# Time Response of First Order Systems MCQ’s

This set of Control Systems Multiple Choice Questions & Answers (MCQs) focuses on “Time Response of First Order Systems”.

1. A unit step is applied at t=0 to a first order system without time delay. The response has the value of 1.264 units at t=10 mins, and 2 units at steady state. The transfer function of the system is_____________
a) 3/(1+600s)
b) 2/(1+500s)
c) 5/(1+220s)
d) 2/(1+600s)

2. The transfer function of the system is G(s) =100/(s+1) (s+100). For a unit step input to the system the approximate settling time for 2% criterion is:
a) 100 sec
b) 4 sec
c) 1 sec
d) 0.01 sec

3. First order system is defined as :
a) Number of poles at origin
b) Order of the differential equation
c) Total number of poles of equation
d) Total number of poles and order of equation

4. If a first order system and its time response to a unit step are as shown below, the gain K is :

a) 0.25
b) 0.8
c) 1
d) 4

5. Assertion (A): It is observed that step function is first derivative of a ramp function and impulse function is first derivative of a step function.
Reason (R): From the derived time response expression it is concluded that the output time response also follows the same sequence as that of input functions.
a) Both A and R are true and R is the correct explanation of A
b) Both A and R are true but R is not correct explanation of A
c) Both A is True but R is false
d) Both A is False but R is true

6. A system with transfer function 1/Ts+1, subjected to a step input takes to seconds to reach 50% of step height. The value of t is :
a) 6.9s
b) 10s
c) 14.4s
d) 20s

7. The unit impulse response of a system having transfer function K/(s+a) is shown below. The value of a is :

a) t1
b) t2
c) 1/t1
d) 1/t2

8.A first order system and its response to a unit step input are shown in figure below. The system parameters are____________
a) a=5 and k=12
b) a=10 and k=5
c) a=5 and k=10
d) a=8 and k=9

9. Laplace transform of unit impulse signal is :
a) A/s
b) A
c) 1
d) 1/s

10. Time response during steady state the output velocity matches with the input velocity but lags behind the input by T.
a) True
b) False