ECE 101 LAB 4: ALIASING DUE TO
UNDERSAMPLING | 2026 UPDATE
WITH COMPLETE SOLUTIONS.
148 Questions with Answers and Detailed Rationales
100 PERCENT GUARANTEED PASS
INSTANT DOWNLOAD ANSWERS INCLUDED
IMPORTANCE OF THIS DOCUMENT
This comprehensive examination preparation guide has been meticulously developed to help you succeed in the
ECE 101 LAB 4: ALIASING DUE TO UNDERSAMPLING | 2026 UPDATE WITH COMPLETE SOLUTIONS.. It
contains 148 carefully selected questions that reflect the most current exam content and testing strategies. Each
question is accompanied by a correct answer and a detailed rationale that explains the underlying
pathophysiology, pharmacology, or clinical reasoning.
Self-Assessment – Test your knowledge and Exam Preparation – Familiarize yourself with the
identify areas requiring further question format and content
study areas
Concept Reinforcement – Deepen your Confidence Building – Develop test-taking
understanding through strategies and reduce
evidence-based exam anxiety
rationales
Time Management – Practice answering
questions under simulated
exam conditions
Review Summary 148 Questions
Foundations - Application - ECE 101 LAB 4 Aliasing DUE TO Undersampling 2026 Update WITH Complete
Solutions Signals AND Systems / Digital Signal Processing Laboratory Undergraduate YEAR 2 Electrical AND
Computer Engineering
All answers with rationales
,Table of Contents
Content Area Questions Key Topics
Sampling Theorem AND 1-25 Sampled, Frequency, Alias, Filter, Signal
Nyquist RATE
Aliasing Phenomenon AND 26-50 Sampled, Frequency, Alias, Reconstructed, System
Frequency Folding
Undersampling Effects ON 51-75 Sampled, Frequency, Signal, Aliasing, Reconstructed
Signal Reconstruction
Anti-aliasing Filters AND 76-100 Sampled, Signal, Alias, Frequency, Reconstructed
Their Design
Sampling OF Sinusoidal 101-125 Sampled, Frequency, Signal, Filter, Low-pass
Signals AND BEAT
Frequencies
Frequency-domain Analysis 126-148 Sampled, Frequency, Aliasing, Signal, Sampling
OF Sampled Signals
TOTAL 148 All questions include answers and detailed rationales
,Section A - Sampling Theorem AND Nyquist RATE
Q1.
A continuous-time sinusoid of 7 kHz is sampled at 10 kHz. What is the apparent (alias)
frequency in the sampled sequence?
A. 3 kHz B. 7 kHz
C. 2 kHz D. 17 kHz
Correct: A - 3 kHz
Rationale:The Nyquist frequency is 5 kHz. The 7 kHz tone lies 2 kHz above Nyquist, so it
folds to 5 2 = 3 kHz. Aliasing maps f to |f k-fs| for integer k, giving 3 kHz.
Why the other answers are wrong:
B. 7 kHz exceeds the Nyquist frequency of 5 kHz and cannot appear directly in the sampled
spectrum.
C. 2 kHz is the fold distance from Nyquist, not the alias frequency itself.
D. 17 kHz is a sum frequency, not a valid alias in the baseband [0, fs/2].
Reference: Oppenheim & Schafer, Discrete-Time Signal Processing, 3rd Ed., Ch. 4
Q2.
An anti-aliasing low-pass filter is placed before an ADC sampling at 48 kHz. To prevent
aliasing of out-of-band noise, the filter's stopband attenuation should begin at which
frequency?
A. 24 kHz B. 48 kHz
C. 96 kHz D. 12 kHz
Correct: A - 24 kHz
Rationale:The Nyquist frequency is fs/2 = 24 kHz. Components above 24 kHz fold into the
baseband, so the anti-aliasing filter must attenuate them before sampling; the stopband
should begin at the Nyquist frequency.
Why the other answers are wrong:
B. 48 kHz is the sampling rate, not the folding boundary.
C. 96 kHz is twice the sampling rate and is irrelevant to the first Nyquist zone.
D. 12 kHz is fs/4; attenuation starting there would unnecessarily limit the usable baseband.
Reference: Sedra & Smith, Microelectronic Circuits, 8th Ed., Ch. 15 (Data Conversion)
Page 3
, Section A - Sampling Theorem AND Nyquist RATE
Q3.
