1. Frequency-domain analysis deals with system behavior in terms of:
(A) Time
(B) Frequency
(C) Amplitude
(D) Phase only
2. The Bode plot of a system represents:
(A) Amplitude vs time
(B) Frequency vs time
(C) Magnitude and phase vs frequency
(D) Voltage vs current
3. The Bode plot is generally drawn on:
(A) Linear scale
(B) Semi-log scale
(C) Log-log scale
(D) Exponential scale
4. The slope of a magnitude plot decreases by 20 dB/decade for each:
(A) Zero
(B) Pole
(C) Integrator
(D) Differentiator
5. The slope of a magnitude plot increases by 20 dB/decade for each:
(A) Pole
(B) Zero
(C) Integrator
(D) Feedback loop
6. The point where the slope of a Bode magnitude plot changes is called the:
(A) Phase margin point
(B) Break or corner frequency
(C) Cutoff frequency
(D) Resonant frequency
7. The gain margin of a system is measured at the frequency where:
(A) Phase is zero degrees
(B) Phase is minus 180 degrees
(C) Magnitude is zero decibels
(D) Phase is plus 90 degrees
8. The phase margin is measured at the frequency where:
(A) Phase is zero degrees
(B) Magnitude is zero decibels
(C) Phase is minus 180 degrees
(D) Magnitude is maximum
9. For a stable feedback system, the gain margin should be:
(A) Positive
(B) Negative
(C) Zero
(D) Infinite
10. A Nyquist plot represents the relationship between:
(A) Magnitude and phase
(B) Real and imaginary components of the transfer function
(C) Amplitude and time
(D) Input and output directly
11. The Nyquist stability criterion helps determine:
(A) Steady-state error
(B) Time constant
(C) Stability of a closed-loop system
(D) Bandwidth
12. In a Nyquist plot, encirclement of the point (–1, 0) indicates:
(A) Stability
(B) Instability
(C) Resonance
(D) Damping
13. If the Nyquist plot does not encircle the critical point and the open-loop system has no poles in the right half-plane, the system is:
(A) Stable
(B) Unstable
(C) Marginally stable
(D) Oscillatory
14. The root locus method shows how the locations of system poles change with variation in:
(A) Frequency
(B) Gain
(C) Phase
(D) Damping ratio
15. The root locus starts from:
(A) Zeros of the open-loop transfer function
(B) Poles of the open-loop transfer function
(C) Imaginary axis
(D) Unit circle
16. The root locus ends at:
(A) Zeros of the open-loop transfer function
(B) Poles of the open-loop transfer function
(C) Origin
(D) Real axis
17. The number of root locus branches is equal to the number of:
(A) Zeros
(B) Poles
(C) Feedback loops
(D) Time constants
18. On the real axis, the root locus exists where the total number of poles and zeros to the right is:
(A) Even
(B) Odd
(C) Zero
(D) Infinite
19. The intersection of the root locus with the imaginary axis indicates:
(A) The system’s gain margin
(B) The frequency of oscillation at the stability limit
(C) The damping ratio
(D) The system’s steady-state value
20. The root locus technique was developed by:
(A) Hendrik Bode
(B) Harry Nyquist
(C) W. R. Evans
(D) James Maxwell
21. In Bode plots, the frequency range over which the magnitude remains within 3 dB of its low-frequency value is known as:
(A) Stability range
(B) Bandwidth
(C) Gain range
(D) Phase margin
22. In a Nyquist plot, clockwise encirclement of the critical point indicates:
(A) A pole in the left-half-plane
(B) A pole in the right-half-plane
(C) A zero on the imaginary axis
(D) A stable system
23. Increasing the system gain moves the closed-loop poles on the root locus:
(A) Toward the zeros
(B) Toward the poles
(C) Toward the imaginary axis
(D) Toward the origin
24. The intersection of magnitude and phase plots in Bode analysis determines:
(A) Resonant frequency
(B) Gain crossover frequency
(C) Damping ratio
(D) Steady-state error
25. The Nyquist plot of a stable system typically lies:
(A) Around the origin
(B) Entirely in the right-half-plane
(C) Entirely in the left-half-plane
(D) Along the imaginary axis