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