Tech Trill

Resistor is the most basic electrical and electronic component, used in
electrical and electronic circuts.It is a passive but most important element.
Applications:A Resistor find many applications in electrical and electronic
circuts.It is used as
a)an electrical load
b)a current limiting device
c)a potentioal divider
d)a biasing element
e)a filter and timer in combination with capacitor


f)a relay coil in thermal relays
g)volume,brightness and tone controller in Radio and T.V. sets Etc.
Types of Resistors:-
1)Fixed Resistrors:-Resistors designed for a particular value and whose
  value cannot be varied as and when required
Based on the method used and the method of construction, fixed Resistors are
further classified into
a)Wire wound resistors(WW Resistors)
b)Carbon composition resistors(CC Resistors)
c)Cracked carbon resistors or carbon film resistors
d)Metal oxide resistors
e)Metal film resistors.
2)Varible resistors:-Varible resistors are those whose resistance value can
  be varied continuosly or in steps.They are requried to adjust the value of
  current and voltage in electrical and electronic ciruts.
Based on the type of operation, varible resistors are further classified into
a)Continuosly varible resistors
  (i)Potentiometers and (ii)Rehostats
b)Adjustable or preset resistors
  (i)Decade resistance boxes
  (ii)Thermistors
  (iii)Varistors
3)A wire wonund resistor having one or more additional terminals along its
  length generally for voltage divider applications is called tapped
  resistors.
There are two types of tapped resistors they are
  (i)Fixed tapped
  (ii)Adjustable tapped