Discrete-Time Signals and Systems Quizzes - Test Your Understanding

Question 1

Which of the following systems does not exhibit linearity?

Accepted Answer

A system that squares the input signal.

Answer

A system that doubles the input signal.

Answer

A system that adds a constant to the input signal.

Answer

A system that delays the input signal by one sample.

Question 2

Which of the following applications of discrete-time signals and systems does NOT belong to the field of communications?

Accepted Answer

Image processing

Answer

Digital modulation

Answer

Error correction coding

Answer

Radar signal processing

Question 3

Arrange the following filters in the correct order of their frequency passbands: low-pass, band-pass, and notch.

Accepted Answer

Low-pass, band-pass, notch

Answer

Low-pass, notch, band-pass

Answer

Band-pass, low-pass, notch

Question 4

What is the transfer function of a system that performs a simple delay of M samples?

Accepted Answer

H(z) = z^(-M)

Answer

H(z) = z^M

Answer

H(z) = Mz

Answer

H(z) = 1/Mz

Question 5

Which of the following transforms is NOT a type of z-transform?

Accepted Answer

Fourier transform

Answer

Unilateral z-transform

Answer

Bilateral z-transform

Answer

Inverse z-transform

Question 6

What is the purpose of a digital-to-analog converter (DAC)?

Accepted Answer

To convert digital signals into analog signals

Answer

To convert analog signals into digital signals

Answer

To amplify digital signals

Answer

To filter digital signals

Question 7

Which of the following is NOT an application of discrete-time signals and systems?

Accepted Answer

Analog circuit design

Answer

Digital audio processing

Answer

Image processing

Answer

Control systems

Question 8

What is the computational complexity of the Fast Fourier Transform (FFT) algorithm?

Accepted Answer

O(N log N)

Answer

O(N^2)

Answer

O(N)

Answer

O(log N)

Question 9

Which characteristic below does NOT apply to discrete-time signals?

Accepted Answer

They are continuous in time.

Answer

They are defined at discrete points in time.

Answer

They can be represented as a series of numbers.

Answer

They can be processed digitally.

Question 10

Which of the following methods is appropriate for examining discrete-time systems in the frequency domain?

Accepted Answer

Z-Transform

Answer

Fourier Transform

Answer

Laplace Transform

Answer

Convolution

Question 11

What is the transfer function of a system with a frequency response H(ω) = 1/(1 + jω)?

Accepted Answer

1/(1 + jω)

Answer

1

Answer

jω

Answer

1/jω

Question 12

Which of the following filter types eliminates high-frequency noise from a signal?

Accepted Answer

Low-pass filter

Answer

High-pass filter

Answer

Band-pass filter

Answer

Band-stop filter

Question 13

To determine the frequency response of a discrete-time system, how do you use the z-transform?

Accepted Answer

Substitute z = e^(jw) into the system's z-transform and evaluate it on the unit circle.

Answer

Obtain the system's impulse response by taking the inverse z-transform of its frequency response.

Answer

Solve the system's differential equation in the frequency domain.

Question 14

What is the relationship between the Discrete Fourier Transform (DFT) and the Fourier transform?

Accepted Answer

The DFT is the discrete-time version of the Fourier transform.

Answer

The DFT is a more general form of the Fourier transform.

Answer

The DFT is a different transform from the Fourier transform.

Question 15

In digital signal processing, convolution is a mathematical operation that combines two discrete-time signals, x[n] and h[n], to produce a third signal, y[n]. Which of the following equations correctly calculates y[n]?

Accepted Answer

∑{k=-∞}^{∞} x[k]h[n-k]

Answer

x[n] + h[n]

Answer

x[n] * h[n]

Answer

∫_{-∞}^{∞} x(t)h(t-n) dt

Question 16

Which of the following is a fundamental property of discrete-time signals?

Accepted Answer

Quantized in time

Answer

Continuous in amplitude

Answer

Analog

Answer

Random in nature

Question 17

The sampling period of a discrete-time signal x[n] is the:

Accepted Answer

Time interval between successive samples

Answer

Inverse of the sampling rate

Answer

Total duration of the signal

Answer

Amplitude of the signal

Question 18

The complex exponential sequence x[n] = A^n is an example of a:

Accepted Answer

Geometric sequence

Answer

Harmonic sequence

Answer

Fibonacci sequence

Answer

Arithmetic sequence

Question 19

Which of the following frequency responses represents an ideal low-pass filter?

Accepted Answer

H(ω) = 1 for |ω| ≤ ωc, 0 otherwise

Answer

H(ω) = 0 for |ω| ≤ ωc, 1 otherwise

Answer

H(ω) = 1/|ω| for |ω| ≤ ωc, 0 otherwise

Answer

H(ω) = |ω| for |ω| ≤ ωc, 0 otherwise

Question 20

The unit sample response h[n] of a linear time-invariant (LTI) system is given by:

Accepted Answer

h[n] = (1/2π) ∫[0, 2π] H(ω)ejωn dω

Answer

h[n] = H(ω)ejωn

Answer

h[n] = ∫[0, 2π] H(ω) dω

Answer

h[n] = (2π) ∫[0, 2π] H(ω) dω

Question 21

Which of the following is a type of digital filter based on its impulse response?

Accepted Answer

Finite Impulse Response (FIR)

Answer

Autoregressive Moving Average (ARMA) Filter

Answer

Infinite Horizon Response (IHR)

Answer

Recursive Average Filter (RAF)

Question 22

The purpose of a decimation filter is to:

Accepted Answer

Reduce the sampling rate of a signal

Answer

Increase the sampling rate of a signal

Answer

Remove high-frequency noise from a signal

Answer

Enhance the low-frequency components of a signal