Electricity is something we all use every day. It powers our appliances and lights, and is used to transmit information.
Electrical energy comes from atoms. The nucleus of an atom is positively charged, and the electrons circle around it in shells. The outermost electrons are weakly attached to the atom, and can jump to another atom.
Electrical Potential
A charge’s electric potential is its energy to do work. If you push a positive test charge against the arrows of an electric field, it gains energy, and its potential increases. But when you let the charge fall back towards its negative terminal, it loses energy and returns to a lower electric potential.
Just as mass in close proximity has gravitational potential energy, charges in an electric field have potential energy to interact. If the charge were allowed to flow freely, that energy would be converted into kinetic energy and work could be done. But when a conductor limits the movement of charges, its resistance is added to the electric potential and this energy is lost. In metals, the electric potential is corrected by the atomic environment, and this is the value that is read by a voltmeter. An idealized point charge has an electric potential proportional to 1 / r, where r is the distance from the point.
Electrical Current
Current is the amount of charged particles (such as electrons) that drift steadily past a single point in a closed electrical circuit in one second. It is the rate at which energy flows through a circuit, and can be direct or alternating. It is measured in amperes, or amps.
Direct current is the kind of electric current produced by batteries and supplied to household electrical receptacles. Alternating current, on the other hand, is a flow of electric charge that reverses direction periodically, creating a waveform like a sine wave. It is the type of electric power most commonly used in electronic devices and motors.
Electric current flows only in conductors that offer little resistance to the movement of electrons. Examples include the metal wires in overhead power lines and the smaller wires within electrical and electronic equipment. It also occurs in living things, such as the flow of ions in nerves and neurons, which is responsible for thought and sensation.
Electrical Wires
Electric wires are a metal conductor that transports electricity, usually copper or aluminum. They are also sheathed in an insulator such as plastic. The sheath protects the conductive metal from corrosion, mechanical damage and human contact. Different insulators can be used for different purposes. The thickness of the conductor (also known as its gauge) determines the amount of current that can flow through it.
The electrical wiring in homes and structures is often color-coded to avoid confusion and reduce the risk of accidents. These codes may be mandatory or voluntary depending on local rules and regulations.
The most common type of electrical wire is a single-conductor insulated wire. It is typically black or red in color. The red wire is used as a power feed to a 240-volt outlet and is commonly seen in ceiling fans and outlets controlled by switches. Single-conductor insulated wires are available in both solid and stranded forms. The most common types of stranded wires are jumper and hook-up wires.
Electrical Circuits
An electrical circuit is a closed path for electric current to follow. It consists of a power source, conductors (such as wires) and a switch.
Every electric circuit needs a power supply, such as a battery. It also needs a light bulb and wires. The light bulb glows when current passes through it, which shows that the electric circuit is working.
The voltage of the battery and the resistance of the light bulb affect the electric current. Understanding these conditions and how they can change is the key to designing an electrical circuit.
The best way to teach students about electric circuits is with simple circuit diagrams and models. They can use these tools to build their own circuits and learn the different symbols that are used in a circuit diagram. They can then apply these concepts to real-world electricity systems. This is how they can understand how the electricity that runs from their house to their laptop works. Star Plus Electrical
