Basic Electronics

                                                Resistors :

   Resistance (R) is the physical property of an element that reduce the flow of current . The unit of resistance is Ohm (Ω).

   Resistors provide a specific amount of resistance to a path in a circuit or wire.

   Resistivity (ρ) is the ability of a material to resist current flow. The unit of resistivity is Ohm-meter  (Ω-m)

    Ohm's Law:

           V = IR

I = Current measured in Amps

V = Voltage measured in Volts

R = Resistance measured in Ohms

Resistors can be either fixed or variable in value

Fixed resistors come in a variety of different shapes, sizes and forms

Axial lead resistors have the value of resistance printed on them or as a colour code

Surface mount resistors have a numerical code indicating a value.

Variable resistors are called potentiometers

There is a fixed value of resistance between two terminals

                    Fixed Resistor-Surface Mount

                       Fixed Resistor- Axial

     Variable Resistors

Variable Resistors

Capacitors

   A capacitor consists of a pair of conductors separated by a dielectric (insulator).

                                     (ε indicates how penetrable a susbtance is to an electric field)

 Electric charge is stored in the plates – a capacitor can become “charged”.

 When a voltage exists across the conductors, it provides the energy to move the charge from the positive plate to the other plate.

  

 Capacitance (C) is the ability of a material to store charge in the form of separated charge or an electric field. It is the ratio of charge stored to voltage difference between two plates.

Capacitance is measured in Farads (F)

                                      Inductors

  An inductor is a two terminal element consisting of a winding of N turns capable of storing energy in the form of a magnetic field.

  Inductance (L) is a measure of the ability of a device to store energy in the form of a magnetic field.

  It is measured in Henries (H)