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Step 1 of 8 8.052P Consider the expression the input resistance 1+g.r. Substitute 1+40 40k 41 Therefore, the value resistance Step 2 of 8 Draw the small signal equivalent circuit diagram + - 1 1 Figure 1 Step 3 of 8 analysis terminal Substitute the expression for the voltage Step Apply nodal analysis R, Substitute Here, the term represents the input resistance (1) the expression for the current gain is Step of 8 Recall equation (1) Substitute for R, and =0.954 A/A the value current gain is 0.954 A/A Step Recall equation Substitute Substitute R, and - 20k 1+40 20k - 20k =0.789 A/A Therefore, the value current when the load resistance increased by 10 times is 0.789 A/A Step Calculate the percentage change the value current 0.954-0.789 100 0.954 0.165 0.954 =0.173x100 =17.3% Therefore, the percentage change the value of the current gain 17.3% Step The circuit which transform the current source with medium source resistance to an equal current with high source called current Here the Common Gate amplifier well behaved as a current buffer having gain of 0.954 A/A which is nearly equal