Deck 2: Stability and Realization of Linear Systems With Feedback and Sampling

Question 1

Difference equation model results in:

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

Answer 1

both a and b

Question 2

For relative stability of the system which of the following is sufficient?

A)gain margin
B)phase margin
C)both a and b
D)magnitude

Answer 2

both a and b

Question 3

Stability of a system implies that :

A)small changes in the system input does not result in large change in system output
B)small changes in the system parameters does not result in large change in system output
C)small changes in the initial conditions does not result in large change in system output
D)small changes in the initial conditions result in large change in system output

Answer 3

small changes in the system input does not result in large change in system output

Question 4

Linear mathematical model applies to :

A)linear systems
B)stable systems
C)unstable systems
D)all of the mentioned

Question 5

With feedback _____ reduces.

A)system stability
B)system gain
C)system stability and gain
D)damping

Question 6

Asymptotic stability is concerned with:

A)a system under influence of input
B)a system not under influence of input
C)a system under influence of output
D)a system not under influence of ou

Question 7

A linear time invariant system is stable if :

A)system in excited by the bounded input, the output is also bounded
B)in the absence of input output tends zero
C)both a and b
D)system in excited by the bounded input, the output is not bounded

Question 8

If a system is given unbounded input then the system is:

A)stable
B)unstable
C)not defined
D)linear

Question 9

If the impulse response in absolutely integrable then the system is :

A)absolutely stable
B)unstable
C)linear
D)stable

Question 10

If root of the characteristic equation has positive real part the system is :

A)stable
B)unstable
C)marginally stable
D)linear

Question 11

The use of sampled data control system are:

A)for using analog components as the part of the control loop
B)for time division of control components
C)whenever a transmission channel forms a part of closed loop
D)none of the mentioned

Question 12

Jury's test determines whether the roots of a polynomial lie:

A)close to unit circle
B)within the unit circle
C)outside the unit circle
D)on the unit circle

Question 13

The transformation technique in which there is one to one mapping from s-domain to z-domain is

A)approximation of derivatives
B)impulse invariance method
C)bilinear transformation method
D)backward difference for the derivative

Question 14

Parallel form of realisation is done in

A)high speed filtering applications
B)low speed filtering applications
C)both a and b
D)none of the above

Question 15

In cascade form of realization, how many bits should be used to represent the FIR filter coefficients in order to avoid the quantization effect on filter coefficients?

A)5 to 10
B)12 to 14
C)20 to 24
D)28 to 40

Question 16

How is the sampling rate conversion achieved by factor I/D?

A)by increase in the sampling rate with (i)
B)by filtering the sequence to remove unwanted images of spectra of original signal
C)by decimation of filtered signal with factor d
D)all of above

Question 17

In the cascaded form of realisation, the polynomials are factored into

A)product of 1st-order and 2nd-order polynomials
B)product of 2nd-order and 3rd-order polynomials
C)sum of 1st-order and 2nd-order polynomials
D)sum of 2nd-order and 3rd-order polynomials

Question 18

Open loop transfer function of a system having one zero with a positive real value is called.

A)zero phase function
B)negative phase function
C)positive phase function
D)non-minimum phase function

Question 19

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

Question 20

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

Question 21

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

Question 22

State model representation is possible using _________

A)physical variables
B)phase variables
C)canonical state variables
D)all of the above

Question 23

Conventional control theory is applicable to ______ systems

A)siso
B)mimo
C)time varying
D)non-linear

Question 24

The transfer function for the state representation of the continuous time LTI system: dq(t)/dt=Aq(t)+Bx(t) Y(t)=Cq(t)+Dx(t) is given by

A)c(si-a)^-1b+d
B)b(si-a)^-1b+d
C)c(si-a)^-1b+a
D)d(si-a)^-1b+c

Question 25

The system which works on the initial condition without any input applied to it is called as :

A)homogeneous system
B)non homogeneous system
C)linear system
D)non linear system