Master of Electrical Engineering Flashcards
7 cards from real ME or MEng Master of Engineering practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Master of Electrical Engineering flashcards as text
In a switched-mode power supply, the 'right-half-plane (RHP) zero' in the boost converter transfer function is problematic because it:
Answer: Adds 90° phase lag while increasing gain, limiting achievable control bandwidth
An RHP zero increases gain at +20 dB/decade but simultaneously adds phase lag like a pole, constraining the control loop bandwidth to well below the RHP zero frequency.
For a linear time-invariant system, the condition for BIBO (bounded-input bounded-output) stability is:
Answer: All poles of the transfer function lie in the open left-half s-plane
A continuous-time LTI system is BIBO stable if and only if all poles of H(s) have negative real parts (lie strictly in the left-half plane).
In power electronics, what is the purpose of 'dead time' inserted between gate signals of complementary switches in a half-bridge converter?
Answer: To prevent shoot-through (cross-conduction) where both switches conduct simultaneously
Dead time ensures both high-side and low-side switches are off simultaneously before the complementary switch turns on, preventing a low-impedance short-circuit path.
A digital FIR filter has linear phase if and only if its impulse response h[n] satisfies:
Answer: h[n] = -h[N-1-n] (antisymmetric) or h[n] = h[N-1-n] (symmetric)
Linear phase in FIR filters requires the impulse response to be either symmetric (Type I/II) or antisymmetric (Type III/IV) about its midpoint.
In optical fiber communications, 'chromatic dispersion' causes pulse broadening because:
Answer: Different wavelength components travel at different group velocities in the fiber
Chromatic dispersion arises because the fiber's refractive index (and thus group velocity) varies with wavelength, spreading out spectrally diverse pulses.
In the design of a phase-shifted full-bridge DC-DC converter, what enables zero-voltage switching (ZVS) for the primary switches?
Answer: Resonance between transformer leakage inductance and switch output capacitance
ZVS is achieved when the energy stored in the transformer leakage inductance is sufficient to fully charge/discharge the switch output capacitances before turn-on, allowing switching at zero voltage.
The Bode gain-phase relationship (Bode's integral theorem) for a minimum-phase system states that:
Answer: Phase response is uniquely determined by the gain (magnitude) response
For minimum-phase systems, the phase response is uniquely determined by the magnitude response via the Hilbert transform relationship, so specifying gain fully determines phase.