Electricity Merit Badge – Electricity is a big part of how Americans use energy today. You can do no work at all without energy. Think about how your life changes when power fails during bad weather.
You cannot flip on a light, watch television, use the computer, run a fan, toast bread, warm a drink in the microwave, or do anything else that requires electricity. Most of your regular activities abruptly stop.
Now think what would happen if the entire United States had to go without power. The life of the country as we know it today could not continue.
Electricity Merit Badge Requirements
- Demonstrate that you know how to respond to electrical emergencies by doing the following:
- Show how to render first aid to a person who is unconscious from electrical shock.
- Show how to treat an electrical burn.
- Explain what to do in an electrical storm.
- Explain what to do in the event of an electrical fire.
- Complete an electrical home safety inspection of your home, using the checklist found in this pamphlet or one approved by your counselor. Discuss what you find with your counselor.
- Make a simple electromagnet and use it to show magnetic attraction and repulsion.
- Explain the difference between direct current and alternating current.
- Make a simple drawing to show how a battery and an electric bell work.
- Explain why a fuse blows or a circuit breaker trips. Tell how to find a blown fuse or tripped circuit breaker in your home. Show how to safely reset the circuit breaker.
- Explain what overloading an electric circuit means. Tell what you have done to make sure your home circuits are not overloaded.
- Make a floor plan wiring diagram of the lights, switches, and outlets for a room in your home. Show which fuse or circuit breaker protects each one.
- Do the following:
- Read an electric meter and, using your family’s electric bill, determine the energy cost from the meter readings.
- Discuss with your counselor five ways in which your family can conserve energy.
- Explain the following electrical terms: volt, ampere, watt, ohm, resistance, potential difference, rectifier, rheostat, conductor, ground, circuit, and short circuit.
- Do any TWO of the following:
- Connect a buzzer, bell, or light with a battery. Have a key or switch in the line.
- Make and run a simple electric motor (not from a kit).
- Build a single-pole, double-throw switch. Show that it works.
- Hook a model electric train layout to a house circuit. Tell how it works.
What is Electricity?
Electricity is a powerful and fascinating force of nature. As early as 600 b.c., observers of the physical world suspected that electricity existed but did not have a name for it. In fact, real progress in unraveling the mystery of electricity has come only within the last 250 years.
Important discoveries by scientists such as Benjamin Franklin, who proved that lightning is a tremendously powerful electrical spark, have given us a more complete picture of what electricity is and how we can harness its power.
To begin to understand electricity as an awesome force, one must start with the basics. Electricity is a rapid transfer of charged particles called electrons, which create levels of energy depending upon how they transfer.
All things are made of tiny particles called atoms. You are made of atoms, and so are your friends, your clothes, the food you eat, and the air you breathe.
Atoms are so small that it takes millions of them to form the period at the end of this sentence. Every atom is made up of even tinier particles called protons, neutrons, and electrons.
Protons are positively charged, and neutrons are neutral they have no charge. Together, protons and neutrons form the nucleus, or core, of an atom.
Electrons, which are negatively charged, speed around the nucleus, orbiting it in layers called shells. The positive charge of the protons in the nucleus equals the total negative charge of the electrons in orbit.
This makes the atom neutral or balanced. Protons and electrons have a natural attraction to each other, which helps to keep the atom stable.
Much as the gravitational force of the sun holds planets in their orbits, electrical forces hold electrons around the nucleus.
It is important to understand the atom’s structure because the electrical charge of the electron is the basic unit of electricity.
The position and movement of positively and negatively charged particles cause the electric and magnetic effects you will be working on to earn your Electricity merit badge.
2. Ions and Balance
The bond that holds electrons in orbit is weakest in the atom’s outermost shells. A free-moving electron can bump into and knock electrons out of an atom’s outermost shell.
These loose electrons, in turn, can bump into still other atoms and dislodge more electrons. Moving together, these freed electrons form electric current.
Electrons are easily dislodged from or rubbed off of, an atom because they are lightweight and, in the outermost shells, accessible. (Protons are heavy and do not rub off easily.)
Imagine electrons as grains of dust spinning swiftly around a central core of iron. You can see why the lightweight, negatively charged electrons are constantly rubbing off or being lifted by nearby atoms and ions.
The following information is to answer the requirements of 10 electricity merit badge.
