the volt (V).
Used of electricity
Electrical energy is changed to sound energy in radios.
Electrical energy is changed to heat energy in rice cookers.
Electrical energy is changed to kinetic energy in electric fans.
Key points
Electricity is a form of energy.
Electricity energy comes from 2 main sources. There are electricity and electricity cells.
The flow of electricity is called an electric current. An electric current flow only when there is: 1. A source of electrical energy and 2. A closed circuit.
An electric current is the flow of electrons in one direction in a circuit
Voltage is a measure of how much energy the electrons receive. To measure voltage we use a voltmeter.
History
That certain objects such as rods of amber could be rubbed with cat's fur and attract light objects like feathers was known to ancient cultures around the Mediterranean. Thales of Miletos conducted a series of experiments into static electricity around 600 BC, from which he believed that friction rendered amber magnetic, in contrast to minerals such as magnetite, which needed no rubbing. Thales was incorrect in believing the attraction was due to a magnetic effect, but later science would prove a link between magnetism and electricity.
Information
http://en.wikipedia.org/wiki/Electricity
Science Discovery 2 textbook
Electricity
I have learnt electricity is a form of energy. It is very convenient because it be changed to other forms of energy.
How electricity produced
I have learnt electricity energy comes from 2 main sources. There are electricity and electricity cells.
Main electricity is generated in power station. The plugs of electricity appliances are inserted into mains sockets to obtain this electricity. Main electricity supplies a lot of energy.
Electricity cells give out only a little energy. They are used in many portable electrical devices and safe to use.
Electric Circuits
I have learnt to make an electrical appliance work, electricity must flow through it. The flow of electricity is called an electric current. An electric current flow only when there is: 1. A source of electrical energy and 2. A closed circuit.
Electric Current
I have learnt an electric current is the flow of electrons in one direction in a circuit.
Measuring Electric Current
I have learnt to measure the electric current, we use an ammeter.
The SI unit for electric current is the ampere (A). Smaller currents can be measured in milliamperes (mA)
1 A = 1000 mA
1 mA= 1/1000 A (or 0.001 A)
Voltage
I have learnt voltage is a measure of how much energy the electrons receive. To measure voltage we use a voltmeter.
The SI for voltage is the volt (V).
Used of electricity
Electrical energy is changed to sound energy in radios.
Electrical energy is changed to heat energy in rice cookers.
Electrical energy is changed to kinetic energy in electric fans.
Key points
Electricity is a form of energy.
Electricity energy comes from 2 main sources. There are electricity and electricity cells.
The flow of electricity is called an electric current. An electric current flow only when there is: 1. A source of electrical energy and 2. A closed circuit.
An electric current is the flow of electrons in one direction in a circuit
Voltage is a measure of how much energy the electrons receive. To measure voltage we use a voltmeter.
History
That certain objects such as rods of amber could be rubbed with cat's fur and attract light objects like feathers was known to ancient cultures around the Mediterranean. Thales of Miletos conducted a series of experiments into static electricity around 600 BC, from which he believed that friction rendered amber magnetic, in contrast to minerals such as magnetite, which needed no rubbing. Thales was incorrect in believing the attraction was due to a magnetic effect, but later science would prove a link between magnetism and electricity.
Information
http://en.wikipedia.org/wiki/Electricity
Science Discovery 2 textbook
Electricity by 2E1 Chen Meng
What is electricity?
It is a controllable and convenient form of energy,
evident from the fact that it runs machinery and can
be transformed into other types of energy such as
light and heat.
It is invisible. During an electrical
storm, we do not see electricity.
We observe the air being ionized when
the electricity travels through it.
Sources of electricity
Electrical energy comes from two main sources. There are mains electricity and electric cells.
Main electricity is generated in power stations. The plugs of electrical appliances are inserted into mains sockets to obtain this electricity. Mains electricity supplies a lot of energy. It can give us an electric shock which can kill us. Never touch bare wires connected to mains electricity.
Electric cells give out only a little energy. They are used in many portable electrical devices and are safe to use.
Types of electricity
Static electricity is electricity that says still on objects.
Current electricity is electricity that flows in an electric circuit.
Electric circuits
To make an electrical appliance work, electricity must flow through it. The flow of electricity is called an electric current.
The path along which the electric current moves is called the electric circuit.
In the laboratory, experiments with electricity are often done on a circuit board.
On the circuit board, we join up electrical components to make a circuit.
Closed circuit & open circuits
For the bulb to light up, there has to be a complete path without any gap from one end of the cell to the light bulb and back to the other end of the cell. This complete path is called a closed circuit.
Each circuit has a gap in it and the bulbs do not light up. Incomplete circuits are called open circuits.
An electric current flow only when there is a source of electrical energy and a closed circuit.
