Electrical Engineering MCQ Question Papers: Campus Placement

Subject: Control System 7

**Part 1: List for questions and answers of Control System II**

** **

**Q1. A first order system is initially at and subjected to a sudden input at t=0. Its output ****reaches 1.1 V in 4 sec and eventually reaches steady state of 2 V. Find the time constant?**

**a) 4 sec**

**b) 5 sec**

**c) 2 sec**

**d) 6 sec**

** **

**Q2. A second order control system has a transfer function 16/(s² + 4s + 16). What is the time ****for the first overshoot?**

**a) 2p/v3 sec**

**b) p/v3 sec**

**c) p/2v3 sec**

**d) p/4v3 sec**

** **

**Q3. Two identical first order systems have been cascaded non interactively. The unit step ****response of the systems will be**

**a) Over damped**

**b) Under damped**

**c) Critical damped**

**d) Un damped**

** **

**Q4. A second order control system has a transfer function 16/(s² + 4s + 16). Find the settling ****time for 2% tolerance?**

**a) 10 sec**

**b) 5 sec**

**c) 4 sec**

**d) 2 sec**

** **

**Q5. Settling time for 5% tolerance band is ———-**

**a) 3T**

**b) 4T**

**c) 5T**

**d) 2T**

** **

**Q6. The optimum values of damping ration is ————–**

**a) 0.9 to 1.1**

**b) 0.3 to 5**

**c) 0.3 to 0.7**

**d) to 2 **

** **

**Q7. For the polynomial P(s) = 2s^5 + s^4 + 4s^3 + 2s^2 + 3s + 15, number of roots which lie in the ****right half of s-plane is**

**a) 4**

**b) 2**

**c) 3**

**d) 1**

** **

**Q8. For the polynomial P(s) = s^4 + 8s^3 + 18s^² + 16s +5, find the number of roots which lie on ****the right half of s-plane?**

**a) 1**

**b) 2**

**c) 4**

**d) 0**

** **

**Q9. The system having characteristic equation s^4 + 2s^3 + 3s² + 2s + k = 0 is used to be an ****oscillator. What is the value of k?**

**a) 1**

**b) 2**

**c) 3**

**d) 4**

** **

**Q10. unit step response of the system is 1 – e-t(1+t). Which is the system?**

**a) Unstable**

**b) Stable**

**c) Oscillatory**

**d) Critically stable**

** **

**Q11. The angle condition is used for checking whether any point lies on root locus or not ****is………**

**a) ± (2q + 1) 180°**

**b) ± (2q) 180°**

**c) ± (2q + 1) 360°**

**d) ± (2q) 360°**

** **

**Q12. The magnitude condition for root locus is ………………**

**a) |G(s)H(s)| = 0**

**b) |G(s)H(s)| = 2**

**c) |G(s)H(s)| = 1**

**d) |G(s)H(s)| = 8 **

** **

**Q13. A unity feedback control system has an open loop transfer function G(s) = k/(s(s² + 7s + ****12) The gain k for which s = -1 + j1 will lie on the root locus of the system is**

**a) 4**

**b) 6.5**

**c) 5**

**d) 10**

** **

**Q14. Let P = Number of open loop poles and Z = Number of open loop zeros and P>Z, find ****the number of branches terminating at 8 ?**

**a) Z**

**b) P-Z**

**c) P**

**d) any of the above**

** **

**Q15. The characteristic equation of a control system is give by s(s + 4)(s² + 2s + 1) + k(s + 1) ****=0 What are the angles of asymptotes for the root loci for k = 0?**

**a) 0°, 120°, 240°**

**b) 0°, 180°, 300°**

**c) 60°, 180°, 300°**

**d) 120°, 180°, 240°**

** **

**Q16. The characteristic equation of a control system is give by s(s + 4)(s² + 2s + 1) + k(s + 1) ****=0. Find the angle between the asymptotes?**

**a) 60°**

**b) 360°**

**c) 120°**

**d) 180°**

** **

**Q17. Which of the following statements is/are true?**

**a) Centroid may be a part of root locus**

**b) Centroid may not be a part of root locus**

**c) Both 1 and 2**

**d) Nether 1 nor 2**

** **

**Q18. The characteristic equation of a feedback control system is given by s³ + 5s² + (k + 6)s + ****k = 0. In the root loci diagram, the asymptotes of the root loci for large ‘k’ meet at a point in ****the s-plane whose coordinates are**

**a) (2,0)**

**b) (-2,0)**

**c) (-1,0)**

**d) (1,0) **

** **

**Q19. A control system has open loop transfer function G(S) = k/(s(s+4)(s+6)). Break away ****point is lies between**

**a) 0 and -4**

**b) 0 and 4**

**c) -4 and -6**

**d) any of the above**

** **

**Q20. A control system has open loop transfer function G(s) = k/(s(s + 2). Find the break away ****point?**

**a) -1**

**b) 1**

**c) -2**

**d) 2 **

** **

**Part 1: List for questions and answers of Control System II**

** **

**Q1. Answer: b**

** **

**Q2. Answer: c**

** **

**Q3. Answer: c**

** **

**Q4. Answer: d**

** **

**Q5. Answer: a**

** **

**Q6. Answer: c**

** **

**Q7. Answer: b**

** **

**Q8. Answer: d**

** **

**Q9. Answer: b**

** **

**Q10. Answer: b**

** **

**Q11. Answer: a**

** **

**Q12. Answer: c**

** **

**Q13. Answer: d**

** **

**Q14. Answer: b**

** **

**Q15. Answer: c**

** **

**Q16. Answer: c**

** **

**Q17. Answer: c**

** **

**Q18. Answer: b**

** **

**Q19. Answer: a**

** **

**Q20. Answer: a**