Common Electrical Terms
To work with electricity, you need to know some common terms for using and measuring it. Several important terms are defined below.
|Alternating Current. The current that regularly reverses direction, traveling first in one direction and then in the opposite direction. Power companies generate alternating currents to make it easier to transmit electricity over long distances. Abbreviated AC.|
|Ammeter. An instrument for measuring current in amperes.|
|Ampere. A unit measuring the strength of an electrical current, based on the number of electrons transferring past a given point per second. Many elements of a wiring system are rated in amperes for the greatest amount of current they can safely carry. The ampere, abbreviated amp, is named for French physicist André-Marie Ampère.|
|Circuit. A loop-shaped path through which electric current travels from the source through some device using electricity, such as a lightbulb, and back to the source.|
|Circuit Breaker. A safety switch installed in a circuit to break the transfer of electricity when the current exceeds a set amount. Circuit breakers can be reset once “tripped.” See also fuse.|
|Conductor. A substance or device through which electricity passes. Most metals are good conductors of electricity that is, they allow electricity to travel through them with little resistance.|
Gold and silver are the best conductors of electricity but are too expensive for general use. Copper, which is relatively cheap and plentiful, is used most often, especially in transmission lines that carry electricity from power plants to homes, schools, and businesses. Devices that run on electricity have copper wiring. Aluminum is not as good a conductor as copper, but because it is cheaper and lighter, it is also frequently used.
|Cycle. One complete reversal of alternating current; a forward current and backward current. Ordinary household current experiences 60 cycles per second (60 hertz).|
|Current. The transfer of electricity in one direction.|
|Direct Current. An electric current of constant direction that is, the transfer of electrons goes only in one direction. Abbreviated DC.|
|Fuse. A safety device installed in a circuit to prevent an overload. Designed to melt or “blow” when current exceeds a set amount, it opens the circuit and stops the transfer of electricity. Fuses cannot be reused once blown. See also circuit breaker.|
|Ground. To connect any part of an electrical wiring system to the ground or to another conducting body, such as a metal water pipe or a metal rod is driven into the earth.|
|Galvanometer. A device that detects and determines the strength of electrical currents.|
|Grounding Wire. The conductor that grounds a metal component but does not carry current during normal operation.|
|Hertz. A unit of frequency equal to one cycle per second. Abbreviated Hz.|
|Hot Wire. Ungrounded conductor carrying electrical current. Usually identified by black or red insulation.|
|Insulation. Covering of nonconducting material used on wires.|
|Insulator. A material that does not conduct electricity, such as rubber or plastic.|
|Kilowatt. Unit of electrical power equal to 1,000 watts. Abbreviated kw.|
|Kilowatt-Hour. Unit of energy used for metering and selling electricity. One kilowatt-hour equals 1,000 watts used for one hour (or any equivalent, such as 500 watts used for two hours). Abbreviated kwh.|
|Load. The part of an electrical circuit that uses electric power. In a lighting circuit, the load is the lightbulb.|
|Neutral Wire. The grounded conductor that completes a circuit by providing a return path to the source. Always identified by white or gray insulation.|
|Ohm. A unit of measurement for electrical resistance to current. It is named for German physicist Georg Simon Ohm (1787-1854), whose Ohm’s law states that the pressure of one volt will cause a current of one ampere to flow through a resistance of one ohm (Voltage = Current X Resistance). This simple formula shows the relationship between volts, amperes, and resistance in an electric circuit.|
|Outlet. An electrical device where the switch can easily be connected to a fixture or equipment that uses electricity.|
|Overload. Condition in which an electrical circuit carries more current than it can safely handle.|
|Resistance. The opposition against the free transfer of electrons in a conductor. Measured in ohms.|
|Resistor. A device designed to restrict the transfer of current in (or introduce resistance into) an electric circuit.|
|Receptacle. The device that you plug electric cords into sometimes called an outlet.|
|Rheostat. A resistor built so that the current traveling through the circuit can be adjusted at will. Volume controls and dimmer switches are examples.|
|Short Circuit. A completed, low-resistance circuit that allows electrons to follow a shorter, unintended path back to the power source rather than follow the longer path that goes through the load. This occurs when bare wires touch each other; often result from worn insulation.|
|Source. Point of supply, such as a generator or battery.|
|Switch. Device to break the transfer of electricity. When the switch is on, the circuit is closed and current may travel through it. When the switch is off, the circuit is open and electricity cannot transfer.|
|Volt. A unit of potential difference, or a unit of measurement of electrical pressure or force. Abbreviated V.|
|Voltmeter. An instrument for measuring the difference in electric potential (electrical pressure) between two points.|
|Voltage. The pressure at which a circuit operates expressed in volts. Voltage is like the pressure in a water pipe. For example, 120 volts have twice the pushing force of 60 volts.|
|Watt. A unit that measures electrical power at the point where it is used in a circuit. One watt of power equals one volt of pressure times one ampere of current. Many electrical devices are rated in watts according to the power they consume. Abbreviated W.|
Here is some information to answer the requirements of 1 electricity merit badge badge.
