# Electrical quantities, what are they and what are they?

What are the main electrical quantities? In this article, we will talk about voltage, current, resistance, and electrical power. Understand what are your units of measure, and how each of these quantities behaves in the series or parallel circuit. Come on, guys!

## What is the electric current?

The electric current is characterized as the ordered flow of electric charges, that is, they move in an oriented way. It is one of the fundamental magnitudes of Physics because without the electric current, no electrical or electronic device would work!

## How does the movement of cargo arise?

Free electrons are stimulated to move by the conductor, generating electrical current. This is because of the difference in electrical potential established between the conductor tips.

The difference in electrical potential of a conductor is established from an electric field that passes through that particular material, forming different levels of potential energy, resulting in the voltage necessary to generate the movement of electrical charges.

Know and understand the main electrical quantities!

## What is electrical power?

The definition of electrical power is basically the speed with which the equipment converts electrical energy into work. In case you don’t know, the watt (W) is the unit of power in the international measurement system.

In electrical equipment, the power indicates the amount of electrical energy that is transformed into another type of energy per unit of time. The microwave, for example, needs a certain amount of watts (power) to generate the work, which in the case of this equipment is heating.

## What is electrical resistance?

The electrical resistance is characterized as the ability of a body to oppose the passage of electric current. Understand that the electrical resistance can vary according to the width, length, environmental conditions and nature of the conductor material.

Here in the world of electrical, we have already talked about electrical resistance, and we explained how temperature can interfere with a conductor’s electrical resistance. In the international system, the unit of measurement of resistance is Ohm, which is a tribute to the German George Simon Ohm.

## What is the electrical voltage?

The electrical voltage is characterized as a difference between the electrical potential of two points. In summary, we can say that the electrical voltage is the force necessary to move the electrons, creating an electric current.

Know that the potential difference can represent a source of energy (electromotive force). It can also represent a loss of energy or storage (voltage drop).

• Continuous tension – It means that it does not change polarity in time. The battery is a great example of continuous voltage operation because the battery’s polarity will always be the same over time.
• Alternating voltage – In the case of alternating voltage, the polarity will be alternated according to the frequency. In the socket, the normal frequency is 60Hz, so it means that the polarity of this voltage alternates 60 times per second.

## Electrical quantities: Units of measure

The International System (SI) also defines the units of measurement for these electrical quantities, which are:

• Voltage = Volts (V)
• Current = Ampere (A)
• Power = Watt (W)
• Resistance = Ohm (Ω)

In this video below the Mundo da Elétrica channel, you can see many more tips and information about electrical quantities, worth checking out.

## Electrical quantities: Basic formulas

The two main formulas related to electrical quantities are:

• P = V * I – The power can be found using the formula. Power is equal to the voltage multiplied by the current.
• V = R * I – The voltage can be found using the formula. Voltage is equal to the resistance multiplied by the current.

From these formulas, you can manipulate the variables and come up with other formulas that are also important. When manipulating the variables, you find the formulas of the other electrical quantities such as (V = P / I) which is Voltage is equal to the power divided by the current.

If you have any questions about these electrical quantities, leave them in the comments and we will answer them.