Data visualization and signal analysis – MCQs – EE

1. Data visualization in MATLAB is used to:
(A) Graphically represent data
(B) Solve algebraic equations only
(C) Control motors
(D) Design transformers

2. The plot command in MATLAB is used for:
(A) 2D line plots
(B) Step response
(C) Bode plots only
(D) Matrix multiplication

3. The stem command is used to:
(A) Plot discrete data points
(B) Plot continuous functions
(C) Create histograms
(D) Compute FFT

4. The bar command in MATLAB is used for:
(A) Bar charts
(B) Line plots
(C) Pie charts
(D) Surface plots

5. The histogram command is used to:
(A) Visualize data distribution
(B) Create scatter plots
(C) Plot Bode plots
(D) Compute signal derivative

6. The scatter command is used for:
(A) Scatter plots of data points
(B) Continuous line plots
(C) 3D surface plots
(D) Step response

7. The subplot command is used to:
(A) Create multiple plots in one figure
(B) Plot in a new window only
(C) Plot bar charts only
(D) Compute FFT

8. The xlabel and ylabel commands are used to:
(A) Label axes
(B) Add legends
(C) Change colors
(D) Plot 3D surfaces

9. The title command is used to:
(A) Add a title to the plot
(B) Label the axes
(C) Plot multiple lines
(D) Compute FFT

10. The legend command is used to:
(A) Identify multiple plotted signals
(B) Label axes
(C) Change figure size
(D) Add grid

11. The grid on command is used to:
(A) Display a grid on the plot
(B) Add a legend
(C) Label axes
(D) Change plot color

12. The figure command is used to:
(A) Open a new figure window
(B) Plot within an existing figure only
(C) Create subplots only
(D) Compute FFT

13. The mesh command is used to:
(A) Create 3D mesh plots
(B) Plot 2D lines
(C) Plot bar charts
(D) Display scatter plots

14. The surf command is used for:
(A) 3D surface plots
(B) 2D line plots
(C) Histogram only
(D) Stem plots

15. FFT in MATLAB is computed using:
(A) fft()
(B) ifft()
(C) plot()
(D) mesh()

16. The ifft command is used to:
(A) Compute inverse FFT
(B) Compute FFT
(C) Plot signals
(D) Create histograms

17. The magnitude spectrum of a signal can be obtained using:
(A) abs(fft(signal))
(B) real(fft(signal))
(C) imag(fft(signal))
(D) plot(signal)

18. The phase spectrum is obtained using:
(A) angle(fft(signal))
(B) abs(fft(signal))
(C) real(signal)
(D) imag(signal)

19. The freqz command in MATLAB is used to:
(A) Plot frequency response of a digital filter
(B) Compute FFT only
(C) Plot step response
(D) Create bar plots

20. The filter command in MATLAB is used to:
(A) Apply digital filters to signals
(B) Plot 2D graphs
(C) Create histograms
(D) Compute FFT only

21. The conv command is used for:
(A) Convolution of two signals
(B) Plotting 3D surfaces
(C) Frequency response
(D) Creating scatter plots

22. The corrcoef command computes:
(A) Correlation coefficient between two signals
(B) Convolution
(C) FFT
(D) Step response

23. The xcorr command is used for:
(A) Cross-correlation of two signals
(B) Autocorrelation only
(C) Convolution only
(D) Filtering

24. The autocorr command computes:
(A) Autocorrelation of a signal
(B) Cross-correlation only
(C) FFT magnitude
(D) Step response

25. Signal sampling in MATLAB can be performed using:
(A) downsample() and upsample()
(B) fft() only
(C) plot() only
(D) filter() only

26. To smooth a noisy signal, MATLAB uses:
(A) smooth()
(B) fft()
(C) plot()
(D) mesh()

27. The findpeaks command is used to:
(A) Detect local maxima in a signal
(B) Compute FFT
(C) Plot 3D surfaces
(D) Filter signals

28. Signal energy can be computed using:
(A) sum(abs(signal).^2)
(B) fft(signal)
(C) filter(signal)
(D) plot(signal)

29. The rms command calculates:
(A) Root mean square of a signal
(B) Maximum value only
(C) Minimum value only
(D) FFT magnitude

30. Data visualization and signal analysis in MATLAB helps to:
(A) Understand and analyze system behavior
(B) Solve mechanical problems only
(C) Build transformers only
(D) Control hardware only