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Step 11.006E Refer to the Figure 11 8 (c) in the text From the circuit, RD The output voltage of the amplifier is, (1) The feedback voltage is: Step (a) Find the expression for The feedback factor is, = (From equation(1) and (2)) R1 Hence, the required expression is Step (b) Find the expression for the loop gain AB. The loop gain of the amplifier is, V, Hence, the required expression is, Step (c) Find an expression for the open-loop gain A. The open loop gain A is, A = = Hence, the required expression for A is Step (d) (i) Calculate the value of 20 20+80 =0.2 Hence, the required value of is 0.2 Step (ii) Calculate the value of AB. 10x20 =4 10+20+80 800 110 =7.27 Hence, the required value of AB 7.27 Step (iii) Calculate the value of A. A=g. 10(20+80) =4 = 10+20+80 4000 110 Hence, the required value of A is 36.36 Step (iv) Calculate the value of A, 4x10 = 20 1+4x10 20+80 40 (100+800)/100 4000 900 =4.4 V/V Hence, the required value of A is 4.4 V/V Step (v) Consider the following from the part (ii) and part (iii) calculations AB 7.27 Hence, the V/V much greater than the unity.