Cell
Supplies electrical energy.The larger terminal (on the left) is positive (+). A single cell is often called a battery, but strictly a battery is two or more cells joined together.
Battery
Supplies electrical energy. A battery is more than one cell.The larger terminal (on the left) is positive (+).
Output Devices: Lamps, Heater, Motor, etc.
Component
Circuit Symbol
Function of Component
Lamp (lighting)
A transducer which converts electrical energy to light. This symbol is used for a lamp providing illumination, for example a car headlamp or torch bulb.
Lamp (indicator)
A transducer which converts electrical energy to light. This symbol is used for a lamp which is an indicator.
Heater
A transducer which converts electrical energy to heat.
Motor
A transducer which converts electrical energy to kinetic energy (motion).
Bell
A transducer which converts electrical energy to sound.
Buzzer
A transducer which converts electrical energy to sound.
Push Switch(push-to-make)
A push switch allows current to flow only when the button is pressed. This is the switch used to operate a doorbell.
Push-to-Break Switch
This type of push switch is normally closed (on), it is open (off) only when the button is pressed.
On-Off Switch(SPST)
SPST = Single Pole, Single Throw.An on-off switch allows current to flow only when it is in the closed (on) position.
Resistor
A resistor restricts the flow of current, for example to limit the current passing through an LED. A resistor is used with a capacitor in a timing circuit. Some publications still use the old resistor symbol:
Variable Resistor(Rheostat)
This type of variable resistor with 2 contacts (a rheostat) is usually used to control current. Examples include: adjusting lamp brightness, adjusting motor speed, and adjusting the rate of flow of charge into a capacitor in a timing circuit.
Voltmeter
A voltmeter is used to measure voltage. The proper name for voltage is 'potential difference', but most people prefer to say voltage!
Ammeter
An ammeter is used to measure current.
Ohmmeter
An ohmmeter is used to measure resistance. Most multimeters have an ohmmeter setting.
Switches
A switch is used to open or close a circuit.
Conductors & Insulators
Allows electricity to pass through it is called an electrical conductor.
A material which does not allow electricity to pass through it is called an electrical insulator.
What is voltage?
Voltage is a measure of how much energy the electrons receive. To measure voltage we use a voltmeter.
The SI unit for voltage is the volt (V).
Series circuits & parallel circuits
Electric circuits can be classified into two main types----series circuits and parallel circuits.
In a series circuits, each component is joined to the next to form a single path. The current that flows through each of the components is the same. However, a break in any part of a series circuit stops the flow of current in the whole circuit.
☆ the current at different points of the electric circuit is the same.
☆ the voltage of the energy source is the sum of the voltage of all the batteries in series.
☆ the total voltage across the whole circuit is the sum of the voltage of all the batteries in series.
A parallel circuit divides into two or more branches with electrical components in each branch. The current divides and flows through each of the three branches. An advantage of this circuit is that if one bulb breaks or is removed, the other bulbs remain lit.
☆ the current is the sum of all the current in the braches of a parallel circuit.
☆ the voltage across each branch is the same.
☆ the total voltage of cells/batteries connected on parallel is the voltage of one cell/battery.
What is an Electric Current?
An electric current is the flow of electrons in one direction in a circuit.
How does electricity travel in circuits?
Electricity travels in closed circuits. It must have a complete path before the electrons can move. If a circuit is open, the electrons cannot flow. When we flip on a light switch, we close a circuit. The electricity flows from the electric wire through the light and back into the wire. When we flip the switch off, we open the circuit. No electricity flows to the light. Electricity flows through a tiny wire in the bulb when we turn a light switch on. The wire gets very hot. It makes the gas in the bulb glow. When the bulb burns out, the tiny wire has broken. The path through the bulb is gone.
Measuring electric current
An ammeter is used to measure the electric current.
The SI unit for electric current is the ampere (A). Smaller currents can be measured in milliamperes (mA)
1A=1000mA
1mA=1/1000A
What is resistor?
An electricity component that is specially made to have a certain resistance is called a resistor.
Resistors that have one fixed resistance are called fixed resistors.
We used rheostat to change the current in a circuit. (rheostat which is also called a variable resistor.)
Resistance = voltage across component /
Current though component
Effects of an electric current
The flow of an electric current produces three effects.
☆ HEATING effect
☆ CHEMICAL effect
☆ MAGNETIC effect
The above sources are taken from website and sec. 2 textbook.
http://www.eia.doe.gov/kids/energyfacts/sources/electricity.html
http://www.sciencetech.technomuses.ca/english/schoolzone/Info_Electricity.cfm#whatis
http://people.virginia.edu/~bwk7j/basic.htm
http://www.kpsec.freeuk.com/symbol.htm
It is a controllable and convenient form of energy,
evident from the fact that it runs machinery and can
be transformed into other types of energy such as
light and heat.
