What is electricity? and its description
What is electricity?
Electricity is the most widely used source of energy in our households. Most of the appliances work by using current supplied by the mainline. There are many things like torch, camera, clock, etc., that work on the electric cells.
A fundamental form of energy observable in positive (+ve) and negative (-ve) forms that occur naturally or are produced as in generator and that is express in terms of the movement and interaction of electrons. In other words, The flow of charge in a closed path carrying energy from the power supply to the different electrical components in the circuit is known as electricity.
The presence of an electric charge, which can be either positive or negative charge, produces an electric field. The movement of electric charge is an electric current and produces a magnetic field.
Electricity is at the heart of many modern technologies, for example, electric power where electric current is used to energize equipment.
If we bring a plastic comb near very tiny pieces of paper, it will not have any effect on them. When the comb is first rubbed with dry hair and then brought near the tiny pieces of paper, we find that the comb now attracts the pieces of paper towards itself. These observations are explained by saying that initially, the comb is electrically neutral so it has no effect on the tiny pieces of paper. If the comb is rubbed with dry hair, then it gets an electric charge. This electrically charged comb exerts an electric force on the tiny pieces of paper and attracts them.
What is the electric current?
The rate of flow of electric charge in a particular direction is called an electric current. SI unit of current is Ampere.
Current, I = Charge(Q)/Time(t)
Current Electricity
The Branch of physics which deals with the study of charge in motion is known as current electricity.
• Flow of charge in closed circuit
• Direction of flow of positive charge (+ve) in the direction of conventional current.
• Direction of current is opposite to the direction of flow of electron in a circuit.
What is an electric charge?
Electric charge is a fundamental property of the body due to which two bodies strongly attract or repel each other. SI unit of charge is the coulomb. A proton carries a positive charge of 1.6 x 10–19 C whereas an electron carries a negative charge of 1.6 x 10–19 C. There are two types of electric charge: positive and negative (carried by protons and electrons respectively).
Types of Electric Charge
• Positive Charge
• Negative Charge
(i) Opposite charges (or Unlike charges) attract each other. For example, a positive charge attracts a negative charge.
(ii) Similar charges (or Like charges) repel each other. For example, a positive charge repels a positive charge; and a negative charge repels a negative charge.
SI unit of electric charge ‘coulomb’ © is equivalent to the charge contained in 6.25 x 1018 electrons. Thus, a coulomb is a very big unit of electric charge.
Electrical cell
In an electric cell, the chemical energy is converted into electrical energy. When the chemical of the cell is used up, it stops working.
An electrical cell consists of a positive (+) and a negative terminal (-). When the cell is in use in an electric circuit, the current passes from one terminal to the circuit and back to the other terminal of the cell.
The positive terminal of the cell should never be directly joined to the negative terminal of the cell as it rapidly consumes all the energy and the cell gets wasted.
A single cell has a voltage of 1.5 volts. When a higher voltage is required, two or more cells are joined together. This is called a battery.
In a battery, the positive terminal of one cell is connected to the negative terminal of the second cell, and so on. The domestic supply of electricity in India has a voltage of 220V.
What is an electric circuit?
The electric circuit is a closed path in which current flows out of the cell, passes through various conductors on the way, and comes back to the other terminal of the cell. If the continuity is broken, the current stops moving.
Electric bulb
An electric bulb may be joined in the circuit. The currents passing through the bulb heats its filament and it starts glowing giving out light. The bulb works as long as the filament is intact.
If the filament is broken, the bulb does not work. We may control the circuit with the help of the switch.
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