# Construction of Phase-Trajectories MCQ’s

This set of Control Systems Multiple Choice Questions & Answers (MCQs) focuses on “Construction of Phase-Trajectories”.

1. The open-loop transfer function of a unity feedback system is K/(s^2 (s+5))The system is unstable for
a) K>5
b) K<5
c) K>0
d) All of the mentioned

2. Peak overshoot of step-input response of an underdamped second-order system is explicitly indicative of
a) Settling time
b) Rise time
c) Natural frequency
d) Damping ratio

3. Electrical time-constant of an armature-controlled dc servomotor is :
a) Equal to mechanical time-constant
b) Smaller than mechanical time-constant
c) Larger than mechanical time-constant
d) Not related to mechanical time-constant

4. A unity feedback system with open-loop transfer function G (s) = 4/[s(s+p)] is critically damped. The value of the parameter p is
a) 4
b) 3
c) 2
d) 1

5. In optimum time switching curve the system takes :
a) Minimum time in reaching desired location
b) Maximum time in reaching desired location
c) Never reaches
d) No desired location is present

6. Zeroes are defined as:
a) Roots of the denominator of the closed loop transfer function
b) Roots of the numerator of the closed loop transfer function
c) Both of the mentioned
d) None of the mentioned

7. Polar plot of G (jw) = 1/jw(jw+t) is
a) Crosses the negative real axis
b) Crosses the negative imaginary axis
c) Crosses the positive imaginary axis
d) None of the mentioned

8. System with logic switching are :
a) Hang on
b) Bang on
c) Bang-bang
d) Hang out

9. As zero moves sufficiently left from the origin the effect of zero becomes less pronounced.
a) True
b) False

10. Assertion (A): The zeroes on the real axis near the origin are generally avoided in design.
Reason (R): In a sluggish system introduction of zeroes can improve the transient response
a) Both A and R are true and R is correct explanation of A
b) Both A and R are true but R is not correct explanation of A
c) A is true but R is false
d) A is false but R is true