It is invisible. During an electrical
storm, we do not see electricity.
We observe the air being ionized when
the electricity travels through it.
Sources of electricity
Electrical energy comes from two main sources. There are mains electricity and electric cells.
Main electricity is generated in power stations. The plugs of electrical appliances are inserted into mains sockets to obtain this electricity. Mains electricity supplies a lot of energy. It can give us an electric shock which can kill us. Never touch bare wires connected to mains electricity.
Electric cells give out only a little energy. They are used in many portable electrical devices and are safe to use.
Types of electricity
Static electricity is electricity that says still on objects.
Current electricity is electricity that flows in an electric circuit.
Electric circuits
To make an electrical appliance work, electricity must flow through it. The flow of electricity is called an electric current.
The path along which the electric current moves is called the electric circuit.
In the laboratory, experiments with electricity are often done on a circuit board.
On the circuit board, we join up electrical components to make a circuit.
Closed circuit & open circuits
For the bulb to light up, there has to be a complete path without any gap from one end of the cell to the light bulb and back to the other end of the cell. This complete path is called a closed circuit.
Each circuit has a gap in it and the bulbs do not light up. Incomplete circuits are called open circuits.
An electric current flow only when there is a source of electrical energy and a closed circuit.
Cell
Supplies electrical energy.The larger terminal (on the left) is positive (+). A single cell is often called a battery, but strictly a battery is two or more cells joined together.
Battery
Supplies electrical energy. A battery is more than one cell.The larger terminal (on the left) is positive (+).
Output Devices: Lamps, Heater, Motor, etc.
Component
Circuit Symbol
Function of Component
Lamp (lighting)
A transducer which converts electrical energy to light. This symbol is used for a lamp providing illumination, for example a car headlamp or torch bulb.
Lamp (indicator)
A transducer which converts electrical energy to light. This symbol is used for a lamp which is an indicator.
Heater
A transducer which converts electrical energy to heat.
Motor
A transducer which converts electrical energy to kinetic energy (motion).
Bell
A transducer which converts electrical energy to sound.
Buzzer
A transducer which converts electrical energy to sound.
Push Switch(push-to-make)
A push switch allows current to flow only when the button is pressed. This is the switch used to operate a doorbell.
Push-to-Break Switch
This type of push switch is normally closed (on), it is open (off) only when the button is pressed.
On-Off Switch(SPST)
SPST = Single Pole, Single Throw.An on-off switch allows current to flow only when it is in the closed (on) position.
Resistor
A resistor restricts the flow of current, for example to limit the current passing through an LED. A resistor is used with a capacitor in a timing circuit. Some publications still use the old resistor symbol:
Variable Resistor(Rheostat)
This type of variable resistor with 2 contacts (a rheostat) is usually used to control current. Examples include: adjusting lamp brightness, adjusting motor speed, and adjusting the rate of flow of charge into a capacitor in a timing circuit.
Voltmeter
A voltmeter is used to measure voltage. The proper name for voltage is 'potential difference', but most people prefer to say voltage!
Ammeter
An ammeter is used to measure current.
Ohmmeter
An ohmmeter is used to measure resistance. Most multimeters have an ohmmeter setting.
Switches
A switch is used to open or close a circuit.
Conductors & Insulators
Allows electricity to pass through it is called an electrical conductor.
A material which does not allow electricity to pass through it is called an electrical insulator.
What is voltage?
Voltage is a measure of how much energy the electrons receive. To measure voltage we use a voltmeter.
The SI unit for voltage is the volt (V).
Series circuits & parallel circuits
Electric circuits can be classified into two main types----series circuits and parallel circuits.
In a series circuits, each component is joined to the next to form a single path. The current that flows through each of the components is the same. However, a break in any part of a series circuit stops the flow of current in the whole circuit.
☆ the current at different points of the electric circuit is the same.
☆ the voltage of the energy source is the sum of the voltage of all the batteries in series.
☆ the total voltage across the whole circuit is the sum of the voltage of all the batteries in series.
A parallel circuit divides into two or more branches with electrical components in each branch. The current divides and flows through each of the three branches. An advantage of this circuit is that if one bulb breaks or is removed, the other bulbs remain lit.
☆ the current is the sum of all the current in the braches of a parallel circuit.
☆ the voltage across each branch is the same.
☆ the total voltage of cells/batteries connected on parallel is the voltage of one cell/battery.
What is an Electric Current?
An electric current is the flow of electrons in one direction in a circuit.
How does electricity travel in circuits?
