Electricity and Circuits

You were sitting at your study table, studying for your science exam tomorrow and the current goes off. You wanted the electricity to come back as soon as possible. Such incidents keep happening and that’s when you realise how important electricity is for you.

Life without electricity is next to impossible for us to imagine. Most of the devices such as tube lights, fan, refrigerator, T.V, Laptop, etc are only used if you have electricity running through them.

Contents

What is Electricity?

Electricity is nothing but the flow of electric charge (electrons). For better understanding, let’s produce an electric current by making an electric circuit.

Activity 1

With the help of an adult, you will make an electric circuit. For that, you will need a transparent bulb, thin wires, electric cell and electric switch.

Connect the two ends of the electric cell with the thin wires. Take one of the connected wire and attach a switch, following connect another thin wire to it. Then, take the other connected wire that is connected to the cell and also the wire that is connected to switch and connect their ends to an electric bulb.

Now allow the electricity to flow through the circuit by turning the switch on.

Look at the bulb, you will see that the thin filament is glowing and giving out light.

Why does that happen??

The bulb started glowing when you completed the electric circuit. This allowed the electricity to flow from a source of electric current. The filament inside the bulb heats up continues to heat up so much that it begins glowing.

In this activity, we had a source of electricity. Any guesses, what was it that produced electricity?

Well if your answer is Electric Cell, then you are right. There are different types of electric cells available, but we use a Dry Cell.

Electric Cell

An electric cell is a source of electricity. It produces electricity because of the chemicals stored inside it.
When the chemicals inside are used up, it stops producing electricity and needs to be replaced with a new cell.
All electric cells two terminals; a positive terminal at the metal cap and a negative terminal at the other end.

Electric Circuit

When you connect one terminal of the electric cell to the other terminal, through wires which are connected to a bulb to make it glow, then such an arrangement is called an electric circuit.
In simple words, a continuous and closed path of an electric current is called an electric circuit.
In a closed electric circuit, the electric current passes from the positive terminal of the electric cell to the negative terminal.

Electric Bulb

An electric bulb is a source of light only when electricity is passed through its terminals.
It has a filament that is connected to its terminals. This filament heats up and glows when electricity passes through it.

But if in any case, if the bulb does not glow in a closed circuit then it might be fused or the other reason might be the break in the circuit.

Electric Switch

An electric switch is a link that connects the cell and bulb or completes the circuit. In simple words, it is a device that either breaks the circuit or completes it.
A switch is used to open or close an electric circuit.

Electric Torch

An electric torch is a perfect example of a simple electric circuit. It usually has one or more dry cells inside it, which are connected through a switch to a small bulb.
This bulb emits light when the switch is turned on completing the circuit. And when the switch is turned off, the circuit breaks and the light goes off too.

Conductors

Materials through which electricity can flow are called conductors. This happens because when current passes through them, the electrons can flow within the conductor from one particle to the other.

For example Metal : Water, Humans, etc.

Insulators

Insulators are materials that do not allow the flow of electricity through them. We use them as covering on electrical wire and switches, so that we don’t get electrics shock.

For example : Plastic, Wood, Glass, etc.