Objectives:
At the endof the lesson,
students should be able to:
• Define capacitance and
capacitor
• Explain how capacitors
store energy
• Differentiate series and
parallel capacitors
3.
What is aCapacitor?
• A capacitor is an electrical device
used to store electric charge.
It consists of:
- Two conducting plates
- An insulating material called
dielectric
• Capacitors temporarily store
energy in an electric field.
4.
Capacitance
• Capacitance isthe ability of a capacitor to store
charge per unit voltage.
• Formula:
C = Q / V
Unit: (F) Farad
Where:
C – capacitance (farad)
Q – charge (coulomb)
V – voltage (volt)
5.
Parallel
Plate
Capacitor
• The simplesttype of
capacitor.
Formula:
Unit: (F) Farad
Where:
• ε = permittivity of
medium
• A = plate area
• d = distance between
plates
6.
Dielectric Material
• Adielectric is an
insulating material
placed between
capacitor plates.
Functions:
- Increases capacitance
- Reduces electric field
- Prevents short circuit
7.
Capacitors
in Series
• Whencapacitors are connected
end-to-end (one path), they are
in series.
• Equivalent capacitance:
() -1
Unit: (F) Farad
Important points:
• Same charge (Q) on each
capacitor
• Equivalent capacitance is less
than any individual capacitance
8.
Capacitors
in Parallel
• Whencapacitors share both
terminals, they are in parallel.
• Equivalent capacitance:
Important:
• Voltage (V) is same across all
• Equivalent capacitance is greater
than individual capacitors
Applications
of
Capacitors
🔹 Electronic devices
(smartphones,computers)
🔹 Power supply smoothing
🔹 Timing circuits (oscillators,
clocks)
🔹 Camera flashes
🔹 Memory storage
🔹 Filters in radios and TVs
• Capacitors are everywhere in
modern electronics!
11.
Summary
• Capacitors storeelectric
charge and energy
• Capacitance depends
on geometry and
dielectric
• Series and parallel
combinations affect
capacitance
• Capacitors are essential
in electronic devices
