Test: Frequency Domain Analysis of Control Systems - 1 - Electronics and Communication Engineering (ECE) MCQ

- The Bode diagram is used in control systems to analyze the frequency response of linear time-invariant systems.
- It is particularly useful for linear feedback control systems because it helps in assessing system stability and performance.
- Bode plots illustrate how the gain and phase of a system vary with frequency, aiding in the design and tuning of controllers.
- Non-linear systems are not typically analyzed using Bode plots due to their complex, non-linear behavior.
- Therefore, the correct answer is D: linear feedback control system only.

With no-pole at origin, initial slope will be OdB/decade.
For n-pole at origin, initial slope will be -20 ndB/decade.

Hence, time constant = T= 5 seconds

Given system is of type-1 and order-2, therefore its polar plot will be as shown below.

Hence, the polar plot will neither cross the real axis nor the imaginary axis.

DC gain = 5

100 [4ε² (1 – ε²)] = 3
400 ε² – 400 ε⁴ = 3
400 x² – 400 x + 3 = 0  
x² – x + 0.0075 = 0
ξ² = 0.99244 , ξ² = 0.00755
ξ = 0.99 , ξ = 0.08689
If resonant peak > 1 then

ω_n = 7 rad/s

K = 49 × 5 = 245