How Electricity Works: Amps Voltage and Resistance
Author: John Published Under: Technology
An electric charge is made up of millions of different electrons. Current is a measurement of the number of moving particles in an electrical charge. Amps and Voltage are other measurements used to describe the properties of an electrical charge.
Amps and Ampere
Since current is measured by the number of charge carriers that pass through a single point, it could be represented as ECUs, but this number would be incredibly high. Instead, current is usually described in coulombs per second(C/s.) A current of 1 C/s is classified as an ampere(A,) which is the standard measurement of current.
Voltage
In order for electrical current to flow, it must be pushed by something, which is often caused by a buildup of electrostatic charge, like is seen in a lightning strike. When a charge is built up, it creates voltage, which describes the currents electrical potential. Voltage is often described as volts(V) and is sort of like the amount of pressure on the current.
In the United States, most home electrical outlets have a voltage between 110V and 130V, which is not steady, but instead fluctuates many times a second. On average, it usually ends up being about 117V.
A car battery, on the other hand, operates at closer to 12V and is much steadier than an electrical outlet.
Static electricity, such as from walking on a carpet, can end up being several thousand volts, with lightning being representative of millions of volts.
It is possible to have voltage, without having current, as can be seen in clouds prior to a lightning discharge. This is one of the reasons people will sometimes say, “Current Kills, not Voltage,” but this is a little bit misleading. This is because all it takes to turn voltage to turn into current is a clear path.
Volts vs Current
When voltage is steady and doesn't have alternating polarity, the current of an electrical component is directly related to the voltage. As a result, in this example, if voltage doubles, current doubles.
In practice, however, the relationship is not usually directly proportional, as most objects conductivity changes with the current. For instance, a light bulb burns hotter when receiving a lot of current and dimmer when less current is applied. As the filament changes, the conductivity is directly affected.
However, some objects are designed to have constant conductance, even across different voltage.
Resistance
There are few machines and properties that operate completely efficiently, with electricity being no exception. The resistance of an object is how much opposition it gives to an electrical current.
Good conductors, such as silver, aluminum, and copper, have relatively low resistance, which is what makes them good conductors.
Insulators, such as plastic, have high resistance, which is what makes them poor conductors and good insulators.
The amount of resistance an object has is measured in ohms, which is represented by the Greek Omega Symbol( Ω.)
The more ohms something has, the greater its resistance. It is important for electrical systems to have low resistance, or low ohms, as the higher the oms, the more hot the element gets. This heat is generated as the resistance converts the electrical energy into heat.
Dealing with Resistance
Even the best conductors, such as silver, have some resistance, so it is not practical to expect to have something with 0ohms. While, by removing all heat from an object, it is possible to create something that is a perfect conductor and has no resistance, in practice this is not really possible.
The same can be said of insulators as well, because even the best insulators are not completely resistant, but actually allow some electrical current through.
It is important to keep this in mind, because in practice, it is possible to operate at very low ohms or very high ohms, but few items tip the scale at being 100% conductors or 100% insulators.