Question

State ohm's law give its mathematical expression

Answer 1

so ohm's law states that the potential difference across two points is directly proportional to the amount of current flowing through the resistor given that the temperature is constant show the mathematical expression you can give is:
V is proportional to I
v is equal to I k
now k is equal to r that is resistance of the resistor
hence v is equal to IR

Answer 2

it is given by German physicist George Simon Ohm in 1827. The law states that potential difference across the ends of given metal wire in an electric circuit is directly proportional to the current flowing through it ,provided temp.  and other physical conditions remain unchanged .

mathematically ,

v $\alpha$ I

V=IR

WHERE R is proportionality constant (resistance)