ohm's law is V is directly proportional to I this law fails when:

1) V ceases to be proportional to I

2) The relation between V and I depends on the sign of V. In

other words, if I is the current for a certain V, then reversing

the direction of V keeping its magnitude fixed, does not

produce a current of the same magnitude as I in the opposite direction. Eg- diode

3) The relation between V and I is not unique, i.e., there is more than one value of  V for the same current I. A material exhibiting such material is GaAs

For more in depths look at page no.101 NCERT Physics Part-1

hello dear

the limitation os ohms law is::

1.Ohm's law does not work in case of non ohmic conductors like diodes,electrolytes,filaments

2.it doesnt hold at extreme temperatures

3.V is proportional to I provided temperature remains constant...