# Electricity and Circuits

## Introduction

Throughout this smore, you will be able to gain an understanding about and answers that relate to:

• Electricity
• The Ohms Law
• Circuits

## Electricity

Electricity is a form of energy composed of charged particles such as electrons and protons.

Electricity and everything around us is composed of atoms. Atoms are made up of 3 parts: protons, neutrons and electrons. Protons have a positive charge. They are located in the middle of the atom and do not move. It can also be referred to as the nucleus. Neutrons have no charge. They are neutral and part of the nucleus of an atom with the protons. Electrons are the smallest part of the atom. They are not part of the nucleus of the atom, instead they the move around in circles outside the nucleus.

When electrons flow, it's called an electrical current. In electric circuits this charge is often carried by moving electrons in a wire.

Static electricity is the result of an imbalance between negative and positive charges in an object. It is produced when two objects are rubbed together.One object will have a positive charge and the other a negative charge. Rubbing the objects quickly, like when you rub a balloon fast over something or your feet on the carpet, will build up a large charge.

## Ohms Law

The Ohm's Law states that the current through a conductor between two points is directly proportional to the potential difference across the two points.
The letter "V" in the Ohm's Law stands for voltage, "I" stands for current, and "R" stands for resistance. When "R" and "I" are multiplied, you will get "V". If you divide "V" by "I", you will get "R", the same applies if you want to find "I", you divide "V" by "R".

If the voltage increases and the current is constant, then the current will increase. If the resistance increases and the voltage is constant, then the current will decrease.

## Circuits

A circuit is a closed loop that electrons can travel in. Current flows from a high voltage to a lower voltage in a circuit.

The 5 parts that make up a single series current are a battery, a resistor, power source, light bulb and a switch.

A resistor is used to limit the current flowing in a circuit. Too much current flowing through a component can damage it.

A parallel circuit is a circuit that follows the load and then back to the source in many paths. If one component breaks down, the rest will continue to operate. A series circuit only goes one way no matter what. If one component breaks down, so will the rest.

Conductors are materials which allow charge to flow through a circuit easily. The most common conductors are made out of metallic materials. Insulators are materials which prevent charges from flowing through a circuit. They can be forced to conduct electricity if the charges have enough energy.

A conventional current flow is an electric current that flows from positive to negative. Electron current flow is when an electric current that flows from negative to positive.