Electricity is the science of electrical charges and their interactions. It involves the presence and flow of electric charges like electrons. Some key points: - Electricity is caused by positive or negative charges and allows phenomena like lightning and electromagnetic waves. Charges can be positive or negative. - Conductors allow electric current to flow due to free electrons, while insulators do not. Common conductors include metals, and common insulators include glass, plastic and rubber. - Electric potential and potential difference refer to the electrical energy per unit charge. Voltage is defined as the work required to move a charge between two points, and is measured in volts. - Current is the flow of electric charge

1. ElectricityElectricity
Made By:Made By:
Manthan Somvanshi X C

2. What is Electricity ?What is Electricity ?
Electricity is the science, engineering, technology andElectricity is the science, engineering, technology and
physical phenomena associated with the presence and flowphysical phenomena associated with the presence and flow
of electric charges. Electricity gives a wide variety of well-of electric charges. Electricity gives a wide variety of well-
known electrical effects, such as lightning, static electricity,known electrical effects, such as lightning, static electricity,
electromagnetic induction and the flow of electrical currentelectromagnetic induction and the flow of electrical current
in an electrical wire. In addition, electricity permits thein an electrical wire. In addition, electricity permits the
creation and reception of electromagnetic radiation such ascreation and reception of electromagnetic radiation such as
radio waves.radio waves.

3. Electrical Charges
 What are ElectricalWhat are Electrical
ChargesCharges ??
In order to understand electricity we should first know things about electricalIn order to understand electricity we should first know things about electrical
charges.charges.
It is a property of some subatomic particles,whichIt is a property of some subatomic particles,which
determines their electromagnetic interactions. Electricallydetermines their electromagnetic interactions. Electrically
charged matter is influenced by, and produces ,charged matter is influenced by, and produces ,
electromagnetic fields. Ex- When comb is rubbed with aelectromagnetic fields. Ex- When comb is rubbed with a
dry hair ,then it gets electric charge .dry hair ,then it gets electric charge .
• Positive Charges:Positive Charges: By convention , the charge acquired by a glassBy convention , the charge acquired by a glass
rod (rubbed withrod (rubbed with
 Types of Electric Charges:Types of Electric Charges:
silk cloth) is called positive charge.silk cloth) is called positive charge.
• Negative Charges:Negative Charges: Similarly, the charge acquired by an eboniteSimilarly, the charge acquired by an ebonite
rod (rubbed withrod (rubbed with a woolen cloth) is called a negative charge.a woolen cloth) is called a negative charge.

4. Properties of ElectricProperties of Electric
Charges:Charges:
An important property of electric charge is that:An important property of electric charge is that:
 Opposite charges (or unlike charges) attract each other.Opposite charges (or unlike charges) attract each other.
Similar charges (or like charges) repel each other.Similar charges (or like charges) repel each other.
NOTE:NOTE: The SI unit of electrical charge isThe SI unit of electrical charge is Coulomb.Coulomb.
What is 1 Coulomb ?What is 1 Coulomb ?
One coulomb is that quantity of electric charge which exerts a force of 9One coulomb is that quantity of electric charge which exerts a force of 9 xx 101099
newtons on an equal charge placed at a distance 1 meter from it.newtons on an equal charge placed at a distance 1 meter from it.

5. Conductors & InsulatorsConductors & Insulators
• Those substances through which electricity can flowThose substances through which electricity can flow
are called conductors. Ex.-All the metals like silver,are called conductors. Ex.-All the metals like silver,
copper and aluminium etc. are conductors.copper and aluminium etc. are conductors.
• Those substances through which electricity cannotThose substances through which electricity cannot
flow are called insulators. Ex.- Glass , ebonite ,flow are called insulators. Ex.- Glass , ebonite ,
plastic , some rubbers etc. are insulators.plastic , some rubbers etc. are insulators.
• The presence of “free electrons” in a substance makesThe presence of “free electrons” in a substance makes
it a a conductor (of electricity.)it a a conductor (of electricity.)
ConductorConductor
InsulatorInsulator

6. Electric Potential & PotentialElectric Potential & Potential
DifferenceDifference
The electric potential ( or potential) at a point in anThe electric potential ( or potential) at a point in an
electric field iselectric field is
defined as the work done in moving a unit of positivedefined as the work done in moving a unit of positive
charge fromcharge from
infinity to that point.infinity to that point.
Electric Potential:Electric Potential:
Potential Difference:Potential Difference:
The potential difference between two points in anThe potential difference between two points in an
electric circuit is defined as the amount of work done inelectric circuit is defined as the amount of work done in
moving a unit charge from one point to another point. Itsmoving a unit charge from one point to another point. Its
formula is:formula is:

