Question

1) Explain briefly about the differential amplifier with a neat diagram. (2Marks) ii) Consider the summing operational amplifier shown below. The resistances on the inputs are both 50 k12, and the feedback resistance is also 50 k12. If the input signal voltages are 66 mV and -85 mV, determine the output voltage, (2 Marks) R = 502 Roy - 50 kn R250 kn O V-66 m peak V-85 mV peak V. Output voltage ii) The input resistance of an inverting operational amplifier given below is 11 k2 and the feedback resistance is 400 kO. If an input voltage of 80 mV is applied, determine the gain of the amplifier and hence determine the output voltage. (2 Marks) R4 - 400k Rin-11 Vin Input voltage Vout Output voltage iv) List any two demerits of Non-Inverting Amplifier (1Mark)

Answer 1

Solution Differential Amplifin is difference elecbonic Amphefin which behneen two input voltages amplifies there thsal IX + Vout Vsat let A is the gain of Amplifica got I bout a Alkava) So Vout - А V+-V-

Given Circuit sokn sokn m> son Vini - tomu Vinz -- 85 my 4 бA 0 + Vina -Vout ОА Voltage at node A = 0 KCL at node A Vin - WA Vinz - VA + - VA-Vout sokn sokn sok Vini & Vina Vout = 11gmy ( 66-85) Vout (11) Given comit 4ook Vin - som v 1 л Vin insta Vin-VA (im VA-V. 40oka Vout VA 20 en San V. 400 il 71 A = -36.36 Vin Vout -36-36x Vin = -36-36X 80. =|-2-9V ('70 Demerits of Non-inverting Amplifu © more stages are utilized based on the requirement of acheiving desised gain Based on the respechue amplifica chosen the input and the output resistance gets Varied,