Physics 2

Voltage

-The force that pushes electricity

through a circuit

-The difference in potential energy

between two points in a circuit

-Measured in volts (V)

-Provided by batteries and

generators

Current

-The rate at which electrons flow

through a circuit

-Measured in amperes (amps) (A)

-The amount of charge that flows

through a conductor in a given time

Resistance

-The tendency of a material to

oppose the flow of electrons

through a circuit

-Measured in ohms (Ω)

-Determined by the size of wires,

resistors, and other circuit

components

Ohm’s Law

-States that the current electricity in

the circuit is directly proportional

to the voltage and inversely

proportional to its resistance.

George Simon Ohm

Person who discovered ohm’s law

DIRECT CURRENT (DC)

-Is the preferred power for electronic

devices like computers and cell phones

-Comes from batteries, solar cells, or

-AC/DC converters

Has a constant voltage

-Can flow through conductors,

semiconductors, insulators, or vacuums

-Can be used to charge batteries

ALTERNATING CURRENT (AC)

-Comes from generators or outlets

-Is the electricity produced at power

plants and sent to homes

-Has a voltage that periodically

changes from positive to negative

-Has a direction of current that

periodically changes

Capacitor

-Is a component which has the ability

or “capacity” to store energy in the

form of an electrical charge

producing a potential diference

(static voltage) acroos its plate.

Polarized Capacitors

-are capacitors that have a specific positive (+) and negative (-)

terminal, meaning they must be connected in a circuit with the

correct polarity.

Common Applications of Polarized Capacitors

Power Supply Filtering – Smoothing voltage fluctuations.

🔹 Audio Circuits – Coupling and decoupling signals.

🔹 Energy Storage – Used in backup power applications.

🔹 Timing Circuits – Part of RC (resistor-capacitor) networks.

Types of Polarized Capacitors

-Electrolytic Capacitors

-Tantalum Capacitors

-Supercapacitors (Ultracapacitors)

Electrolytic Capacitors

-Used in power supplies, audio circuits, and filtering applications.

Tantalum Capacitors

-Used in space-sensitive and high-reliability applications.

Supercapacitors

Used for energy storage and quick power delivery.

Non-polarized Capacitors

-is a type of capacitor that does not

have polarity.

Common Applications of Non-Polarized Capacitors

AC Circuits – Used in AC motors, lighting circuits, and

oscillators.

🔹 Coupling and Decoupling – Blocks DC but allows AC signals to

pass.

🔹 Signal Processing – Used in audio, radio, and RF circuits.

🔹 Resonant Circuits – Used in tuning circuits, filters, and

oscillators.

Types of Non-Polarized Capacitors

-Ceramic Capacitors

-Film Capacitors

-Mica Capacitors

-Glass Capacitors

Ceramic Capacitors

-Small size, widely used in high-frequency applications.

Film Capacitors

-Used in power electronics, motor circuits, and high-voltage applications.

Mica Capacitors

-Highly stable and precise.

Glass Capacitors

Used in military, aerospace, and high-temperature environments.