Signals and Control Systems Flashcards
7 cards from real BEE practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Signals and Control Systems flashcards as text
The state-space representation ẋ = Ax + Bu, y = Cx + Du describes a system. The eigenvalues of matrix A correspond to:
Answer: The poles of the transfer function
The eigenvalues of the system matrix A are identical to the poles of the transfer function, determining the system's natural modes and stability.
Which of the following correctly describes the difference between discrete Fourier Transform (DFT) and the continuous Fourier Transform (CFT)?
Answer: DFT operates on a finite number of samples and produces a periodic discrete spectrum
The DFT takes N discrete-time samples and outputs N discrete frequency samples, effectively treating the signal as periodic with period N.
A closed-loop control system is said to be type 1 if its open-loop transfer function has:
Answer: One pole at the origin
The system type equals the number of open-loop poles at the origin (s = 0); a type 1 system has exactly one integrator in the open-loop path.
The steady-state error for a type 1 system subjected to a ramp input (r(t) = t·u(t)) is:
Answer: 1/Kv (a finite constant)
A type 1 system tracks a ramp with a finite steady-state error equal to 1/Kv, where Kv is the velocity error constant.
The unilateral Laplace transform is preferred over the bilateral transform for analyzing systems with initial conditions because:
Answer: It automatically incorporates initial conditions into the transform
The unilateral Laplace transform, starting the integral at t = 0⁻, naturally incorporates initial conditions through derivative transform properties.
In the Nyquist stability criterion, the number of closed-loop unstable poles Z is given by:
Answer: Z = N + P
The Nyquist criterion relates Z (unstable closed-loop poles) to N (clockwise encirclements of −1) and P (unstable open-loop poles) by Z = N + P.
Which type of signal has a Fourier series representation with discrete spectral components?
Answer: Periodic power signal
Periodic signals are represented by Fourier series with energy concentrated at discrete harmonically related frequencies.