CBSE Notes Class 6 Science Chapter 9 Electricity and Circuits

Electricity is a form of energy that powers many things we use daily, like lights, fans, and computers. It flows through tiny particles called electrons in wires. Circuits are essential for safely guiding this flow of electricity. They let us control where electricity goes, enabling us to power everything from simple toys to complex gadgets.

In short, electricity needs a path to flow, and circuits provide that path. With cells, switches, conductors, and insulators, we can use electricity safely in our everyday lives.

1.0Electric Cell

• An electric cell is a device that generates electricity through a chemical reaction inside it. Once the chemicals in the cell are exhausted, it stops producing electricity. At this point, the cell needs to be replaced with a new one.
• Structure-An electric cell has a metal cap and a metal disc at its ends. The metal cap serves as the positive terminal, while the metal disc acts as the negative terminal.
• Uses-Devices such as alarm clocks, wristwatches, transistor radios, cameras, and many others use electric cells. In a torch, the electric cell supplies the electricity needed to light the bulb.

NOTE-Never connect the terminals of an electric cell directly, as this causes the cell to drain quickly and eventually stop working.

2.0Electric Bulb

An electric bulb lights up when electricity flows through it and is widely used in homes, schools, and other places to provide illumination.

Parts of a Bulb

1. Glass Case-It is the outer covering of glass in a bulb which prevents oxygen in the air from reaching the hot filament.
2. Filament-The filament of the bulb is made up of metallic thin wire( tungsten filament) that gives off light.
3. Terminal-Every bulb has two terminals one is connected with the negative terminal of the cell and another is connected with the positive terminal of the cell.

3.0Electric Circuit

• When electric components like bulb, cells, wires, etc. are connected  with each other, the setup is called an electric circuit.
• A bulb lights up only when electric current passes through the circuit.

4.0Fused

An electric bulb is said to be fused when it is connected to a cell in a circuit but does not glow. An electric bulb may fuse due to many reasons like if the filament of the bulb is broken the bulb does not glow.

5.0Electric Switch

A switch is a basic device that either interrupts the circuit or closes it to allow current to flow.

6.0Conductors and Insulators

• Conductors-The materials which allow the electric current to pass through them are conductors of electricity.

For Examples-Coins, Metal wire, a sewing needle and iron nail

• Insulators-Materials that prevent the flow of electric current are known as insulators.

For Example- Thermocol, wood and plastic

NOTE-The human body is a conductor of electric current, we have to be careful while handling electrical appliances.