Bissoy
Login
Get Advice on Live Video Call
Earn $ Cash $ with
consultations on Bissoy App
For a stable system having two or more gain crossover frequencies the phase margin is measured at the highest crossover frequency.
A
True
B
False
Correct Answer:
True
Seven people A, B, C, D, E, F and G live on separate floors of a 7-floor building. Ground floor is numbered 1, first floor is numbered. 2 and so on until the topmost floor is numbered 7. Each one of these having a different cars-Cadillac, Ambassador, Fiat, Maruti, Mercedes, Bedford and Fargo but not necessarily in the same order. Only three people live above the floor on which A lives. Only one person lives between A and the one having a car Cadillac. F lives immediately below the one having a car Bedford. The one having a car Bedford lives on an even-numbered floor. Only three people live between the ones having a car Cadillac and Maruti. E lives immediately above C. E is not having a car Maruti. Only two people live between B and the one having a car Fargo. The one having a car Fargo lives below the floor on which B lives. The one having a car Fiat does not live immediately above D or immediately below B. D does not live immediately above or immediately below A. G does not have a car Ambassador. Question : How many people live between the floors on which D and the one having a car Bedford ?
A
One
B
Two
C
Three
D
Four
For a stable closed loop system, the gain at phase crossover frequency should always be:
A
< 20 dB
B
< 6 dB
C
> 6 dB
D
> 0 dB
Assertion (A): The phase angle plot in Bode diagram is not affected by the variation in the gain of the system. Reason(R): The variation in the gain of the system has no effect on the phase margin of the system.
A
Both A and R are true but R is correct explanation of A
B
Both A and R are true but R is correct explanation of A
C
A is true but R is false
D
A is false but R is true
Which one of the following statements is correct for gain margin and phase margin of two closed-loop systems having loop functions G(s) H(s) and exp(-s) G(s) H(s)?
A
Both gain and phase margins of the two systems will be identical
B
Both gain and phase margins of G(s) H(s) will be more
C
Gain margins of the two systems are the same but phase margins of G(s) H(s) will be more
D
Phase margins of the two systems are the same but gain margin of G(s) H(s) will be less
The critical value of gain for the system is 40. The system is operating at a gain of 20. The gain margin of the system is :
A
2 dB
B
3 dB
C
6 dB
D
4 dB
The transfer function of a discrete time LTI system is given by
$$H\left( z \right) = {{2 - {3 \over 4}{z^{ - 1}}} \over {1 - {3 \over 4}{z^{ - 1}} + {1 \over 8}{z^{ - 2}}}}$$
Consider the following statements:
S
1
: The system is stable and causal for
$$ROC:\left| z \right| > {1 \over 2}$$
S
2
: The system is stable but not causal for
$$ROC:\left| z \right| S
3
: The system is neither stable nor causal for
$$ROC:{1 \over 4} Which one of the following statements is valid?
A
Both S<sub>1</sub> and S<sub>2</sub> are true
B
Both S<sub>2</sub> and S<sub>3</sub> true
C
Both S<sub>1</sub> and S<sub>3</sub> are true
D
S<sub>1</sub>, S<sub>2</sub> and S<sub>3</sub> are all true
The critical value of gain for a system is 40 and gain margin is 6dB. The system is operating at a gain of:
A
20
B
40
C
80
D
120
Select the order in which the frequency should be maintained to enhance the stability of differentiator? Where fa -> Frequency at which gain =0 ; fb -> Gain limit frequency ; fc -> Unity gain bandwidth.
A
fa b c
B
fa > fb > fc
C
fb c > fa
D
fb c a
Which of the following statements is correct for a system with gain margin close to unity or a phase margin close to zero?
A
The system is relatively stable
B
The system is highly stable
C
The system is highly oscillatory
D
The system is stable
A system with gain margin close to unity and phase margin close to zero is :
A
Highly stable
B
Oscillatory
C
Relatively stable
D
Unstable