Control Systems - Online Test
Q1. For the system 2/(s+1), the approximate time taken for a step response to reach 98% of its final value is
Answer : Option C
Explaination / Solution:
No Explaination.
Q2. The frequency response of G(s) = 1/[s(s + 1)(s + 2)] plotted in the complex G(jω) plane (for 0 < ω < ∞) is
Answer : Option A
Explaination / Solution:
No Explaination.
Q3. The characteristic equation of a closed-loop system is
s(s + 1)(s + 3) + k(s + 2) = 0, k > 0. Which of the following statements is true?
Answer : Option C
Explaination / Solution:
No Explaination.
Q4. The measurement system shown figure uses three sub-system in cascade whose gains are
specified as G1, G2 and 1/G3. The relative small errors associated with each respective
subsystem G1, G2 and G3 are ε1 + ε2 and ε3. The error associated with the output is
Answer : Option C
Explaination / Solution:
No Explaination.
Q5. The polar plot of an open loop stable system is shown below. The closed loop system is
Answer : Option D
Explaination / Solution:
No Explaination.
Q6. The first two rows of Routh's tabulation of a third order equation are as follows.
s3 2 4
s2 4 4.
This means there are
Answer : Option D
Explaination / Solution:
No Explaination.
Q7. 
The asymptotic approximation of the log-magnitude vs frequency plot of a system containing only real poles and zeros is shown. Its transfer function is
Answer : Option B
Explaination / Solution:
Q8. The unit-step response of a unity feedback system with open loop transfer function G(s) 
is shown in the figure. The value of K is
is shown in the figure. The value of K is
Answer : Option D
Explaination / Solution:
No Explaination.
Q9. The open loop transfer function of a unity feedback system is given by 
The gain margin of this system is
The gain margin of this system is
Answer : Option D
Explaination / Solution:
Q10. If the closed-loop transfer function of a control system is given as 
then It is
then It is
Answer : Option D
Explaination / Solution:
In a minimum phase system, all the poles as well as zeros are on the left half of the s −plane. In given system as there is right half zero (s = 5), the system is a non-minimum phase system.
