Test on Digital Signal Processing Fundamentals

Question 1: A signal is always an electric signal.

A. Ano

B. Ne

Explanation: The study materials state that people usually understand the term “signal” as “electric signal” but this is not 100 % correct.

Question 2: In the complex Fourier series, the coefficient for the negative k-th harmonic, c-k, is always identical to the coefficient for the positive k-th harmonic, ck.

A. Ano

B. Ne

Explanation: The study materials state that c-k is the complex conjugate of ck (c-k = ck*), not that they are identical. They are only identical if ck is purely real.

Question 3: Based on the study materials, what is a key characteristic of an Electrocardiogram (ECG) signal?

A. It is an image of the heart's electronic activity.

B. It has completely different characteristics compared to a human voice signal.

C. It is an acoustic elevation that causes media vibrations.

D. It shares similar characteristics with human voice signals.

Explanation: The study materials state that an Electrocardiogram (ECG) is an 'Image of the hart electronic activity' and has 'Completely different characteristics of the signal than the human voice signal'. Therefore, options 0 and 1 are correct. Option 2 describes sound, and option 3 contradicts the provided information.

Question 4: According to the study materials, what are the two main variants for describing a signal?

A. Only in the time domain as a signal waveform represented by a function or a graph.

B. Only in the frequency domain as a signal spectrum, expressed as a sum of orthogonal functions.

C. In both time domain as a signal waveform and frequency domain as a signal spectrum.

D. By its amplitude, angular frequency, and initial phase.

Explanation: The study materials explicitly state: 'Two variants of the signal description ▪ Signal description in time domain – signal waveform' and '▪ Signal description in frequency domain – signal spectrum'.

Question 5: The spectral coefficients for the rectangular signal example are expressed using the normalized sinc function as defined by MATLAB or Python.

A. Ano

B. Ne

Explanation: The study materials state that care should be taken because both MATLAB and Python use a slightly different, normalized sinc function, implying the given formula in the materials is not the normalized one used by these tools.