class 10 science chapter 12 notes
class 10 science chapter 12 notes
class 10 science chapter 12 notes electricity full explained in detail chapter notes, science notes electricity chapter 12 class 10 cbse, here is the collection of all topic of science chapter 12 class 10 notes, all topic are explained in full detail and easy language.
here is also present short revision notes of all chapter for class 9 and class 10 physics, chemistry and much more in easy language all student can understand.
What is charge?
Charge of two types:-
- Positive charge
- Negative charge
- Like charge repel each other and unlike charge attract each other.
- Charge is conserved in nature.
- Charge is quantiesed in nature.
- Charge is denoted by Q.
- S.I unit of charge is Coulomb.
- Charge is scalar quantity.
Electric Potential
The electric potential at a point in an electric field is defined as the work done in moving a unit charge from infinite to that point.
It is denoted by V.
Potential difference
- It is the amount of workdone to bring a unit positive charge from reference point to specific point in the electric field. without producing any acceleration.
- Electric potential is denoted by V.
- S.I unit of electric potential is volt.
Potential difference = workdone/ quantity of charge move
V = W / Q
If W = 1 Joule, and Q = 1 coulomb then V = 1 volt
Define 1 volt
- It is defined as the when 1 joule of work is done in moving a charge of 1 coulomb from reference point to specific point is called 1 volt.
Electric current
- Rate of flow of charge per unit time is called electric current.
I = Q / T
- S.I unit of current is Ampere.
- Ampere is denoted by A.
- If charge is 1 coulomb, time is 1 second then current is 1 Ampere.
- Current flowing through a conducting wire is 1 A when 1 C charge passes through conducting wire for 1 second.
Types of Current
- Direct current or DC
- Alternating Current or AC
Direct current or DC:-
- The current whose magnitude and direction does not vary with time is called direct current or Dc.
- The source of DC are Cell, Battery , and DC dianamo.
Alternating Current or AC:-
- The current whose magnitude continuously change with time and periodically change its direction is called Alternating current.
Direction of Current and Electron:-
Higher potential to lower potential. ( direction of current )
Lower potential to higher potential ( direction of electron )
Electric current:- It is the closed conducting path in which current is flow.
Voltmeter:- It is used to measure potential difference between two path.
- It has high resistance.
- It is connected in parallel combination.
Ammeter:-
- It is used to measure electric current flowing through a conductor.
- It has low resistance.
- It is connected in series.
Electric circuit
A continuous conducting path consisting of wires and other resistance like electric bulb, and a switch, between the two terminal of the battery along which an electric current flow, is called a circuit.
Ohm's law
At constant temperature and pressure ( physical condition remains same ) the current passing through the conductor is directly proportional to the potential difference across its ends.
According to Ohm's law,
According to Ohm's law,
Electric current ⋉ potential difference
I ⋉ V
From above explanation we conclude that
potential difference between two ends ⋉ current passing through the conductor
V ⋉ I
V = IR
R = V / I
where R is constant called resistance
- S.I unit of resistance is ohm Ω.
- we find that the ratio of the potential difference and the current flowing through the conductor is a constant quantity called resistance.
- the current is directly proportional to the potential difference.
- the current is inversely proportional to the resistance.
- If potential difference is double the electric current get double.
- If resistance is double then the electric current get halved.
- If potential difference is 1 V and current is 1 A then the resistance is 1 Ω.
- The conductor which obey the ohm's law are called the ohmic conductor or linear resistance.
- All metallic conductor such as silver, Aluminium, copper, Iron, etc. are the ohmic conductor.
- All conductor which do not obey the ohm's law are called the non ohmic conductor or non linear resistance.
Resistivity
it has been found by experiment that,
Resistance of a conductor is directly proportional to the length of the conductor.
R ∝ L
Resistance of a conductor is inversely proportional to the area of cross section of the conductor.
R ∝ 1/A
∴ R ∝ L/A
R = ⍴L/A
Where ⍴ ( rho ) is called the resistivity of the conductor and also known as specific resistance.
- Unit of Resistivity is ohm-m ( Ω-m ).
- Please note that resistivity of a substance does not depends on its length or thickness. It depends on the nature of the substance and temperature.
Combination of resistance
Resistance can be combine in two ways,
- In parallel combination
- In series combination
Why our house circuit is in parallel combination
If we want to increase the resistance then the combination will be in series.
If we want to decrease the resistance then the combination will be in parallel that's why in our house circuit is in parallel combination to decrease the resistance.
Resistance in series combination
The combination of multiple numbers of resistance ( multiple numbers means 2,3,4,5,6,7,8 and so on... ) in series combination is equal to the sum of the individual resistance.
for example if the resistances R1, R2, R3, R4,... etc., are connected in series then the resultant resistance will be,
R = R1 + R2 + R3 + R4 + R5 +.........etc.
Points to remember
- When a number of resistances are connected in series then the potential difference across each resistance are different.
- When a number of resistances are connected in series then the amount of electric current flowing through the each resistance are same.
Resistance in parallel combination
The reciprocal of the combined resistance of a number of resistances connected in parallel is equal to the sum of the reciprocals of the individual resistance.
for example, if the resistance R1,R2,R3,R4,R5... etc. are connected in parallel then the Resultant resistance will be,
1/R = 1/R1 + 1/R2 + 1/R3 + 1/R4 + 1/R5 + ........ etc.
Points to remember
- When a number of resistances are connected in parallel then the potential difference across each resistance is same which is equal to the voltage of the battery.
- When a number of resistances are connected in parallel then the amount of electric current flowing through the each resistance are different.
Electric power
electric power is the electrical work done per unit time.
Power = Work done/Time taken
P = W/t
Unit of power
The power of 1 watt is a rate of working of 1 joule per second.
1 watt = 1 joule/1 second