OHM'S Law

“Ohm’s law states that in a closed circuit the current is directed proportional to voltage and inversely proportional to the resistance.  When temperature is constant”

It is expressed in the form of an equation as :

   I α V     ……………. (i)

   I α I/R …………….. (ii)

Where V = Voltage in Volts

              I = Current in Amperes

              R = Resistance in ohms

From Equation (i) & (ii) we have

I α V/R     or I = V/R

From the above equation, if any two quantities are know , the third can be found :

I = V/R

V = IR

R = V/I

Example:

What will be the current passing through a resistance of 100 Ω if the supply is 200 volts.

Solution:

Supply voltage (V) = 200 V

Resistance (R) = 1000 Ω

Then Current (I) = ?

As per Ohm’s law, we know:-

I = V/R

  = 200/100

 = 2 A     (Ans.)