A 1.2 kHz sine wave is sampled at 2 kHz. The resulting sampled sequence is passed
through an ideal reconstruction filter with cutoff at 1 kHz. What frequency is observed at
the output?
A. 800 Hz B. 1.2 kHz
C. 200 Hz D. 2.8 kHz
Correct: A - 800 Hz
Rationale:Nyquist is 1 kHz; the 1.2 kHz tone folds to 2·1 " 1.2 = 0.8 kHz = 800 Hz. The
reconstruction filter passes this alias, so 800 Hz appears at the output.
Why the other answers are wrong:
B. 1.2 kHz exceeds Nyquist and cannot be represented unambiguously.
C. 200 Hz is the fold distance from Nyquist, not the alias frequency.
D. 2.8 kHz is an image frequency outside the reconstruction filter's passband.
Reference: Proakis & Manolakis, Digital Signal Processing, 4th Ed., Ch. 1
Q4.
In a laboratory FFT display, a tone appears at 4.3 kHz when the ADC samples at 10 kHz.
Which actual input frequency is a plausible source of this alias?
A. 5.7 kHz B. 4.3 kHz
C. 1.4 kHz D. 14.3 kHz
Correct: A - 5.7 kHz
Rationale:Aliases satisfy f_alias = |f " k·fs|. For fs = 10 kHz and f_alias = 4.3 kHz, f = 5.7 kHz
(k = 1) is a valid source: 10 5.7 = 4.3 kHz.
Why the other answers are wrong:
B. 4.3 kHz is the observed alias, not necessarily the true input.
C. 1.4 kHz would alias to 1.4 kHz, not 4.3 kHz.
D. 14.3 kHz aliases to 4.3 kHz only if k = 1 gives 14.3 10 = 4.3, but 14.3 kHz is above the first
Nyquist zone and would require a different k; it is less plausible than 5.7 kHz.
Reference: Lyons, Understanding Digital Signal Processing, 3rd Ed., Ch. 2
Q5.
Which statement correctly describes the relationship between sampling rate and aliasing
for a bandlimited signal?
A. Aliasing is avoided if fs > 2-fmax, where B. Aliasing is avoided if fs = 2-fmax exactly.
fmax is the highest frequency component.
Page 4
UNDERSAMPLING | 2026 UPDATE
WITH COMPLETE SOLUTIONS.
148 Questions with Answers and Detailed Rationales
100 PERCENT GUARANTEED PASS
INSTANT DOWNLOAD ANSWERS INCLUDED
IMPORTANCE OF THIS DOCUMENT
This comprehensive examination preparation guide has been meticulously developed to help you succeed in the
ECE 101 LAB 4: ALIASING DUE TO UNDERSAMPLING | 2026 UPDATE WITH COMPLETE SOLUTIONS.. It
contains 148 carefully selected questions that reflect the most current exam content and testing strategies. Each
question is accompanied by a correct answer and a detailed rationale that explains the underlying
pathophysiology, pharmacology, or clinical reasoning.
Self-Assessment – Test your knowledge and Exam Preparation – Familiarize yourself with the
identify areas requiring further question format and content
study areas
Concept Reinforcement – Deepen your Confidence Building – Develop test-taking
understanding through strategies and reduce
evidence-based exam anxiety
rationales
Time Management – Practice answering
questions under simulated
exam conditions
Review Summary 148 Questions
Foundations - Application - ECE 101 LAB 4 Aliasing DUE TO Undersampling 2026 Update WITH Complete
Solutions Signals AND Systems / Digital Signal Processing Laboratory Undergraduate YEAR 2 Electrical AND
Computer Engineering
All answers with rationales
,Table of Contents
Content Area Questions Key Topics
Sampling Theorem AND 1-25 Sampled, Frequency, Alias, Filter, Signal
Nyquist RATE
Aliasing Phenomenon AND 26-50 Sampled, Frequency, Alias, Reconstructed, System
Frequency Folding
Undersampling Effects ON 51-75 Sampled, Frequency, Signal, Aliasing, Reconstructed
Signal Reconstruction
Anti-aliasing Filters AND 76-100 Sampled, Signal, Alias, Frequency, Reconstructed
Their Design
Sampling OF Sinusoidal 101-125 Sampled, Frequency, Signal, Filter, Low-pass
Signals AND BEAT
Frequencies
Frequency-domain Analysis 126-148 Sampled, Frequency, Aliasing, Signal, Sampling
OF Sampled Signals
TOTAL 148 All questions include answers and detailed rationales
,Section A - Sampling Theorem AND Nyquist RATE
Q1.