Electricity travels in closed circuits. It must have a complete path before the electrons can move. If a circuit is open, the electrons cannot flow. When we flip on a light switch, we close a circuit. The electricity flows from the electric wire through the light and back into the wire. When we flip the switch off, we open the circuit. No electricity flows to the light. Electricity flows through a tiny wire in the bulb when we turn a light switch on. The wire gets very hot. It makes the gas in the bulb glow. When the bulb burns out, the tiny wire has broken. The path through the bulb is gone.
Measuring electric current
An ammeter is used to measure the electric current.
The SI unit for electric current is the ampere (A). Smaller currents can be measured in milliamperes (mA)
1A=1000mA
1mA=1/1000A
What is resistor?
An electricity component that is specially made to have a certain resistance is called a resistor.
Resistors that have one fixed resistance are called fixed resistors.
We used rheostat to change the current in a circuit. (rheostat which is also called a variable resistor.)
Resistance = voltage across component /
Current though component
Effects of an electric current
The flow of an electric current produces three effects.
☆ HEATING effect
☆ CHEMICAL effect
☆ MAGNETIC effect
The above sources are taken from website and sec. 2 textbook.
http://www.eia.doe.gov/kids/energyfacts/sources/electricity.html
http://www.sciencetech.technomuses.ca/english/schoolzone/Info_Electricity.cfm#whatis
http://people.virginia.edu/~bwk7j/basic.htm
http://www.kpsec.freeuk.com/symbol.htm
Electricity by 2E3 Joevenn Ng
What Is Electricity?
Electricity is the flow of electrical power or charge. It is a secondary energy source which means that we get it from the conversion of other sources of energy, like coal, natural gas, oil, nuclear power and other natural sources, which are called primary sources. The energy sources we use to make electricity can be renewable or non-renewable, but electricity itself is neither renewable or non-renewable.
Source for this question: http://www.eia.doe.gov/kids/energyfacts/sources/electricity.html
How Is Electricity Produced?
Electricity generation - whether from fossil fuels, nuclear, renewable fuels, or other sources - is usually* based on the fact that "When magnets are moved near a wire, an electric current is generated in that wire."
"When magnets are moved near a wire, an electric current is generated in that wire."
Source for this question: http://hawaii.gov/dbedt/info/energy/renewable/electricitygeneration/
Uses Of Electricity.
Well electricity is widely used all around the world. They are used to do things like using a computer , charging of handphones and others. Electricity is used or all used for good and bad things.
Electricity is the flow of electrical power or charge. It is a secondary energy source which means that we get it from the conversion of other sources of energy, like coal, natural gas, oil, nuclear power and other natural sources, which are called primary sources. The energy sources we use to make electricity can be renewable or non-renewable, but electricity itself is neither renewable or non-renewable.
Source for this question: http://www.eia.doe.gov/kids/energyfacts/sources/electricity.html
How Is Electricity Produced?
Electricity generation - whether from fossil fuels, nuclear, renewable fuels, or other sources - is usually* based on the fact that "When magnets are moved near a wire, an electric current is generated in that wire."
"When magnets are moved near a wire, an electric current is generated in that wire."
Source for this question: http://hawaii.gov/dbedt/info/energy/renewable/electricitygeneration/
Uses Of Electricity.
Well electricity is widely used all around the world. They are used to do things like using a computer , charging of handphones and others. Electricity is used or all used for good and bad things.
Electricity by 2E2 Amruth
What is electricity?
*Electricity is a form of energy and it is convenient as it can be changed into other forms of energy.
What are the effects of electricity on our daily lives?
*We are able to; play games on our computer, travel in cars and other transportations, Watch television, use handphones, etc.
What is the electric current?
*It is the flow of electricity.
What is the electrical circuit?
*It is the path where current moves.
What is the meaning of closed circuit and open circuits?
Closed circuit
*It is a complete path of electricity from one end to the other.
Open circuit
*It is an incomplete path of electricity from one end.
Why are switches used in our daily life?
It is safer way to conduct electricity and to open and close circuits.
What is voltage?
*Voltage is the energy per unit charge.
What is the SI unit for voltage?
*The SI unit for voltage is volt ( V ).
Some interesting stuff…….
*In the times when humans first appeared on Earth, the created electricity by rubbing two materials together.
*The first machine to make an electrical spark was created at 1650; it worked by rubbing a hand on a spinning sulphur ball…. Electricity through friction?
RESOURCES
http://www.historyoftheuniverse.com/electric.html
http://en.wikipedia.org/wiki/Voltage
Book: Explore your world with SCIENCE DISCOVERY 2
Publisher: Pearson Longman
Author : Rex M Heyworth
*Electricity is a form of energy and it is convenient as it can be changed into other forms of energy.
What are the effects of electricity on our daily lives?
*We are able to; play games on our computer, travel in cars and other transportations, Watch television, use handphones, etc.
