Electric Current and Its Effects

Electric cell

• An electric cell has two lines.
• One is shorter and the other line is longer.
• The longer line represents the positive terminal.
• The shorter line represents the negative terminal.

What is a Battery?

• Combination of two or more cells is known as the battery.
• In a battery the positive terminal of one cell is connected to the negative terminal of the other cell.
• Battery is a source of energy which converts chemical energy into electrical energy.
• They are used in remotes, electronic games, tv etc..
• The batteries used in trucks and inventors are also made from cells. They are made from many cells and are thus termed as a battery.

Electric Current

• The flow of electrons or the flow of charge is known as Electric Current.
• The SI unit of Current is Ampere (A).
• Electric Current is a scalar quantity.

Electric Circuit

• Electric Circuit is a circuit with various electrical components in which there is a flow of electric current.
• The various components of electric circuit are an electric cell, an electric bulb, connecting wires and a switch.
• The thin wire in the bulb is known as filament.
• When the switch is in on position the circuit from the positive terminal to the negative terminal is complete and is considered as a closed circuit.
• When the switch is in off position the circuit is incomplete and is said to be open.
• There is no flow of current when the circuit is open.

Heating effect of electric current

• When the electric current passes through any conductor it gets hot. This phenomenon is known as the heating effect of electric current. For example; An iron becomes hot when we switch on it.
• The amount of heat produced in any conductor depends on it’s material, length and thickness. That’s why we don’t use same conductor for various purposes.
• Some wires start melting when a large amount of electric current is passed through them. Electric fuses are made with the help of these wires.
• If the wire exceeds the given  safe limit, the wires may become overheated and can cause fire.
• MCBs( Miniature circuit breakers) are used instead of fuses as it gets automatically turned off when the current exceeds the safe limit.

Magnetic Effect Of Electric Current:

• When a magnetic field is created around a conductor when electric current is flowing through it then this phenomenon is called as the Magnetic effect of electric current.
• When electric current passes through a wire it behaves like a magnet.

Electromagnets:

• An electromagnet is a magnet made up of soft core by the passage of electric current.
• They are made strong to lift up various loads.

Uses of electromagnets:

• They are used to separate magnetic material from the jink.
• Doctors use them to remove small pieces of magnetic material stuck into the eye and are also used in a MRI.
• Many toys have magnetic material inside them.
• They are used inside speakers.