Resistors

The property of a conductor which opposes the flow of current is Resistor.It control the amount of current the runs through them.on resistor body 5 band of colours are printed. units are ohms.

The circuit symbol is-

*Features of resistors:

1.These are two terminal,passive bilateral elements.
2.The effect of resistance is same for both AC and DC.

* Common uses of Resistors:

1.to limit the current.
2.to establish proper values of circuit voltages due to IR drops.
3.to provide load. etc

*Types of resistors

                                                                 resistors                                                                                                    
                         1.fixed                                                                   2.variable

      a.carbon   i.carbon composition(solid type)             a,general purpose        i. Potentiometers (Pots)
                      ii.carbon film(film type)                                                              ii.rheostats
      b.precision                                                                b.precision type           i.LDRs
                      i.wire wound                                                                                ii.Thermistors
                     ii.metal film                                                                                  iii.Varistors
      c.wire wound(power type)                                                                           iv.Trimmers

*specifications of resistors:

1.resistance value
2.tolerance
3.power rating
4.temperature coefficient of resistance
5.voltage coefficient
6.high frequency performance
7.noise figure
8.stability
9.size,shape and leads.

*resistor colour coding:

Ex: brown ,black ,red, gold
         1            0   100   5%
       
            10*100=1k