Switches offer wired connections to desktop computers, wireless access points (APs), printers and industrial equipment. They reduce congestion on a network and increase the bandwidth available to devices.
Every source of electricity has two sides—positive and negative. When a free electron catches up to an atom’s positive charge, it ejects another valence electron and creates more electricity.
What is electricity?
Electricity is a phenomenon associated with stationary or moving electric charges. In most cases, these charged particles are electrons, which carry a negative charge. When these electrons move, they create a current of electricity that can do work for us.
To make electricity flow, we need a complete circuit. This includes a power source, conductors and a load. When we plug a light or electrical device into a socket, we’re completing the circuit, allowing electrons to travel from the power source, through the conductors and into the load to perform work.
There are two types of electricity: static and current. Static electricity occurs when there is an imbalance of positively and negatively charged atoms. Electrons then jump from atom to atom, releasing energy. Current electricity is a constant flow of electrons and can be either direct or alternating. Direct current is the type produced by batteries and required by most electronic devices. Alternating current, on the other hand, flips direction back and forth many times each second, enabling it to travel long distances—like from power plants to your building’s breaker box and then into your household appliances.
What is a circuit?
A circuit is any fixed path through which electricity can flow and do work. The circuit can include any combination of current source, conductors and a load. Electrons leave the power source, travel along the conductors (such as wires), go through the load and perform work, then return to the power source.
A light bulb is a good example of an electrical load. When a battery is connected to a wire and a light bulb, an electric current flows through the bulb. The fact that the bulb lights and remains lit is evidence that a circuit is established.
The components of a circuit are joined together using copper, which is an excellent conductor of electricity. Students can build their own simple circuits on a classroom circuit board with crocodile clips, paper, batteries and light bulbs. Students should also practice recognizing the symbols used in circuit diagrams. Then, they can use their knowledge of voltage and current to troubleshoot a problem with a powered circuit using a multimeter.
What is a voltage?
The difference in electric potential between two points on a circuit is called voltage. Voltage is the “pressure” that drives electrons to flow through a conducting material and enable them to do work such as illuminating a lamp. It is derived from the electric potential energy of an electricity source and named after Italian physicist Alessandro Volta (1745-1827) who invented the voltaic pile, the forerunner of today’s household battery.
Voltage is measured in volts (V) which is a derived SI unit that specifies the amount of force pushing flowing electrons at a constant rate (one coulomb per second). An electrical outlet in your house has 120 V across the two holes.
It is important to distinguish between current and voltage. Current is the actual flow of electrons while voltage indicates how much potential energy, or potential difference, exists between two points in a closed loop path. The higher the voltage, the stronger the potential to drive current and do work.
What is a current?
Electric current is the movement of electrons from one point to another. It is measured in amperes (A). When current is combined with volts and resistance, it is possible to calculate power.
There are two types of currents, direct and alternating. Direct current does not change its direction of travel over time, and is the type used in household appliances. Alternating current, on the other hand, does change its direction over time and is used in motors, generators, lights, etc.
In order for electric current to flow, there must be a closed conducting loop and an energy source that produces voltage. Voltage creates pressure on the electrons, which channelizes them to flow in a specific direction. It is the same principle that causes water to flow down a river and generates powerful ocean currents like the Gulf Stream. The unit of measurement for current is the ampere, which is defined as 1 coulomb of electrons passing a particular point in a circuit in a second. Star Plus Electrical