Basic Electrical Components

Passive components

cannot introduce net energy into the circuit
cannot rely on a source of power, except for what is available from the (AC) circuit they are connected to
cannot amplify (increase the power of a signal)
may increase a voltage or current

Resistor

restricts the flow of current in the circuit
absorbs the electrical energy and degenerates it in the form of heat
can vary or fixed resistances

The current flowing through a resistor is directly proportional to the voltage across the resistor terminals.
The relationship is represented by Ohm’s law.

Ohms law V=IR from this equation, we can get I=V/R
Where, ‘V’ is the Potential difference of the conductor, ‘I’ is the current through the conductor and ‘R’ is the resistance of the conductor.

Capacitor

a two terminals component
made from two conductive plates with an insulator between them
stores electrical energy
maintains the charge even after getting disconnected

They are used for filtering power supply lines, tuning resonant circuits, and for blocking DC voltages while passing AC signals, among numerous other uses.

Inductor

a two-terminal passive component
made from two conductive plates with an insulator between them
stores electrical energy in the form of magnetic energy

When a current flows through the coil from the left side to the right side – the coil produces a magnetic field in the clockwise direction

Transformer

consists of two coils of wire
changes the current and voltage levels easily
increase (step-up) or decrease(step-down) AC voltages

The transformer works on the principle of Faraday’s law of electromagnetic induction, that is, mutual inductance between two circuits, that is linked by a common magnetic flux

Fuse

a material or a piece of wire
protects components from destruction due to excessive current flowing through them

When the fuse melts due to overflow of current then, the element of the fuse absorbs some energy

Diode/LED (Light Emitting Diode)

made from semiconductor material
allows current to flow in one direction
blocks the current which tries to go against the flow in a wire
LED emits light at a particular frequency

LEDs are used in numerous applications like keyboards, hard disks, TV remote controls, often as status indicators in computers as well as battery-operated electronics Transistors

Transistors

consists of three terminals
made of semiconductor material
controls the flow of voltage or current
acts as a switch for electronic signals

In Transistors, the base terminal is responsible for activating the transistor, emitter terminal is the negative lead and collector terminal is the positive lead

Active components

rely on a source of energy (usually from the DC circuit)
usually can inject power into a circuit
includes amplifying components