What is the electric current?
*It is the flow of electricity.
What is the electrical circuit?
*It is the path where current moves.
What is the meaning of closed circuit and open circuits?
Closed circuit
*It is a complete path of electricity from one end to the other.
Open circuit
*It is an incomplete path of electricity from one end.
Why are switches used in our daily life?
It is safer way to conduct electricity and to open and close circuits.
What is voltage?
*Voltage is the energy per unit charge.
What is the SI unit for voltage?
*The SI unit for voltage is volt ( V ).
Some interesting stuff…….
*In the times when humans first appeared on Earth, the created electricity by rubbing two materials together.
*The first machine to make an electrical spark was created at 1650; it worked by rubbing a hand on a spinning sulphur ball…. Electricity through friction?
RESOURCES
http://www.historyoftheuniverse.com/electric.html
http://en.wikipedia.org/wiki/Voltage
Book: Explore your world with SCIENCE DISCOVERY 2
Publisher: Pearson Longman
Author : Rex M Heyworth
Electricity by 2E2 Naqiah
Electricity
Electricity is a form of energy produced by the movement of electrons. Electricity is electrical power or an electric current. This form of energy can be sent through wires in a flow of tiny particles. It is used to produce light and heat and to run motors.
Electricity is a basic feature of all matter, of everything in the universe. Electrical force holds atoms and molecules together. Electricity determines the structure of every object that exists. Together with magnetism, it causes a force called electromagnetism, a fundamental force of the universe. Electricity or electrical signals are essential to many biological processes. In our bodies, electrical signals are carried through the nervous system, moving information to and from the brain. Electrical signals communicate to our brain what the eyes see, what the ears hear, and what the fingers feel.
Electrical signals from our brain causes our muscle movements. Electrical signals cause each heartbeat. One of the most important forms of electricity is in electrical current. During the industrial revolution of the 1800s, people began to find ways to use electricity to do work. Today electricity is used throughout our homes, at work, in communication, in transportation, and in medicine and science.
Electrically powered devices are prevalent. Relatively cheap electricity has made electrical appliances, machines, and other devices possible. A major reason electricity works is because of conductors. First metal, water, tall trees and tall items are good conductors because lightning is attracted to them. These materials have many mobile electrons.
Metal is an easy substance for lightning to travel through so metals are good conductors.However, rubber is a bad conductor because lightning bounces off of it. A bad conductor is called an insulator. An insulator has a few mobile electrons. It is important for us to know the difference between good conductors and insulators because if you're outside in an open field during a storm you will know where to go to be safe from the lightning. Truly, knowing the difference between conductors and insulators of electricity can save our lives.
It is a secondary energy source which means that we get it from the conversion of other sources of energy, like coal, natural gas, oil, nuclear power and other natural sources, which are called primary sources. The energy sources we use to make electricity can be renewable or non-renewable, but electricity itself is neither renewable or non-renewable.
(http://library.thinkquest.org/J001647F/)(http://42explore.com/electric.htm)
Electricity is a form of energy produced by the movement of electrons. Electricity is electrical power or an electric current. This form of energy can be sent through wires in a flow of tiny particles. It is used to produce light and heat and to run motors.
Electricity is a basic feature of all matter, of everything in the universe. Electrical force holds atoms and molecules together. Electricity determines the structure of every object that exists. Together with magnetism, it causes a force called electromagnetism, a fundamental force of the universe. Electricity or electrical signals are essential to many biological processes. In our bodies, electrical signals are carried through the nervous system, moving information to and from the brain. Electrical signals communicate to our brain what the eyes see, what the ears hear, and what the fingers feel.
Electrical signals from our brain causes our muscle movements. Electrical signals cause each heartbeat. One of the most important forms of electricity is in electrical current. During the industrial revolution of the 1800s, people began to find ways to use electricity to do work. Today electricity is used throughout our homes, at work, in communication, in transportation, and in medicine and science.
Electrically powered devices are prevalent. Relatively cheap electricity has made electrical appliances, machines, and other devices possible. A major reason electricity works is because of conductors. First metal, water, tall trees and tall items are good conductors because lightning is attracted to them. These materials have many mobile electrons.
Metal is an easy substance for lightning to travel through so metals are good conductors.However, rubber is a bad conductor because lightning bounces off of it. A bad conductor is called an insulator. An insulator has a few mobile electrons. It is important for us to know the difference between good conductors and insulators because if you're outside in an open field during a storm you will know where to go to be safe from the lightning. Truly, knowing the difference between conductors and insulators of electricity can save our lives.
It is a secondary energy source which means that we get it from the conversion of other sources of energy, like coal, natural gas, oil, nuclear power and other natural sources, which are called primary sources. The energy sources we use to make electricity can be renewable or non-renewable, but electricity itself is neither renewable or non-renewable.
