Response to the following problem:
One approach to "offset correction" involves the adjustment of the values of RC1 and RC2 so as to reduce the differential output voltage to zero when both input terminals are grounded. This offset-nulling process can be accomplished by utilizing a potentiometer in the collector circuit, as shown in Figure. We wish to find the potentiometer setting, represented by the fraction x of its value connected in series with RC1, that is required for nulling the output offset voltage that results from:
(a) RC1 being 4% higher than nominal and RC2 4% lower than nominal
(b) Q1:having an area 5% larger than nominal, while Q2:has area 5% smaller than nominal.
