# State Variables and Linear Discrete-Time Systems MCQ’s

This set of Control Systems Multiple Choice Questions & Answers (MCQs) focuses on “State Variables and Linear Discrete-Time Systems”.

1. Consider the function F (s)= 5/s(s^{2}+3s+2), the initial value of f(t) is:

a) 5

b) 5/2

c) 5/3

d) 0

2. An electric motor is developing 10KW at a speed of 900rpm. The torque available at the shaft is:

a) 106 N-m

b) 66 N-m

c) 1600 N-m

d) 90 N-m

3. Which of the following can be used as a tacho generator in control systems?

a) Microsyn

b) DC servomotor

c) AC servomotor

d) Magnetic Amplifier

4. Assertion (A): Many of the linear control system transfer function do not have poles or zeroes in the right half s-plane.

Reason (R): These are called minimum phase transfer function.

a) Both A and R are true and R is correct explanation of A

b) Both A and R are true and R is not correct Explanation of A

c) A is True and R is false

d) A is False and R is true

5. The closed loop transfer function of a unity negative feedback system is 100/(s^{2}+8s+100). Its open loop transfer function is:

a) 100/s+8

b) 1/s^{2}+8s

c) 100/s^{2}-8s

d) 100/s^{2}+8s

6. In a closed loop for which the output is the speed of the motor, the output rate control can be used to:

a) Limit the speed of the motor

b) Limit the torque output of the motor

c) Reduce the damping of the system

d) Limit the acceleration of the motor

7. The tacho meter has sensitivity of 5V/1000rpm. The gain constant of the tacho meter is:

a) 0.48V/rad/sec

b) 0.048V/rad/sec

c) 4.8V/rad/sec

d) 48V/rad/sec

8. The impulse response of a linear LTI system is given as g (t) = e^{(-t)}The transfer function of the system is equal to:

a) 1/s

b) 1/s(s+1)

c) 1/(s+1)

d) s/(s+1)

9. In servo-system, the device used for derivative feedback is known as:

a) Synchro

b) Servomotor

c) Potentiometer

d) Tacho generator

10. The transfer function of any stable system which has no zeros or poles in the right half of the s-plane is said to be:

a) Minimum phase transfer function

b) Non-minimum phase transfer function

c) Minimum phase frequency response function

d) Minimum gain transfer function