(http://library.thinkquest.org/J001647F/)(http://42explore.com/electric.htm)
Electricity by 2E2 Siti Azwani
Electricity
i) I have learnt that electricity is a controllable and convenient form of energy used in everyday life. Electricity is the flow of electrons. Without it, we may not be able to perform our everyday routine. Mainly, we used electricity for work, play, in the house and at work, (and at school).
ii) Electricity is a basic part of nature and it is one of our most widely used forms of energy. We get electricity, which is a secondary energy source, from the conversion of other sources of energy, like coal, natural gas, oil, nuclear power and other natural sources, which are called primary sources.
In every electricity, there will always be an electric current. An electric current is a flow of electric charge around a circuit. The charge is already in the wires. This charge is evenly spread out through the wires. As soon as you close the switch, the cell starts to push on the charge. So all the charge starts moving at once. An electric cell gives energy to the electrons and pushes them around a circuit.
Voltage is a measure of how much energy the electrons receive.
iv) acknowledge from: sec 2 Science textbook and wikipedia.com
i) I have learnt that electricity is a controllable and convenient form of energy used in everyday life. Electricity is the flow of electrons. Without it, we may not be able to perform our everyday routine. Mainly, we used electricity for work, play, in the house and at work, (and at school).
ii) Electricity is a basic part of nature and it is one of our most widely used forms of energy. We get electricity, which is a secondary energy source, from the conversion of other sources of energy, like coal, natural gas, oil, nuclear power and other natural sources, which are called primary sources.
In every electricity, there will always be an electric current. An electric current is a flow of electric charge around a circuit. The charge is already in the wires. This charge is evenly spread out through the wires. As soon as you close the switch, the cell starts to push on the charge. So all the charge starts moving at once. An electric cell gives energy to the electrons and pushes them around a circuit.
Voltage is a measure of how much energy the electrons receive.
iv) acknowledge from: sec 2 Science textbook and wikipedia.com
Electricity by 2E3 Serene Pang
What is electricity?
Electricity is a naturally occurring force that exists all around us.
How is electricity being produced?
Electricity energy comes from 2 main sources. These are mains electricity and electricity cells.
Main electricity is generated in power stations. The plugs of electrical appliances are inserted into main sockets to obtain this electricity.
Electric cells give out only a little energy. They are called batteries.
What is current?
An electric current is the flow of electrons in one direction in a circuit. We use an ammeter to the size of the electric current. The SI unit for electric current is the ampere (A). The picture shows a ammeter.
What is voltage?
Voltage is a measure of how much energy the electrons receive. To measure voltage, we use voltmeter. The SI unit for voltage is the volt (V). The picture shows a voltmeter.
Uses of electricity
Electricity is the most widely used type of energy in the world. We use it for work and for play, in the home and at work. In the past it mainly provided us with light and heat. Nowadays, the number of electronic appliances has hugely increased, we now use it almost everyday. We also use it for daily applications such as light, fan, etc. It also improves our lives.
Source obtained from textbooks, http://www.teachnet.ie/pcoakley/consumers.htm,
Electricity is a naturally occurring force that exists all around us.
How is electricity being produced?
Electricity energy comes from 2 main sources. These are mains electricity and electricity cells.
Main electricity is generated in power stations. The plugs of electrical appliances are inserted into main sockets to obtain this electricity.
Electric cells give out only a little energy. They are called batteries.
What is current?
An electric current is the flow of electrons in one direction in a circuit. We use an ammeter to the size of the electric current. The SI unit for electric current is the ampere (A). The picture shows a ammeter.
What is voltage?
Voltage is a measure of how much energy the electrons receive. To measure voltage, we use voltmeter. The SI unit for voltage is the volt (V). The picture shows a voltmeter.
Uses of electricity
Electricity is the most widely used type of energy in the world. We use it for work and for play, in the home and at work. In the past it mainly provided us with light and heat. Nowadays, the number of electronic appliances has hugely increased, we now use it almost everyday. We also use it for daily applications such as light, fan, etc. It also improves our lives.
Source obtained from textbooks, http://www.teachnet.ie/pcoakley/consumers.htm,
Thursday, June 19, 2008
Electricity by 2E4 Nurhakim
What is the importance of using Electricity?
Electricity is a form of energy. Around us, we are almost surrounded by Electricity.
Examples, Computer & Hand phone. Without Electricity, modern life would be impossible. Imagine there is a Blackout; the life of an electric still goes on as it works on a battery.
Sources of Electricity
There are 2 main sources, main electricity and electric cells.
Main Electricity
Main Electricity is generated by in power plants or power station. There are another 2 types of main electricity.
