These DAV Class 6 Science Notes and DAV Class 6 Science Chapter 11 Notes – Electric Currents and Circuits act as excellent revision resources, particularly in preparation for board exams.
Electric Currents and Circuits Class 6 DAV Notes
→ Structure of Electric Torch:
The electric torch has three main parts:
(1) an electric bulb
(2) an electric cell or a combination of electric cells (a battery) and an arrangement for housing them
(3) an (on/off) switch.
When the switch is pressed, electricity starts to flow from the electric cells to the electric bulb. That is how the electric torch functions.
→ Electric cell: Electric cell is a device which produces electricity because of chemical reaction.
→ Structure of a Dry Cell: A dry cell is made up of a zinc vessel which also works as the negative pole of the cell. A carbon rod is in the centre which works as the positive pole of the cell. A muslin bag is kept surrounding the carbon rod. The muslin bag is filled with manganese dioxide. The zinc vessel is filled with ammonium chloride.
→ Battery: A group of cells is called a battery.
→ LED: Light Emitting Diode is a simple device which emits light when electric current passes through it. LED can glow even in the presence of weak current.
→ CFL: It stands for Compact Fluorescent Lamp. A CFL consumes less electricity than bulb.
Electric Bulb: An electric bulb is made of glass. There is a glass mount in its centre on which some support wires are attached vertically. The filament is fixed at the top of support wires. The filament is made of tungsten. Tungsten has a very high melting point which makes it ideal for a bulb filament. The filament is connected to two terminals of the bulb. An inert gas (argon) is filled inside the bulb to prevent accidental fire.
→ Working of electric bulb: When electric current flows through the bulb, the filament heats up, and thus produces light.
→ Electric Current: The flow of electric charge is called electric current. Electric current always flows from positive terminal to negative terminal.
→ Electric Circuit: The closed path through which electric current flows is called electric circuit. It usually contains following components:
- A source of electricity (cell/battery).
- Connecting wires; which provide the path for electric current.
- A switch or a device which can start or stop the flow of current.
→ Electric Switch: It is a device which is used for starting or stopping electric supply as and when required.
→ Symbols in Electric Circuit: Different components of an electric circuit are shown by different symbols. Symbols make it easy to make and understand a circuit diagram.
→ Conductor: A material which allows electric current to pass through it is called conductor, e.g. copper, aluminium, iron, etc.
→ Insulator: A material which does not allow electric current to pass through it is called insulator, e.g. wood, asbestos, plastic, etc.
→ Precautions to be taken while handling electricity:
- Never touch electrical connections or devices with wet hands. Normal water is a good conductor of electricity.
- So, touching an electrical connection with wet hands can lead to electric shock.
- When a device is connected to the mains, do not open it.
- Always respect the ‘Warning’ or ‘Danger’ sign near an electrical installation.
- If you have any doubts about an electrical appliance, contact the manufacturer or an electrician.
- When working with an electrical appliance, use rubber glove.
- Wear a rubber sandal, while handling an electrical appliance.
→ Electric current: The flow of electric charge is called electric current.
→ SI Unit of Electric Current: Ampere Cell: A device which produces electricity.
→ Battery: A group of cells is called a battery.
→ Dry cell: A dry cell has dry chemicals inside it.
→ Electric circuit: The closed path through which the electric current flows.
→ Circuit diagram: The diagrammatic representation of electric circuit.