How does voltage work

I'm going to draw a mountain here. Here's some mountain-side with snow on it. And I'm going to put a mass here, here's a mass of some mass M. And it was lifted up to the top of the hill somehow, by a ski lift, by a mountain climber, something like that.

And if I put it on top of the mountain and I let it go, the potential energy that it has is going to be dissipated as kinetic energy and that mass is going to roll down the hill to here. And as it does, it could do some work. It could hit some trees, let's draw a tree. And it could run into a tree and knock that tree around. It could hit a bear, it could bounce off rocks, all kinds of things, so that's a mass rolling down a hill.

With electricity, we measure the amount of charge flowing through the circuit over a period of time. Current is measured in Amperes usually just referred to as "Amps". An ampere is defined as 6. Amps are represented in equations by the letter "I".

Let's say now that we have two tanks, each with a hose coming from the bottom. Each tank has the exact same amount of water, but the hose on one tank is narrower than the hose on the other. We measure the same amount of pressure at the end of either hose, but when the water begins to flow, the flow rate of the water in the tank with the narrower hose will be less than the flow rate of the water in the tank with the wider hose.

In electrical terms, the current through the narrower hose is less than the current through the wider hose. If we want the flow to be the same through both hoses, we have to increase the amount of water charge in the tank with the narrower hose. This increases the pressure voltage at the end of the narrower hose, pushing more water through the tank.

This is analogous to an increase in voltage that causes an increase in current. Now we're starting to see the relationship between voltage and current.

But there is a third factor to be considered here: the width of the hose. In this analogy, the width of the hose is the resistance. This means we need to add another term to our model:. It stands to reason that we can't fit as much volume through a narrow pipe than a wider one at the same pressure.

This is resistance. The narrow pipe "resists" the flow of water through it even though the water is at the same pressure as the tank with the wider pipe. In electrical terms, this is represented by two circuits with equal voltages and different resistances. The circuit with the higher resistance will allow less charge to flow, meaning the circuit with higher resistance has less current flowing through it. This brings us back to Georg Ohm.

Ohm defines the unit of resistance of "1 Ohm" as the resistance between two points in a conductor where the application of 1 volt will push 1 ampere, or 6. This is called Ohm's law. Let's say, for example, that we have a circuit with the potential of 1 volt, a current of 1 amp, and resistance of 1 ohm.

Using Ohm's Law we can say:. Let's say this represents our tank with a wide hose. The amount of water in the tank is defined as 1 volt and the "narrowness" resistance to flow of the hose is defined as 1 ohm. Using Ohms Law, this gives us a flow current of 1 amp. Using this analogy, let's now look at the tank with the narrow hose. Because the hose is narrower, its resistance to flow is higher. Let's define this resistance as 2 ohms.

The amount of water in the tank is the same as the other tank, so, using Ohm's Law, our equation for the tank with the narrow hose is. But what is the current? Because the resistance is greater, and the voltage is the same, this gives us a current value of 0. Electricity acts similarly: the concept of water height is analogous to electric potential, and electricity flows from places with high electric potential to places with low electric potential. The potential difference between two places can be expressed as a voltage.

Resistance indicates the difficulty with which electricity flows. Imagine a water main. As the pipe grows smaller, resistance increases, and it becomes more difficult for the water to flow; at the same time, the strength of the flow increases.

By contrast, as the pipe grows larger, water flows more readily, but the strength of the flow decreases.

A similar situation applies to current. Resistance and current are proportional to voltage, meaning that as either increases, so too will voltage. Multimeters multi-testers are used to measure voltage. In addition to voltage, multimeters can perform continuity checks and measure parameters such as current, resistance, temperature, and capacitance. Multimeters come in both analog and digital variants, but digital models are the easiest to use without mistakenly reading values since they display values directly.

To measure voltage with a multimeter, you connect positive and negative test leads and select a voltage measurement range.

Voltage is the cause and current is its effect. Voltage can exist without current. Voltage gets distributed over components connected in series. In a parallel connection Current gets distributed over components connected in parallel. Voltages are the same across all components connected in parallel. Relationship Between Voltage and Current Current and voltage are two fundamental quantities in electricity.

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