RESISTANCE :-

RESISTANCE :-

It is the basic element of electrical and electronics instruments and machines .
Resistance can be define as a barrier in the way / path of current
in conductor (It is a single straight wire.).
We have a formula for finding the value of resistance , it is given
by scientist OHM . that is :-

V = IR                                                                                     R = V/I

It is Ohm`s law
where R = resistance of the conductor.
  V = voltage of the terminals of the conductor.
  I = current flowing in the conductor.

We can say that the ratio between voltage and current is define as resistance.

DIAGRAMS AND SYMBOLS OF RESISTANCE :-

Symbol of resistance are shown in fig. below;
We can use the symbol of resistance at the time of
circuit draw in paper.

  

SYMBOL

                                     

UNIT OF RESISTANCE :- 

Here the unit of resistance is OHM , is symbolic representation is
Greek word (omega) Ω

Where ohm = volt / ampere ;

USES OF RESISTANCE :-

Basically we use resistance to reduce current in some electronics
device.
1.) To protect device.
2.) Safety purpose.
3.) To reduce voltage.

VARIABLE RESISTANCE :-

this is A kind of resistance, but it can increase or decrease its
resistance.
is symbol and fig. shown below.

SYMBOL