Responding to Electrical Emergencies
Electrical outlets and wires pose the greatest danger to young children. Preschoolers love to insert hairpins, paper clips, and any number of other conductive objects into electrical sockets.
Toddlers often explore electrical outlets and wires by mouthing them. Since water is an excellent conductor of electricity, there is a danger of severe facial burns.
When not in use, electrical outlets should have protective guards plugged into them or be hidden and hard to reach behind furniture.
1. Electrical Shock
Electric shock is caused by electric current passing through a human body. The victim’s breathing may stop and his body may appear stiff. The electric contact must be broken as
quickly as possible.
If someone is in contact with a live circuit, do not touch the person. You can become “stuck” to him and part of the electrical field. If the service panel is nearby, quickly shut off the house current by throwing the main disconnect switch.
If it is a long way to the service panel, or you do not know where the main disconnect switch is, use a nonconducting object such as a wooden chair, wooden broom handle, rug, or rubber doormat to separate the person from the live wire.
Never use a metal or wet object.
If you can’t separate the victim from the wire using something like a broom handle, make sure you are standing on a perfectly dry surface and use a dry towel, sheet, sweater, or other heavy cloth to encircle the wire where it is not wet or bare.
Pull the wire from the victim. Never directly touch the wire or the victim. Don’t touch grounded objects like pipes under a sink.
If you can’t remove the wire, your final alternative is to use a cloth to pull the victim from the wire. Without touching the person, carefully loop a sweater or other piece of clothing around the victim, and grasping the ends of the clothing, pull the person away.
You might have to pull some distance before breaking contact with the wire. Do not touch the victim directly until the victim and the wire are separated.
If the person is not breathing after the rescue, start artificial respiration immediately. Call 911 for medical assistance.
2. Electrical Burn
Unless there is immediate danger, do not move a victim of electrical injury. Do not apply ice, butter, ointments, medication, bandages, or cotton dressings to electrical burns.
Do not touch burns, break blisters, or remove burned clothing. Electric shock causes burns inside the body, so immediately seek medical attention for the victim.
Once you and the victim are securely away from the electrical source, check the person’s wrist and the jugular vein in the neck for a pulse. If the victim is not breathing, start artificial respiration right away.
3. Electrical Fire
Electrical fires are different from other fires. Because water conducts electricity, you should never throw water on an electrical fire.
Here is what Southern California Edison suggests you do in the event of an electrical fire.
- Never use water on an electrical fire.
- Turn off the main power to the house.
- If the fire cannot be safely put out, leave the house
- immediately and take everyone with you.
- Call 911 from the nearest phone once you and your
- family are safely away from your home.
4. Electrical Strom
The draw of an open wilderness is powerful, but so are lightning strikes that are possible during an electrical storm.
If caught in the outdoors when a storm approaches, move away from open water, mountaintops, the crests of ridges, and the bases of tall or solitary trees.
A dense forest located in a depression offers the most protection. Avoid bodies of water and metal fences, too, and anything else that might conduct electricity. In a tent, stay away from metal tent poles.
if an electrical storm catches your group in the open, spread out so people are at least 100 feet from one another.
Further, minimize your risk by crouching low with only the soles of your shoes touching the ground. You can use your sleeping pad for insulation by folding it and crouching upon it.
Electrical Safety Inspection
For requirement 2 of the electricity merit badge, you will need to complete an electrical safety inspection of your home. Here are some items you can check in your home today to ensure electrical safety.
These tips come from the Electrical Safety Foundation International and can be found online at esfi.org.
Make an electrical safety checklist and walk through each room of your house, checking on each aspect of electrical safety.
