Class 10 electricity notes

Class 10 electricity notes

Cbse Class 10 electricity notes

Class 10 Physics Chapter 3 Notes pdf 

Introduction

The concept of electricity came into notice due to friction. It actually proves that charges can be produced and they can also be made to flow and flowing of charges gives rise to electricity. So let us first learn about friction

Friction

It comes into notice when two bodies are rubbed with each other.

For example: Rubbing of a glass rod with silk. When a glass rod is rubbed with silk, electrons move from glass rod to silk therefore, the glass rod acquires a positive charge as it becomes deficient of electrons and silk will acquire negative charge as the amount of negative charge in it increases.

So, due to this concept of friction, the concept of charges came in to notice. And further, coulomb was the one who gave more information about the charges.

Electric charge

So it was concluded that we have two types of charges:

Positive charge

Negative charge

The symbol used for it is (q) and unit that is used to measure it is Coulomb which is denoted by C (unit).

Different experiments proved that “same charges repel each other and opposite charges attract each other.”

And also, when the electric charges are kept, they create a small area around itself where its effect can be felt called as the electric field.

The electric charge is equal to the number of electrons in it and the magnitude of charge on the electron i.e.

q = ne

where n = number of electrons and

e = charge of electron

= 1.6 x 10-19 C

Coulomb’s law

There is always some force between two charges which is directly proportional to the product of magnitude of their charges & inversely proportional to the square of the distance between them.

Types of substances depending upon their ability to conduct current

We have different kinds of substances depending upon their power to conduct electricity. They are classified as:

Conductors –They are those which allow current to pass through them. They have free mobile electrons.

For example Cu, Al, etc. Like in the given figure, the wire conducts electricity but the plastic insulation is an insulator.

Insulators-They are those which do not allow current to pass through them as they do not have free mobile electrons.

For example glass etc. Those substances which give free electrons are good conductors and those which don’t have free electrons are poor conductors.

Types of electricity

Static electricity

Current electricity

Static Electricity: Static electricity is a type of electricity when electric charges develop but do not flow.

For example charges developed by glass rod are rubbed with silk.

Current Electricity:Current electricity is a type of electricity when the electronic charges that develop are also in motion.Electrostatic potential

It is the work done in moving the positive charge from infinity to a certain point in an electric field of other charge.

For example – A unit of positive charge is at a point at infinity and we try to bring it to point b that is in the electric field of some other charge, let’s say charge q2. So the work that we need to do in doing so is called electrostatic potential.

Potential difference

When we need to move the charge between two specified points, then the work done in doing so is called the potential difference. So it is defined as the work done in moving a charge from one point to

Potential difference is said to be 1 volt when 1J of work is done in moving IC of charge from one point to another. The instrument that is used to measure its magnitude is called Voltmeter.

There is an important feature that how we connect it. It is connected in parallel because it has a high resistance and also in parallel the potential difference remains constant.