q define amplification factor drain resistance

Question

Q. Define amplification factor, drain resistance and transconductance and derive the relationship between drain resistance and trans conductance?

Drain resistance

It is the ratio of change in drain-source voltage (?VDS) to the change in  drain current ?ID)  at constant gate-source voltage ie ac drain resistance r_d = ΔV_DS / ΔID at constant V_GS.