Worksheetsgroup B
Total questions: 10
Worksheet time: 5mins
Which statement best describes a continuous-time signal?
It is defined only at separate points like every minute or hour.
Data are available or measured at every instant over a continuous input.
It has only two possible values.
It can be seen only on a computer.
Which statement best describes a periodic continuous-time signal x(t)?
It changes only at separate time steps.
It repeats after a positive nonzero time T so that x(t + T) = x(t) for all t.
It never repeats and always increases.
It is only defined for negative time values.
Which MATLAB helper function generates a unit step sequence starting at n0 between n1 and n2?
sigadd
sigshift
stepseq
sigfold
Consider x(n) = cos(0.04πn) + 0.2 w(n) for 0 ≤ n ≤ 50, where w(n) is Gaussian random with zero mean and unit variance. Which phrase best describes x(n)?
A cosine with small random noise added
A straight line that never changes
A unit step that turns on at n = 10
Only random noise without pattern
Which tool is most helpful to see how a discrete sequence changes with n?
A plot of x(n) versus n
A paragraph of text
An audio recording
A thermometer
If a plot shows stems that start at zero and rise linearly from n = 0 to n = 9, which sequence part likely created it?
n[u(n) − u(n − 10)]
2δ(n + 2)
cos(0.04πn)
w(n) only
Any real-valued sequence x(n) can be decomposed into which two components?
Even and periodic
Even and odd
Odd and random
Periodic and random
According to the formulas, what is the expression for the odd part xo(n) of a sequence x(n)?
xo(n) = 1/2 [x(n) + x(−n)]
xo(n) = x(n) + x(−n)
xo(n) = 1/2 [x(n) − x(−n)]
xo(n) = x(−n)
What do the variables xe and xo represent in the MATLAB function evenodd?
Input time index and frequency index
The sum and product of x
The even and odd parts of x
Random noise added to x
In the discussion example, x(n) is created using u(n) − u(n − 10). What kind of signal shape does this produce, as shown in the plot title?
Sine wave
Triangular pulse
Rectangular pulse
Impulse train
