CAPACITANCE

1. DR. MAHESWARI JAIKUMAR
maheswarijaikumar2103@gmail.com

2. CAPACITANCE
• Capacitance simply means the
ability of a body to store electric
charge. A common device to do
such task is a capacitor. The SI
unit for capacitance is farad.

3. • Capacitance is the ability of a system
of electrical conductors and
insulators to store electric charge
when a potential difference exists
between the conductors.
• The symbol for capacitance is
C. Capacitance is expressed as a ratio
of the electrical charge stored to the
voltage across the conductors.

5. • The SI unit of capacitance is the
farad (symbol: F), named after the
English physicist Michael Faraday.

7. • Capacitance is the ratio of the
change in electric charge of a
system, to the corresponding
change in its electric potential.
• There are two closely related
notions of capacitance: self
capacitance and mutual
capacitance.

8. • Any object that can be electrically
charged exhibits self capacitance.
• A material with a large self
capacitance holds more electric
charge at a given voltage than one
with low capacitance.

9. • The notion of mutual capacitance is
particularly important for
understanding the operations of
the capacitor, one of the three
elementary linear electronic
components (along
with resistors and inductors).

10. • A 1 farad capacitor, when charged
with 1 coulomb of electrical charge,
has a potential difference of
1 volt between its plates. The
reciprocal of capacitance is
called elastance.

11. HOW DOES THE CAPACITANCE WORK
• A capacitor is made up of two
metallic plates. With a dielectric
material in between the plates.
• When we apply a voltage over the
two plates, an electric field is
created “a capacitor works by
storing energy electrostatically in an
electric field”

12. CREATING CAPACITANCE
• A capacitor is created out of two
metal plates and an insulating
material called a dielectric.
• The metal plates are placed very
close to each other, in parallel, but
the dielectric sits between them to
make sure they don't touch.

15. FACTORS INFLUEINCING
CAPACITANCE
• The capacitance of a capacitor is
affected by the area of the plates,
the distance between the plates,
and the ability of the dielectric to
support electrostatic forces.

16. • Larger plates provide greater
capacity to store electric charge.
Therefore, as the area of the plates
increase, capacitance increases

17. MEASUREMENT OF CAPACITANCE
• Capacitance is measured in units
called farads (abbreviated F).
• The definition of one farad is
deceptively simple. A one-
farad capacitor holds a voltage
across the plates of exactly one volt
when it's charged with exactly one
ampere per second of current.

18. • A capacitance meter is a piece
of electronic test equipment used to
measure capacitance, mainly of
discrete capacitors.
• For most purposes and in most cases
the capacitor must be disconnected
from circuit.

19. • Many DVMs (Digital Volt Meters)
have a capacitance-measuring
function.
• DVM operate by charging and
discharging the capacitor under
test with a known current and
measuring the rate of rise of the
resulting voltage; the slower the
rate of rise, the larger the
capacitance

20. FORMULA OF A CAPACITOR
• The generalised equation for
the capacitance of a parallel
plate capacitor is given as:
• C = ε(A/d) where ε represents the
absolute permittivity of the
dielectric material being used.

21. USE OF CAPACITOR
• A capacitor can store electric energy
when it is connected to its charging
circuit.
• When it is disconnected from its
charging circuit, it can dissipate that
stored energy, so it can be used like a
temporary battery. In car audio
systems, large capacitors store energy
for the amplifier to use on demand.

22. TYPES OF CAPACITOR
• Film capacitors
• Paper capacitor
• Aluminum electrolytic capacitors
• Tantalum electrolytic capacitors

23. IMPORTANCE OF CAPACITOR
• Capacitors have
many important applications.
• They are used, for example, in digital
circuits so that information stored in
large computer memories is not lost
during a momentary electric power
failure; the electric energy stored in
such capacitors maintains the
information during the temporary loss
of power.

24. THANK YOU