Quote by Mitadru Banik
A non Ohmic relation of current and voltage is I=α(exp(eV/kT)1). Where α,K,T,e are constant. What will be the incremental resistance?
My question is if it don't follow the Ohmic equation then how it possible to find the resistance?

Incremental resistance refers to small signal resistance. This means that when you take a nonlinear load line like the one described by your equation, and vary your position along that line very small by changing the voltage or current respectively small, you will be operating along an approximate linear region, since the tangent along this curve at any point is a straight line, which will be an ohmic relation in the sense that it is linearized on this small increment.
Incremental should give you the clue to use a derivative (dV/dI) which is in units of ohms.