1
GATE ECE 2009
MCQ (Single Correct Answer)
+2
-0.6
A system with transfer function H(z) has impulse response h(.) defined as h(2) = 1, h(3) = - 1 and h (k) = 0 otherwise. Consider the following statements.
S1: H(z) is a low-pass filter.
S2: H(z) is an FIR filter.

Which of the following is correct?

A
Only S2 is true
B
Both S1 and S2 are false.
C
Both S1 and S2 are true, and S2 is a reason for S1.
D
Both S1 and S2 are true, but S2 is not a reason for S1.
2
GATE ECE 2009
MCQ (Single Correct Answer)
+2
-0.6
An LTI system having transfer function $${{{s^2} + 1} \over {{s^2} + 2s + 1}}$$ and input x(t) = sin (t + 1) is in steady state. The output is sampled at a rate $${\omega _s}\,\,rad/s$$ to obtain the final output {y(k)}. Which of the following is true?
A
y(.) is zero for all sampling frequencies $${\omega _s}$$
B
y(.) is nonzero for all sampling frequencies $${\omega _s}$$
C
y(.) is nonzero for $${\omega _s}$$ > 2, but zero for $${\omega _s}$$ < 2
D
y(.) is zero for $${\omega _s}$$ > 2, but nonzero for $${\omega _s}$$ < 2
3
GATE ECE 2009
MCQ (Single Correct Answer)
+2
-0.6
The 4-point Discrete Fourier Transform (DFT) of a discrete time sequence $$\left\{ {1,\,0,\,2,\,3} \right\}$$ is
A
$$\left[ {0,\, - 2 + 2j,\,2,\, - 2 - 2j} \right]$$
B
$$\left[ {2,\,2 + 2j,\,6,\,2\, - 2j} \right]$$
C
$$\left[ {6,\,1 - 3j,\,2,\,1 + 3j} \right]$$
D
$$\left[ {6,\, - 1 + 3j,\,0,\, - 1\, - 3j} \right]$$
4
GATE ECE 2009
MCQ (Single Correct Answer)
+1
-0.3
A function is given by f(t) = sin2t +cos2t . Which of the following is true?
A
f has frequency components at 0 and $$1/2\mathrm\pi$$ Hz
B
f has frequency components at 0 and $$1/\mathrm\pi$$ Hz
C
f has frequency components at $$1/2\mathrm\pi$$ and $$1/\mathrm\pi$$ Hz
D
f has frequency components at 0, $$1/2\mathrm\pi$$ and $$1/\mathrm\pi$$ Hz