You can go over your list with your counselor later and discuss what you found.
To complete the requirement 4 Electric Merit Badge, you can read the information below.
Alternating and Direct current
There are two kinds of electric current direct current (DC) and alternating current (AC). Direct current is like a one-way street the electrons go in only one direction. Turn on a flashlight and direct current travels. Car batteries also produce direct current.
In alternating current, the transfer of electrons starts from zero and builds to a peak in the positive direction, then subsides back down to zero. Then the transfer of electrons reverses, building to a negative peak and subsiding back to zero.
In this way, electrons alternately travel in positive and negative directions, continuously repeating until the circuit is opened. Large generators in power plants commonly produce alternating current for use in homes and factories.
Most household and industrial power circuits in the United States have alternating currents with a frequency of 60 cycles per second, or 60 hertz (Hz). This means that the current alternates back and forth, making a round-trip, or cycle, 60 times per second.
To make 60 round-trips, the current changes direction 120 times. Power systems in some other countries operate on a frequency other than 60 Hz.
Some appliances depend on the frequency of the alternating current and will not work properly in countries with different frequency electricity.
1. Using Alternating Current
Power companies prefer alternating current because it is readily produced by large generators, and it is easy to step its voltage up or down.
By passing it through simple transformers, operators can easily raise or lower the voltage of alternating current.
When stepped up to a higher voltage, alternating current is easy to transport over long wires. When it arrives at its destination, it is stepped down to moderate voltages. Alternating current readily operates lights, motors, and electrical appliances.
Generators in most electric power plants operate at 13,800 volts or higher. Voltage is passed through transformers that step up the voltage to 34,500 volts or higher.
Transmission voltages typically are 115,000, 138,000, and 230,000 volts (called high voltage or HV), and 345,000, 500,000, and 765,000 volts (called extra high voltage or EHV).
You can raise or lower alternating current voltages by using a transformer. As you raise the voltage, you lower the current in a circuit. As you lower the voltage, you raise the current.
A transformer consists of a round or square iron core. Insulated wire wound around one side of the core is called the primary coil. The wire is also wound around the other side, but with a different number of turns.
This is called the secondary coil. The more turns in the secondary coil, the greater the voltage. Current is put through the primary coil, which induces another current in the secondary coil.
If the secondary coil has more turns than the primary coil, the voltage is stepped up. If the secondary coil has fewer turns than the primary coil, the voltage is stepped down.
Here’s a definition of voltage classes provided by the American National Standards Institute.
|Low voltage. A class of nominal system voltages less than 1,000 volts.|
|Medium voltage. A class of nominal system voltages equal to or greater than 1,000 volts and less than 100,000 volts.|
|High voltage. A class of nominal system voltages from 100,000 volts to 230,000 volts.|
3. Using Direct Current
While most current produced by large generators is alternating current, direct current can be produced for special needs. Alternating current can be changed to direct current by putting it through a rectifier.
You probably have noticed that many small appliances and electronic devices have little black boxes that plug into wall sockets. The black boxes contain voltage transformers and, usually, rectifiers for changing house current (AC) to direct current (DC).
Cars use direct current, as do radios and television sets. Radios and TVs have diodes that act as rectifiers to change the alternating current in your house to the direct current they require.
Other uses for direct current include flashlights, electroplating, charging batteries, and separating aluminum from ore.
Electrical Floor Plan of a Room
For requirement 8 of electricity merit badge, you will need to draw a simple floor plan of a room in your house with lights, switches, and electrical outlets penciled in.
First, make a drawing that shows the outlines of a room in your house. Then use the electrical wiring symbols to draw in the overhead and wall lights and to show where electric switches and electrical outlets are located.
Next, ask a parent or guardian to go to the main breaker box and turn off the circuit that supplies power to the room you have chosen. Turn on the lights in the room before the adult flips off the circuit breaker.
If there is more than one circuit breaker that corresponds to the room, note which breaker supplies power to what outlets, lights, and switches by checking them while the power is off.
To the side of your room drawing, make a box, and highlight the circuit breakers that supply power to the room. Briefly note which breaker supplies power to the various electrical devices in the room. You may also want to note the size fuse or fuses with which the room operates. Ask a parent to check the fuse size at the breaker box.
For the Electrical Wiring Symbol you can read the pamphlet that I shared earlier.