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Physics for Kids

Electric Current

Current is the flow of an electric charge. It is an important quantity in electronic circuits. Current flows through a circuit when a voltage is placed across two points of a conductor.

Flow of Electrons

In an electronic circuit, the current is the flow of electrons. However, generally current is shown in the direction of the positive charges. This is actually in the opposite direction of the movement of the electrons in the circuit.

How is current measured?

The standard unit of measurement for current is the ampere. It is sometimes abbreviated as A or amps. The symbol used for current is the letter "i."

Current is measured as the flow of electric charge over time past a given point in an electric circuit. One ampere is equal to 1 coulomb over 1 second. A coulomb is a standard unit of electric charge.

Calculating Current

Current can be calculated using Ohm's Law. It can also be used to figure out the resistance of a circuit if the voltage is also known or the voltage of a circuit if the resistance is known.

I = V/R
where I = current, V = voltage, and R = resistance

Current is also used to calculate power using the following equation:

P = I * V
where P = power, I = current, and V = voltage.

AC versus DC

There are two main types of current used in most electronic circuits today. They are alternating current (AC) and direct current (DC). Electromagnetism

Current also plays an important role in electromagnetism. Ampere's law describes how a magnetic field is generated by an electric current. This technology is used in electric motors.

Interesting Facts about Current Activities

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More Electricity Subjects

Circuits and Components
Intro to Electricity
Electric Circuits
Electric Current
Ohm's Law
Resistors, Capacitors, and Inductors
Resistors in Series and Parallel
Conductors and Insulators
Digital Electronics
Other Electricity
Electricity Basics
Electronic Communications
Uses of Electricity
Electricity in Nature
Static Electricity
Electric Motors
Glossary of Electricity Terms

Science >> Physics for Kids

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