Re-useable energy
Non-renewable Energy
Electric Cells
Electric Cells gives out very little energy. These are used in many portable electrical devices and are safe to use.
Most of the Electric uses are mainly for…
Communication [To make communication in Space and the Earth]
Electronics [Electronic gadgets]
Telephones [Another type of communication]
Faxes & Modem [Another type of communication]
Radio [Another type of communication]
Television [Another type of communication]
Computers [Another type of communication]
& many more
Electricity is a form of energy. Around us, we are almost surrounded by Electricity.
Examples, Computer & Hand phone. Without Electricity, modern life would be impossible. Imagine there is a Blackout; the life of an electric still goes on as it works on a battery.
Sources of Electricity
There are 2 main sources, main electricity and electric cells.
Main Electricity
Main Electricity is generated by in power plants or power station. There are another 2 types of main electricity.
Re-useable energy
Non-renewable Energy
Electric Cells
Electric Cells gives out very little energy. These are used in many portable electrical devices and are safe to use.
Most of the Electric uses are mainly for…
Communication [To make communication in Space and the Earth]
Electronics [Electronic gadgets]
Telephones [Another type of communication]
Faxes & Modem [Another type of communication]
Radio [Another type of communication]
Television [Another type of communication]
Computers [Another type of communication]
& many more
Electricity by 2E1 Xu Lingyin
Key point
- Electricity is a basic part of nature.
Electricity is a secondary energy source.
Electricity itself is neither renewable or non-renewable.
Applying a force can make them move from one atom to another. These moving electrons are electricity.
A battery produces electricity using two different metals in a chemical solution.
The end that frees more electrons develops a positive charge and the other end develops a negative charge.
A chemical reaction between the metals and the chemicals frees more electrons in one metal than in the other.
circuit, measured in Coulombs/second which is named Amperes.
The standard abbreviations for the units are 1 A = 1C/s
Voltage is electric potential energy per unit charge, measured in joules per coulomb ( = volts).
It is often referred to as "electric potential", which then must be distinguished from electric potential energy by noting that the "potential" is a "per-unit-charge" quantity.
The difference in voltage measured when moving from point A to point B is equal to the work which would have to be done, per unit charge, against the electric field to move the charge from A to B.
We use a lot of energy - in our homes, in businesses, in industry, and for traveling between all these different places.
What is electricity?
Electricity is a basic part of nature and it is one of our most widely used forms of energy. And it flow of electrical power or charge.
How is electricity being produced?
Electricity is a secondary energy source which means that we get it from the conversion of other sources of energy, like coal, natural gas, oil, nuclear power and other natural sources ,which are called primary sources.The energy sources we use to make electricity can be renewable or non-renewable, but electricity itself is neither renewable or non-renewable. Despite its great importance in our daily lives, most of us rarely stop to think what life would be like without electricity. Yet like air and water, we tend to take electricity for granted. Everyday, we use electricity to do many jobs for us -- from lighting and heating/cooling our homes, to powering our televisions and computers. Electricity is a controllable and convenient form of energy used in the applications of heat, light and power.
In order to understand how electricity charge moves from one atom to another, we need to know something about atoms. Everything in the universe is made of atoms—every star, every tree, every animal. The human body is made of atoms. Air and water are, too. Atoms are the building blocks of the universe. Atoms are so small that millions of them would fit on the head of a pin.
Atoms are made of even smaller particles. The center of an atom is called the nucleus. It is made of particles called protons and neutrons. The protons and neutrons are very small, but electrons are much, much smaller. Electrons spin around the nucleus in shells a great distance from the nucleus. If the nucleus were the size of a tennis ball, the atom would be the size of the Empire State Building. Atoms are mostly empty space.
If you could see an atom, it would look a little like a tiny center of balls surrounded by giant invisible bubbles (or shells). The electrons would be on the surface of the bubbles, constantly spinning and moving to stay as far away from each other as possible. Electrons are held in their shells by an electrical force.
The protons and electrons of an atom are attracted to each other. They both carry an electrical charge. An electrical charge is a force within the particle. Protons have a positive charge (+) and electrons have a negative charge (-). The positive charge of the protons is equal to the negative charge of the electrons. Opposite charges attract each other. When an atom is in balance, it has an equal number of protons and electrons. The neutrons carry no charge and their number can vary.
The number of protons in an atom determines the kind of atom, or element, it is. An element is a substance in which all of the atoms are identical . Every atom of hydrogen, for example, has one proton and one electron, with no neutrons. Every atom of carbon has six protons, six electrons, and six neutrons. The number of protons determines which element it is.
Electrons usually remain a constant distance from the nucleus in precise shells. The shell closest to the nucleus can hold two electrons. The next shell can hold up to eight. The outer shells cans hold even more. Some atoms with many protons can have as many as seven shells with electrons in them.
