Exam 1 Flashcards
A discrete-time signal x[n] is only defined for integer values of the independent variable n
True
The discrete-time unit impulse signal 𝝳[n] is 0, for n=0 and 1 for all other values of n ≠ 0
False
(𝝳[n] is 1, for n=0 and 0 for all other values of n ≠ 0)
The period of x[n] = cos((π/2)n) is
(2, 4, π/2, 8)
4
Which of the following basic signals is NOT covered in the videos and reading
The unit step u[n]
The unit impulse 𝝳[n]
Exponential signals
Tangential signals
Tangential signals
If you double the input to a linear system, the output will also be doubled.
True
If you delay the input to a time-invariant system by 5 samples, the output will also be delayed by 5 samples.
True
The output of a causal system only depends on future values of the input.
False
(only depends on present & past values of the input)
The system below illustrates a parallel connection of the systems S1 and S2
-> [S1] -> [S2] ->
False
(series cascade)
Knowing the impulse response h[n] for a linear, time-invariant system allows us to find the output y[n] for any input x[n].
True
x[n] * (h₁[n] + h₂[n]) = x[n] * h₁[n] + x[n] * h₂[n]
True
Which of the following properties of convolution is NOT covered in the reading and videos
Commutative
Distributive
Conjunctive
Associative
Conjunctive
If an LTI system is causal, then the impulse response h[n] = -1 for n<0
False
(then the impulse response h[n] = 0 for n<0)
If an LTI system is stable, then the impulse response satisfies sum(n=-infinity to infinity)abs(h[n])<infinity
True
If h[n] is the impulse response for an LTI system, and g[n] is the impulse response for the inverse system, then g[n] + h[n] = 0
False
g[n] * h[n] = 𝝳[n]
x[n] * 𝝳[n] = x[n]