What is Electricity?

A crucial source of energy in today’s society is electricity. It is used in business, transportation, and our homes. For instance, our home’s lighting, fans, and heating systems are all powered by electricity. Electric trains are powered by electricity, which is also used to run a range of devices in industry and in the transportation sector.

The flow of little electrons is what generates electricity. Positive or negative charges can be present in electrons. Negative and negative charges repel one another, while positive and positive charges attract one another.

When two distinct materials are rubbed together, electricity can be produced. For instance, if we brush a silk fabric against a glass rod, the silk cloth will become positively charged and the glass rod would become negatively charged.

Electricity can be used for a variety of purposes, including running equipment, appliances, and lights. It can be used for information transmission and communication as well.

Electric Charge

One coulomb is the amount of electric charge that pushes or pulls with a force of 9 × 10⁹ newtons when another equal charge is placed 1 meter away from it.

The coulomb (C) unit of electric charge. Protons, which are positively charged particles, and electrons, which are negatively charged particles, are present in all matter.

Through contact, friction, or induction, we can move objects close to one another without really touching them to transfer charge from one to the other. The charges will flow from the object with more charge to the object with less charge until they are equal when two objects with different charges are brought together. Static electricity is what we refer to as.

As an illustration, the balloon will become negatively charged if you rub it against your hair, while your hair will become positively charged. Due to the attraction of opposite charges, the balloon will then adhere to your hair.

Note: 

• An electron has a negative charge of 1.6 × 10^-19 C while a proton has a positive charge of 1.6 × 10^-19 C. 
• The charge contained in 6.25 × 10¹⁸ electrons is equal to one coulomb (C), the SI unit of electric charge.

Learn more about Electric Charge

Example: Calculate the number of electrons constituting one coulomb of charge.

Solution:

We know that the charge of an electron is 1.6 × 10^-19 coulomb (or 1.6 × 10^-19 C).
Now, If charge is 1.6 × 10^-19 C, No. of electrons = 1

If charge is 1 C, then No. of electrons = 1 / (1.6 × 10^-19 C) = 6.25 × 10¹⁸ electron

Electric Current

The movement of electrons via a conductor, such as a wire, is known as electric current. Amperes (A) are units used to measure electric current. The flow of one coulomb of charge per second is equal to one ampere.

For instance, 1 coulomb of charge will flow through a wire if a current of 1 A runs through it for 1 second.

Many items in our homes and workplaces, including lights, appliances, and computers, are powered by electric current.

The magnitude I of the electric current flowing through a conductor if a charge of Q coulombs flows through it in time t seconds is given by:

The letter A stands for an ampere, the SI unit of electric current.

The electric current flowing through a conductor is stated to be 1 ampere when 1 coulomb of charge passes through any cross-section of it in 1 second.

Ammeters are devices that measure current. The circuit in which the current is to be measured and the ammeter are both permanently linked in series

Learn more about Electric Current

Example: An electric bulb draws a current of 0.25 A for 20 minutes. Calculate the amount of electric charge that flows through the circuit.

Solution:

Current, I = 0.25 A
Charge, Q = ? (To be calculated)
And Time, t = 20 minutes
⇒ t = 20 × 60 seconds
⇒ t = 1200 s

Thus, I = Q /t

⇒ Q = It

⇒ Q = 0.25(1200)

⇒ Q = 300 C

Thus, the amount of electric charge that flows through the circuit is 300 coulombs.

Electric Circuit

Electrons can be made to move by a battery, but they require a path to follow. An electrical circuit is a channel that enables electrons to move from a battery to a component, such as a light bulb.

A battery, a conductor, and a gadget are the three main components of a circuit. The battery supplies the energy necessary to move the electrons. The conductor is the channel through which electrons move. A lightbulb is an example of a device, which is something that uses energy from electrons.

Electrons will move from the battery to the device and back to the battery when all of the components of a circuit are connected. A circuit operates in this manner.

Positive and negative terminals are present on batteries. A copper wire connects the positive terminal to the positive end of a light bulb. The opposite end of the light bulb is wired to the negative terminal. In between the two terminals is a switch. A complete circuit is created and current flows through it when the switch is closed. The light bulb is lit by this current.

The circuit is broken when you flip on the switch. This indicates that the current course is no longer complete. The light bulb will stop glowing if the circuit is not complete and the current cannot flow.

Read more about Electric Circuit

Electric Circuit Symbols

Electrical circuits are represented by circuit diagrams. A circuit diagram uses corresponding electrical symbols to represent the relationships between the various electrical components in a circuit.

Electric Potential

When positioned close to a negative charge, a positive charge will feel a pull in that direction. It takes effort to separate the positive charge from the negative charge. The electric potential at a specific place indicates how much effort is needed to transport a positive charge from infinity to that position. The greater your potential, the more work you must put in.

The unit used to measure electrical potential is the volt. The labor is required to move one coulomb of charge one meter is equal to one volt.

Potential Difference

Potential difference is the term used to describe the difference in electric potential between two places. It is the effort required to transfer a unit charge from one location to another.

Alternate names for potential differences include voltage. Current in a circuit is fueled by voltage.

The potential difference V between the two points is given by the formula if W joules of work must be done to transport Q coulombs of charge from one place to the other. 

Where,

• W is the work done, and
• Q is the quantity of charge moved.

Volt, represented by the letter V, is the symbol for the potential difference in the SI system. Occasionally, the potential difference is denoted by the symbol p.d.
A device known as a voltmeter is used to measure the potential difference.

Example: How much work is done in moving a charge of 2 coulombs from a point at 118 volts to a point at 128 volts?

Solution:

Q = 2C (coulombs)

Thus, V = 128 – 118

⇒ V = 10 volts

and V = W / Q

⇒ 10 = W / 2

⇒ W = 20 joules

Thus, 20 joules of work is done in moving a charge of 2 coulombs from a point at 118 volts to a point at 128 volts.

Read more about Different between EMF and Potential Difference

NCERT Notes for Class 10 Physics Chapter 12 Electricity is important to study this chapter carefully because it forms the foundation for many other concepts that you will learn later on. Many exam questions will be based on this chapter, so it is essential to have a good understanding of the material.

Chapter 12 of the NCERT Class 10 Physics textbook explores electricity. It covers a variety of topics, including electric current, circuits, power, resistance in series and parallel, and Ohm’s Law. These notes are designed to provide students with a comprehensive summary of the entire chapter and include all of the essential topics, formulas, and concepts necessary for success on exams.