7. FORMULA OF POTENTIAL DIFFERENCEFORMULA OF POTENTIAL DIFFERENCE
Potential difference=Potential difference= Work doneWork done
Quantity of chargeQuantity of charge
movedmoved
Now, V = W/QV = W/Q
Here, W = work doneHere, W = work done
Q = quantity ofQ = quantity of
charge movedcharge moved
V= potentialV= potential
differencedifference
Note: The SI unit of potential differenceThe SI unit of potential difference
is Volt.is Volt.
Click to know further about Potential DifferenceClick to know further about Potential Difference

8. POINTS TO REMEMBER:
 Voltage is the other name for potentialVoltage is the other name for potential
difference.difference.
 The potential difference between twoThe potential difference between two
points is said to be 1 volt if 1 joule of workpoints is said to be 1 volt if 1 joule of work
is done in moving 1 coulomb of chargeis done in moving 1 coulomb of charge
from one point to another.from one point to another.
Instrument’sInstrument’s
Corner:Corner: The potential difference is
measured by means of an
instrument called
voltmeter. Its symbol is

9. Electric Current
What is an Electric Current?What is an Electric Current?
It is the potential difference between the ends ofIt is the potential difference between the ends of
wire which makes the electric charges (or current) towire which makes the electric charges (or current) to
flow in the wire.flow in the wire.Note: Amount of charge is shown by “q” or “Q” & Current isNote: Amount of charge is shown by “q” or “Q” & Current is
shown by “I”.shown by “I”. Formula:
I =I =
qqNote: SI unit of current is Ampere (A)Note: SI unit of current is Ampere (A)
What is 1 ampere ?
When 1 Coulomb of charge flows through any cross-When 1 Coulomb of charge flows through any cross-
section of a conductor in 1 second , the electric currentsection of a conductor in 1 second , the electric current
flowing through it is said to be 1ampere.flowing through it is said to be 1ampere.
I = q / t If , t = 1 secI = q / t If , t = 1 sec
Instrument’s Corner:Instrument’s Corner:
Current is measured
by an instrument
called ammeter. Its
symbol is:

10. The conventional direction of electric current is from positiveThe conventional direction of electric current is from positive
terminal of a cell (or battery) to the negative terminal , throughterminal of a cell (or battery) to the negative terminal , through
the outer circuit .the outer circuit .
Direction Of Electric Current:Direction Of Electric Current:

11. Electric Circuits & Circuit SymbolsElectric Circuits & Circuit Symbols
What is a circuit ?What is a circuit ?
A continuous conducting path consisting of wires andA continuous conducting path consisting of wires and
other resistances ( like electric bulb ,etc) and a switchother resistances ( like electric bulb ,etc) and a switch
between the two terminals of a cell or battery alongbetween the two terminals of a cell or battery along
which an electric current flows , is called a circuit.which an electric current flows , is called a circuit.

12. Circuit Symbols:Circuit Symbols:

13. Circuit Diagram
A diagram which indicatesA diagram which indicates
how different components inhow different components in
a circuit have beena circuit have been
connected by usingconnected by using
electrical symbols for theelectrical symbols for the
components is calledcomponents is called
circuit diagram.circuit diagram.

14. Ohm’s Law
At constant temperature , the current flowingAt constant temperature , the current flowing
through a conductor is directly proportional to thethrough a conductor is directly proportional to the
potential difference across its ends.potential difference across its ends.
If I is the current flowing through a conductor andIf I is the current flowing through a conductor and
V is the potential difference across its end, thenV is the potential difference across its end, then
according to Ohm’s law:according to Ohm’s law:
I ∝V (at constant temperature
or V I or V= R∝ x I Here , R=
“resistance”
We can also write :
R=V/IR=V/I Here, R=resistance , V= Potential difference and I

15. Graphical Representation of Ohm’sGraphical Representation of Ohm’s
Law:Law:
If a graph is drawn between potential
difference readings (V) and corresponding
current values (I) , the graph is found to be a
straight line.

16. Resistance:Resistance:
Resistance
The property of a conductor due to which it
opposes the flow of current through it is called resistance.
Formula:Formula:
R=V/IR=V/I
Here, R= resistance ,V= potential difference ,I=Here, R= resistance ,V= potential difference ,I=
currentcurrentFactors Affecting Resistance Of a ConductorFactors Affecting Resistance Of a Conductor
Length of a conductor.Length of a conductor.
Cross-sectional area of a conductorCross-sectional area of a conductor
Nature of material of a conductorNature of material of a conductor
TemperatureTemperature

17. Resistivity
It has been found by experiment that:It has been found by experiment that:
Resistance of a conductor :Resistance of a conductor :
RR l (length of a conductor)∝ l (length of a conductor)∝
Also, R 1/A (X-sectional area)∝Also, R 1/A (X-sectional area)∝
0r, R l/A∝0r, R l/A∝
Or R=Or R= l/aϱl/aϱ
HereHere ϱϱ is a constant for a particular material and at a certainis a constant for a particular material and at a certain
temperature.temperature.
Note :Note : Resitivity of alloys is more than theResitivity of alloys is more than the conductors or pureconductors or pure
materials.materials.

18. Thank You