After the electricity was discovered scientist were well known about the fact that , electric energy is tranfered between two point in the form of electric current.So the whole scenario was like there are two points A and B , a simple wire is joining these two points , and suppose R is the resitance of this simple wire , and once we connect these two wires with a voltage source ( which is definitely the source of electric energy ) then an Electric current I suddenly starts flowing between the two points A and B..Refer this figure for a better analogy
So scientist were not so mad ( definitely they were not ) . Hence they started changing the value of R ( which is the resistance of wire ) , and they saw that when the value of R is increased then the amount of current flowing through the wire AB started decreasing.Now this is somewhat an interesting phenomenon that they have noticed on that time.
So Mr. Ohm came up with his own theory ( in fact he had started this experiment , arranging a simple wire between two points and varrying the resistance keeping Voltage constant )
# He noiticed that , when V is kept constant , then Increasing Resitance decreases the current in the network.
# He kept Resistance constant , and he noticed that Increasing the voltage increases the current in the network
( obviously current will be increased because voltage is nothing just a bag of electric energy and current is nothing just a carrier of this energy so once you started increasing the size of bag and the amoung of energy into it , current will atomatically increase )
So according to his experiment , he discovered a law , which says ...
Current in as circuit , I is directly proportion to the Voltage , and Inversely proportion to R
So he wrote => V = I * R or I = V / R
P.S : Jitani kahani abhi tak banayi sab samjhane ke liye thi ,
point is simple ..Ohm's law says that Voltage in the network is directly proportional to the current and when you remove the proportionality symbol , a constant factor will be multiplied and that is R .