Table of Contents

Hello reader I hope you all are fine we know your exam is coming and you want to quick revision of your chapter so Today i am going to tell about the topic Electricity class 10th notes chapter 12

The notes are according to your ncert book from cbse pattern so lets get started .

## Notes of chapter 12 class 10th electricity

Do You know about what is electricity ,how its can flow what is conductor and meaning of conductivity

**What is electricity** :- Electricity is define as a flow of electric current from a particular area (transforma) to another area (to your home ) its flow by an electric path also name as electric circuit ,

Electricity flow can be measure as a voltage and we can control it by putting resistance here we describe you deeply.

**Electric circuit** :- A path which can be open and closed and electric current flow from it called electric circuit

**Electric current** :- We know that all conductor have electron and this electron are carry electricity charges the flow of electric charge in a conductor name as electric current .

The direction of electric current is opposite to the flow of electric current

**How can we express** :-

From the chapter 12 electricity class 10th notes we provided you the best way

It can be measure as a amount of flowing charge through a particular area, It is denote as ” I ”

The flow of total number of charges in a conductor at a particular time is called electric current

Total time taken divided to number of flowing of charges from one point to another point give the electric current

total time = t ( per second ) , Number of charges = Q I = Q / t

Coulomb is the SI ( International system of unit ) unit of electric charge and we denote as capital ” C “

1 Coulomb equal to 6 × 10^{18} electrons

Ampere is the SI ( International system of unit ) unit of electric current and we denote as capital ” A ”

Flowing of an electric charge through a surface at the rate of 1 Coulomb per second is known as Ampere

1 Ampere is equal to 1 coulomb divided by 1 sec

1A = 1C / 1s

**Small amount of electric current** :- Small amount of electric current is write as miliampere and microampere.

miliapmere is denoted as mA and microampere is denoted as a pA

1 mA = 10^{-3} A

1 pA = 10^{-6} A

we can measure electric current from electric by a device called ammeter

**Charge**:-

**Charge** :- there are two types of charge and its a property of matter

**Negative charge and positive charge **:- Positive charge can be generate by rubbing of rod made up with glass with silk fabric

an negative charge can be generate by rubbing of rod made up with iron in wool fabric

**Like and unlike charges **:- Like charges like positive + positive and negative + negative they repel each other

Unlike charges like positive + Negative they are opposite charge and attract each other

The forces between two charges varies directly as product of two charge and inversely as the square of distance ( r ) and both charges

1 C = 1 A x 1 s

The quantity of charge which flows through a circuit when one ampere of current flows through it in one second is known as 1-coulomb charge.

**Electric potential and potential difference** :-

The amount of electric potential energy at a point is name electric potential

**Potential difference** :- The difference in the amount of potential energy between two electrical potential point in a electric circuit is called potential difference.

This difference is called voltage , It is determine as the work done to move unit charge from one point to another in a static field

Voltage = Workdone divided by charge

Voltage is denote as a capital “V” V = W / Q

The name volt is denote to the honour of an Italian Physicist name Alessandro Volta. SI unit of potential difference is Voltage

Joule is unit of work and coulomb is unit of charge so we get 1 volt is equal to 1 joule divided by 1 coulomb

joule is denote as J and coulomb is C and voltage as V so , 1 V = 1 J / 1 C

1V = 1JC^{-1}

We can measure the volt of electric current by volt meter it is device help to measure potential difference of two point

A device which detect the current in a circuit called galvanometer

#### Lets discuss about the ohms law and ressistance

**Ohms Law** :- Ohms law say that the potential difference between two is point is directly proportional to electric current at a constant temperature

we can written this as

V ∝ I

V= R I

I = V / R

R = V / I

Where R is called as resistance

**Resistance** :- It is a property of a conductor where the flow of electric current resist by a conductor through it , SI unit of resistance is ohm denote by greek letter Q

we can say that 1 ohm of resistance is equal to 1 A current flow through a conductor between the two point of potential difference is 1 V

1 ohm = 1 A / 1 V

Electric current through a resistor is inversely proportionate to the resistance which means if current decreases in a conductor then its resistivity were increase

**Resistor **;- A component used to resist the flow of current in a circuit is called resistor.

resistor is use to increase and decrease flow of electric current

**Variable** **Resistance** :- A component use to resist the flow of current without changing the voltage from the source is name as variable resistance

Rheostat is a device which is used in circuit to provide variable resistance

#### Causes of resistance in a conductor :-

Flow of current from a conductor is possible by electron present in conductor and we no that electron have a negative charge then the positive charge of particle reduce the flow of current because they attract the electrons so this attraction make a hindrance this hindrance cause the resistance in conductor they are depend in this :-

**Type of material **:- some material create less hindrance so they are good conductor of electricity hence some are create more hindrance then they are bad conductor of electricity

Bad conductor also known as insulators they can be use as protection from electric shok for example rubber gloves

**length of conductor **:- If length of conductor increase then the resistivity of conductor were also increase because of they are directly proportionate to each other

**Area of cross section **:- If area of cross section were increase of a conductor then its resistivity were decrease because of they are inversely proportionate to each other

**Resistivity** :-It is define as the resistance offer by a cube of a material of side 1m when current flows perpendicular to its opposite faces. It’s S.I. unit is ohm-meter (Ωm).

**Combination of resistance** :-

Series Combination

Parallel Combination

**Series Combination** :- The connection of resistor is straight and have a end to end connection this type of combination is called series combination ,

in this case the total resistance is equal to the sum of number of resistor in circuit

Let, three resistors R_{1}, R_{2}, and R_{3} get connect in series.

Potential difference across A and B = V

Potential difference across R_{1}, R_{2} and R_{3} = V_{1}, V_{2} and V_{3}

Current flowing through the combination = I

We, know that

V= V_{1} + V_{2} + V_{3} …. (i)

According to Ohm’s Law :

V_{1} = IR_{1}, V_{2} = IR_{2} and V_{3} = IR_{3} ….. (ii)

Let, total resistance = Rs

Then, V = IR_{s} …(iii)

From equations (i) and (ii) and (iii)

IR_{s} = IR_{1} + IR_{2} + IR_{3}

R_{s} = R_{1} + R_{2} + R_{3}

When the resistors are connected in series, the current flowing through each resistor is the same and is equal to the total current.

**Parallel Combination** :- when we join the resistors parallel in circuit the resistance is equal to the sum of reciprocal of resistance

**Heating effect of electric current** :-

In the notes of chapter 12 class 10th electricity

When electric currents supply to conductor it get heated because of energy were released in a form of heat on resistor , this happen because of dissipation of electrical energy known as heating effect of electric current example iron rod and iron heater when electricity passes through it they will be heated

**joule law of heating** :- It is states that the heat produced in a conductor is directly proportionate to the square of the current I through it and also proportionate to its resistance R and the time t taken to passed the current

**Electrical energy** :- It is the total work done in maintaining an electric current in an electric circuit for given time

Electric energy = W = VIt

**Electric power** :- Electric power is the rate at which electric energy is consume by an appliance

P = W/t = VI x I = V x V I R

**Watt** :- It is SI unit of power . The Power of an appliance is 1 watt if one ampere of current flows through it on applying a potential difference of 1 volt across its ends

Kwh :- It is the commercial unit of electrical energy. One kilowatt hour is the electric energy consumed by an appliance of 1000 watts when used for 1 hour

1 kilowatt hour = 3.6 x 1000000

So now readers we ended the chapter i hope you guys learn something from it