# Which correctly expresses the relationship between voltage current and electrical power

### Ohm’s Law - How Voltage, Current, and Resistance Relate | Ohm's Law | Electronics Textbook

Resistance to alternating current is more properly called impedance but, The relationship between current, voltage and resistance is expressed by Ohm's Law. The flow of electricity through this circuit is further illustrated by analogy to the. The rate at which electrical energy is converted to another form of energy .. Which correctly expresses the relationship between voltage, current, and resistance. The first, and perhaps most important, relationship between current, voltage, and An electric circuit is formed when a conductive path is created to allow free Voltage is a specific measure of potential energy that is always relative between two points. This opposition to motion is more properly called resistance.

We saw these concepts in action with the garden hose. Increasing the pressure caused the flow to increase, but getting a kink in the hose increased the resistance, which caused the flow to decrease. Using this diagram is an easy way to solve equations. The way the equation is written here, it would be easy to use Ohm's law to figure out the current if we know the voltage and the resistance.

But, what if we wanted to solve for the voltage or the resistance instead? One way to do this would be to rearrange the terms of the equation to solve for the other parameters, but there's an easier way. The diagram above will give us the appropriate equation to solve for any unknown parameter without using any algebra.

To use this diagram, we simply cover up the parameter we're trying to find to get the proper equation.

## Ohm's Law: Definition & Relationship Between Voltage, Current & Resistance

This will make more sense once we start using it, so let's do some examples. Ohm's Law in Action Below is a simple electric circuit that we'll use to do our examples. Our voltage source is a battery that is connected to a light bulb, which provides resistance to the electric current. To start off with, let's say our battery has a voltage of 10 volts, the light bulb has a resistance of 20 ohms, and we need to figure out the current flowing through the circuit.

Using our diagram, we cover up the parameter that we're trying to find, which is current, or i, and that leaves us with the voltage, v, over the resistance, r.

In other words, to find the current, we need to divide the voltage by the resistance.

## Current, Voltage and Resistance

Doing the math, 10 volts divided by 20 ohms results in one half ampere of current flowing in the circuit. To find the current, divide the voltage 20 volts by the resistance 20 ohms. Next, let's increase the voltage to see what happens to the current. We'll use the same light bulb but switch to a volt battery. Using the same equation as before, we divide 20 volts by 20 ohms and we get 1 amp of current.

### Current, Voltage and Resistance - Humane Slaughter Association

The amount of current in a circuit depends on the amount of voltage available to motivate the electrons, and also the amount of resistance in the circuit to oppose electron flow.

Just like voltage, resistance is a quantity relative between two points. Volt, Amp, and Ohm To be able to make meaningful statements about these quantities in circuits, we need to be able to describe their quantities in the same way that we might quantify mass, temperature, volume, length, or any other kind of physical quantity.

Here are the standard units of measurement for electrical current, voltage, and resistance: Standardized letters like these are common in the disciplines of physics and engineering, and are internationally recognized.

Each unit of measurement is named after a famous experimenter in electricity: The amp after the Frenchman Andre M. The mathematical symbol for each quantity is meaningful as well. Most direct-current DC measurements, however, being stable over time, will be symbolized with capital letters. Coulomb and Electric Charge One foundational unit of electrical measurement, often taught in the beginnings of electronics courses but used infrequently afterwards, is the unit of the coulomb, which is a measure of electric charge proportional to the number of electrons in an imbalanced state.

One coulomb of charge is equal to 6,,, electrons. Cast in these terms, current is the rate of electric charge motion through a conductor. As stated before, voltage is the measure of potential energy per unit charge available to motivate electrons from one point to another. Defined in these scientific terms, 1 volt is equal to 1 joule of electric potential energy per divided by 1 coulomb of charge.

Thus, a 9 volt battery releases 9 joules of energy for every coulomb of electrons moved through a circuit. These units and symbols for electrical quantities will become very important to know as we begin to explore the relationships between them in circuits.