The electrons in the shells closest to the nucleus have a strong force of attraction to the protons. Sometimes, the electrons in the outermost shells do not. These electrons can be pushed out of their orbits. Applying a force can make them move from one atom to another. These moving electrons are electricity.
BATTERIES PRODUCE ELECTRICITY
A battery produces electricity using two different metals in a chemical solution. A chemical reaction between the metals and the chemicals frees more electrons in one metal than in the other. One end of the battery is attached to one of the metals; the other end is attached to the other metal. The end that frees more electrons develops a positive charge and the other end develops a negative charge. If a wire is attached from one end of the battery to the other, electrons flow through the wire to balance the electrical charge. A load is a device that does work or performs a job. If a load such as a lightbulb is placed along the wire, the electricity can do work as it flows through the wire. In the picture above, electrons flow from the negative end of the battery through the wire to the lightbulb.
The electricity flows through the wire in the lightbulb and back to the battery.
What is Electric Current?
Electric current is the rate of charge flow past a given point in an electric circuit, measured in Coulombs/second which is named Amperes. In most DC electric circuits, it can be assumed that the resistance to current flow is a constant so that the current in the circuit is related to voltage and resistance by Ohm's law. The standard abbreviations for the units are 1 A = 1C/s
.
What is Voltage ？
Voltage is electric potential energy per unit charge, measured in joules per coulomb ( = volts). It is often referred to as "electric potential", which then must be distinguished from electric potential energy by noting that the "potential" is a "per-unit-charge" quantity. Like mechanical potential energy, the zero of potentil can be chosen at any point, so the difference in voltage is the quantity which is physically meaningful. The difference in voltage measured when moving from point A to point B is equal to the work which would have to be done, per unit charge, against the electric field to move the charge from A to B.
Used to calculate current in Ohm's law
Used to express conservation of energy around a circuit in the voltage law
Used to calculate the potential from a distribution of charges
Is generated by moving a wire in a magnetic field
Uses of electricity?
Take a look at all the things we depend on each day that need electricity:
In the kitchen:
Refrigerators
Dishwashers
Stoves
In the family room:
Lamps
Computers
Air conditioning
In the basement or utility room:
Washer and dryer
Furnace
Water heater
Outdoors:
Outdoor lighting
Electric lawn mower
Pool heater
Example:
The United States is a highly developed and industrialized society. We use a lot of energy - in our homes, in businesses, in industry, and for traveling between all these different places.
The industrial sector uses about one-third of the total energy. The residential and commercial sectors combined use even more than this - 40 percent of all energy. These two sectors include all types of buildings, such as houses, offices, stores, restaurants, and places of worship. Energy used for transportation accounts for more than a quarter of all energy.
From this topic,I know Electricity is a form of energy produced by the movement of electrons. Electricity is electrical power or an electric current. This form of energy can be sent through wires in a flow of tiny particles. It is used to produce light and heat and to run motors. Electricity is a basic feature of all matter, of everything in the universe.
Websites
http://www.eia.doe.gov/kids/energyfacts/sources/electricity.html
http://images.google.cn/images?complete=1&hl=zh-CN&rlz=1T4SKPB_zh-CNSG272SG272&q=electricity%20&um=1&ie=UTF-8&sa=N&tab=wi
http://42explore.com/electric.htm
Electricity by 2E3 Bernard Kay
What is electricity
Electricity is a form of energy.It is very convenient because it can be changed to other forms of energy.Electrical energy is changed to sound energy in radios,to heat energy in rice cookers and to kinetic energy in radios,to heat energy in rice cookers and to kinetic energy in electric fans.
How is electricity produced
Electricity is produced generated in power stations.The plugs of the electrical appliances are inserted into mains sockets to obtain this electricity.Main electricity supplies a lot of energy.It can give us an electric shock which can kill us.
Electricity can also be produced from fossil fuels,hydro dams,static electricity.
Uses of electricity
Electricity is used to power up our daily usage such as.Computers,lamps,air conditioning,furnace,water heater
Electricity is a form of energy.It is very convenient because it can be changed to other forms of energy.Electrical energy is changed to sound energy in radios,to heat energy in rice cookers and to kinetic energy in radios,to heat energy in rice cookers and to kinetic energy in electric fans.
How is electricity produced
Electricity is produced generated in power stations.The plugs of the electrical appliances are inserted into mains sockets to obtain this electricity.Main electricity supplies a lot of energy.It can give us an electric shock which can kill us.
Electricity can also be produced from fossil fuels,hydro dams,static electricity.
Uses of electricity
Electricity is used to power up our daily usage such as.Computers,lamps,air conditioning,furnace,water heater
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