A continuous-time sinusoid of 7 kHz is sampled at 10 kHz. What is the apparent (alias)
frequency in the sampled sequence?
A. 3 kHz B. 7 kHz
C. 2 kHz D. 17 kHz
Correct: A - 3 kHz
Rationale:The Nyquist frequency is 5 kHz. The 7 kHz tone lies 2 kHz above Nyquist, so it
folds to 5 2 = 3 kHz. Aliasing maps f to |f k-fs| for integer k, giving 3 kHz.
Why the other answers are wrong:
B. 7 kHz exceeds the Nyquist frequency of 5 kHz and cannot appear directly in the sampled
spectrum.
C. 2 kHz is the fold distance from Nyquist, not the alias frequency itself.
D. 17 kHz is a sum frequency, not a valid alias in the baseband [0, fs/2].
Reference: Oppenheim & Schafer, Discrete-Time Signal Processing, 3rd Ed., Ch. 4
Q2.
An anti-aliasing low-pass filter is placed before an ADC sampling at 48 kHz. To prevent
aliasing of out-of-band noise, the filter's stopband attenuation should begin at which
frequency?
A. 24 kHz B. 48 kHz
C. 96 kHz D. 12 kHz
Correct: A - 24 kHz
Rationale:The Nyquist frequency is fs/2 = 24 kHz. Components above 24 kHz fold into the
baseband, so the anti-aliasing filter must attenuate them before sampling; the stopband
should begin at the Nyquist frequency.
Why the other answers are wrong:
B. 48 kHz is the sampling rate, not the folding boundary.
C. 96 kHz is twice the sampling rate and is irrelevant to the first Nyquist zone.
D. 12 kHz is fs/4; attenuation starting there would unnecessarily limit the usable baseband.
Reference: Sedra & Smith, Microelectronic Circuits, 8th Ed., Ch. 15 (Data Conversion)
Page 3
, Section A - Sampling Theorem AND Nyquist RATE
Q3.
A 1.2 kHz sine wave is sampled at 2 kHz. The resulting sampled sequence is passed
through an ideal reconstruction filter with cutoff at 1 kHz. What frequency is observed at
the output?
A. 800 Hz B. 1.2 kHz
C. 200 Hz D. 2.8 kHz
Correct: A - 800 Hz
Rationale:Nyquist is 1 kHz; the 1.2 kHz tone folds to 2·1 " 1.2 = 0.8 kHz = 800 Hz. The
reconstruction filter passes this alias, so 800 Hz appears at the output.
Why the other answers are wrong:
B. 1.2 kHz exceeds Nyquist and cannot be represented unambiguously.
C. 200 Hz is the fold distance from Nyquist, not the alias frequency.
D. 2.8 kHz is an image frequency outside the reconstruction filter's passband.
Reference: Proakis & Manolakis, Digital Signal Processing, 4th Ed., Ch. 1
Q4.
In a laboratory FFT display, a tone appears at 4.3 kHz when the ADC samples at 10 kHz.
Which actual input frequency is a plausible source of this alias?
A. 5.7 kHz B. 4.3 kHz
C. 1.4 kHz D. 14.3 kHz
Correct: A - 5.7 kHz
Rationale:Aliases satisfy f_alias = |f " k·fs|. For fs = 10 kHz and f_alias = 4.3 kHz, f = 5.7 kHz
(k = 1) is a valid source: 10 5.7 = 4.3 kHz.
Why the other answers are wrong:
B. 4.3 kHz is the observed alias, not necessarily the true input.
C. 1.4 kHz would alias to 1.4 kHz, not 4.3 kHz.
D. 14.3 kHz aliases to 4.3 kHz only if k = 1 gives 14.3 10 = 4.3, but 14.3 kHz is above the first
Nyquist zone and would require a different k; it is less plausible than 5.7 kHz.
Reference: Lyons, Understanding Digital Signal Processing, 3rd Ed., Ch. 2
Q5.
Which statement correctly describes the relationship between sampling rate and aliasing
for a bandlimited signal?
A. Aliasing is avoided if fs > 2-fmax, where B. Aliasing is avoided if fs = 2-fmax exactly.
fmax is the highest frequency component.
Page 4
