4. The open-loop transfer function of a unity feedback system is G(s)H(s) = 10(0.05s + 1)/[(s + 1)(0.5s + 1(0.1s + 1)]. Determine the gain margin, phase margin, and gain crossover frequency. Comment on the stability of the closed loop system. Ans. Gain crossover frequency = 4.5 rad/sec, phase crossover frequency = 9.4 rad/sec, gain margin = 14 dB, phase margin = 45° 6. Find the transfer function of a system having the Bode plot (magnitude) shown in Figure 1. dB nu of abnom 0 = 1 0 = 10 w = 100 log o - 20DB/decade 06- -20DB/decade -401B/decade (b) A ympto low 12 /dele s+100 der junction of a unity ledb le (d) Ans. s(s+10) noitanul srdo uminim 20

Q-4. How many op-amps are required to implement this equation? V1+ R2 V. =- A) 3 B) 4 C) 2 D) 1 Q- 5. For the following feedback circuit. Identify the type of feedback and find the closed loop gain. E A ► VOUT

Linear Feedback Systems

H.w:for the circuit shown determine the feedback topology and determine Avf, Rif, Rof 1.2K v. w 3K 300 R Vo hfe=50 Circuit Diagram hie=1.1k.ohm Ans www 1.2K RE=50 Avf =9.83 Rif=23 Rof=0.5

Problem # 8 The scope sclickable &draable. More bere Each figure to the left shows two systems, an upper unity feedback gain and lower system which has an adjustable feedback gain. Both systems in each case (three cases) have a forward gain, Gain1, set always to 5 which is constant. Tme domaia plet Tme.demain.alot Sirpi Ietrgret ti Integrat 8. The feedback gain, Gain3, is varied from =8 to a value of C, which is 1.8. The upper response is in green and the pink response is for the lower system. As the feedback gain is decreased, what happens to the steady state error: T The scope is elikkatle&draggable. More here Time demain plet Intrgrat Cal Sempel A. IT INCREASES B. IT DECREASES Ca latrgrat Seepel c. IT IS THE SAME AS WE ARE NOT LOOKING AT THE STEADY STATE RESPONSE D. THESE FIGURES ARE ONLY SHOWING THE TRANSIENT RESPONSE Cala i h L N Lie Te Transfer Function Bode plot OrvOf Time Domain Scope Ovo Dewnear The scope s clickable & draatle. More here Time domain plot Call Iiegret Sepel…

Given the feedback circuit below and assuming the voltage amplifier has gain A₂, input resistance R₁ and output resistance Ro, answer the following questions: + a. Loop gain b. Closed loop gain Re C. Input resistance d. Output resistance Rin м + RE A) Sketch the feedback small signal model of this circuit. (Hint: You may convert the input VIN and source resistance Rs to its Norton current equivalent if needed) B) Find the following in terms of the amplifier parameters and resistances R, and RF: Rout

YOu are attempting question 2 out of 12 Consider the open loop transfer function of unity feedback system: K G(s) = ,t, 0.5 sec and =0.4 for dominant poles of closed %3D %3D s² +20s +101)( s+20) loop system. What is the compensator zero when pole is at -15. Answer Choices: a. z = -1 b. z = 0.0685 C. Z = 0.685 d. z=1.0685 Answer A D Submit fg fg 144 f6 4+ f5 & 7 % CO %24

For the transfer function below Is there a gain using a proportional only feedback system where the closed loop poles all lie at the same point on the complex plane ( meaning all 3 poles are the same)