# Approximation of higher order models Objective Questions and Answers

1. The second derivative input signals modify which of the following?
a) The time constant of the system
b) Damping of the system
c) The gain of the system
d) The time constant and suppress the oscillations
Answer: The time constant and suppress the oscillations
2. 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
Answer: The system is highly oscillatory
3. Zero initial condition for a system means?
a) Input reference signal is zero
b) Zero stored energy
c) Initial movement of moving parts
d) System is at rest and no energy is stored in any of its components
Answer: System is at rest and no energy is stored in any of its components
4. On which of the following factors does the sensitivity of a closed loop system to gain changes and load disturbances depend?
a) Frequency
b) Loop gain
c) Forward gain
d) All of the mentioned
5. The output of a feedback control system must be a function of
a) Reference and output
b) Reference and input
c) Input and feedback signal
d) Output and feedback signal
6. Transfer function of a system is used to calculate which of the following?
a) The order of the system
b) The time constant
c) The output for any given input
Answer: The output for any given input
7. Which of the following statements is correct for any closed loop system?
a) All the co-efficient can have zero value
b) All the co-efficient are always non-zero
c) Only one of the static error co-efficient has a finite non-zero value
d) Only two of the static error co-efficient has a finite non-zero value
Answer: Only one of the static error co-efficient has a finite non-zero value
8. A control system with excessive noise, is likely to suffer from?
a) Saturation in amplifying stages
b) Loss of gain
c) Vibrations
d) Oscillations
9. The band width, in a feedback amplifier.
a) Remains unaffected
b) Decreases by the same amount as the gain increase
c) Increases by the same amount as the gain decrease
d) Decreases by the same amount as the gain decrease
Answer: Increases by the same amount as the gain decrease
10. The transient response, with feedback system, Decays quickly
a) True
b) False