Deck 1: Control Systems, Sampling, and Transform Techniques

Question 1

A control system working under unknown random action is called

A)computer control system
B)digital data system
C)stochastic control system
D)adaptive control system

Answer 1

stochastic control system

Question 2

The first order control system, which is is well designed, has a

A)small bandwidth
B)negative time constant
C)large negative transfer function pole
D)none of the above

Answer 2

large negative transfer function pole

Question 3

Zero-order hold used in practical reconstruction of continuous-time signals is mathematically represented as a weighted-sum of rectangular pulses shifted by:

A)any multiples of the sampling interval
B)integer multiples of the sampling interval
C)one sampling interval
D)1 second intervals

Answer 3

integer multiples of the sampling interval

Question 4

Sampling can be done by:

A)impulse train sampling
B)natural sampling
C)flat-top sampling
D)all of the mentioned

Question 5

The first step required to convert analog signal to digital is :

A)sampling
B)holding
C)reconstruction
D)quantization

Question 6

Sampling is necessary :

A)in complex control systems
B)where high accuracy is required
C)non automated control systems
D)automated control system

Question 7

_______________ is a sampling pattern which is repeated periodically

A)single order sampling
B)multi order sampling
C)zero order sampling
D)unordered sampling

Question 8

Aliasing is caused when:

A)sampling frequency must be equal to the message signal
B)sampling frequency must be greater to the message signal
C)sampling frequency must be less to the message signal
D)sampling frequency must be greater than or equal to the message signal

Question 9

The signal is reconstructed back with the help of

A)zero order hold circuits
B)extrapolations
C)signal is reconstructed with zero order holds and extrapolations
D)signal is not reconstructed

Question 10

A control system working under unknown random actions is called ---

A)computer control system
B)digital data system
C)stochastic control system
D)adaptive control system

Question 11

Zero initial condition for a system means

A)input reference signal is zero
B)zero stored energy
C)no initial movement of moving parts
D)system is at rest and no energy is stored in any of its components

Question 12

The first order control system ,which is well designed has a

A)small bandwidth
B)negative time constant
C)large negative transfer function pole
D)none of the above

Question 13

A zero order hold is used with sampled data system to

A)make it critically damped
B)reconstruct the sampled signal
C)improve the stability of the system
D)convert it to a continuous system

Question 14

A controller is basically a ---

A)sensor
B)comparator
C)amplifier
D)clipper

Question 15

Z and Laplace transform are related by:

A)s = ln z
B)s =ln z/t
C)s =z
D)s= t/ln z

Question 16

What is the z-transform of the signal x[n] = an u(n)?

A)x(z) =1/z-1
B)x(z) = 1/1-z
C)x(z) = z/z-a
D)x(z) = 1/z-a

Question 17

Which one of the following rules determine the mapping of s-plane to z-plane?

A)right side of the s-plane maps into outside of the unit circle in z-plane
B)left half of s-plane maps into inside of the unit circle
C)imaginary axis in s-plane maps into the circumference of the unit circle
D)all of the mentioned

Question 18

Assertion (A): The z-transform of the output of the sampler is given by the series. Reason (R): The relationship is the result of the application of z = e-sT, where T stands for the time gap between the samples.

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

Question 19

Inverse z-transform of the system can be calculated using:

A)partial fraction method
B)long division method
C)basic formula of the z-transform
D)all of the mentioned

Question 20

If the z transform of x(n) is X(z) =z(8z-7)/4z2 -7z+3, then the final value theorem is :

A)1
B)2
C) ?
D)0

Question 21

Difference equation model results in:

A)sampled-data systems
B)numerical analysis of continuous time systems
C)continuous time feedback systems
D)both a & b

Question 22

Which of the following is an advantage of Laplace transform method

A)it gives solution in frequency domain only
B)it gives total solution more systematically
C)initial conditions are incorporated in the very first step
D)both b & c

Question 23

Analysis of control system by Laplace transform technique is not possible for

A)discrete time systems
B)linear systems
C)time invarient systems
D)unstable continuous time systems

Question 24

Z-transform is used in:

A)continuous optimal control problem
B)discrete optimal problem
C)control systems
D)none of the mentione

Question 25

Unit step response of the system described by the equation y(n) +y(n-1) =x(n) is:

A)z²/(z+1)(z-1)
B)z/(z+1)(z-1)
C)z+1/z-1
D)z(z-1)/z+1