1
GATE ECE 2002
MCQ (Single Correct Answer)
+1
-0.3
The Fourier transform F $$\left\{ {{e^{ - t}}u(t)} \right\}$$ is equal to $${1 \over {1 + j2\pi f}}$$. Therefore, $$F\left\{ {{1 \over {1 + j2\pi t}}} \right\}$$ is
A
$${e^f}u(f)$$
B
$${e^{ - f}}$$ u(f)
C
$${e^f}u(f)$$
D
$${e^{ - f}}$$u(-f)
2
GATE ECE 2002
MCQ (Single Correct Answer)
+1
-0.3
Convolution of x(t + 5) with impulse function $$\delta \left( {t\, - \,7} \right)$$ is equal to
A
$$X\left( {t - 12} \right)$$
B
$$X\left( {t + 12} \right)$$
C
$$X\left( {t - 2} \right)$$
D
$$X\left( {t + 2} \right)$$
3
GATE ECE 2002
MCQ (Single Correct Answer)
+2
-0.6
The Laplace transform of a continuous - time signal x(t) is $$X\left( s \right) = {{5 - s} \over {{s^2} - s - 2}}$$. If the Fourier transform of tyhis signal exists, then x(t) is
A
$${e^{2t}}u\left( t \right) - 2\,{e^{ - t}}u\left( t \right)$$
B
$$ - {e^{2t}}u\left( { - t} \right) + 2\,{e^{ - t}}u\left( t \right)$$
C
$$ - {e^{2t}}u\left( { - t} \right) - 2\,{e^{ - t}}u\left( t \right)$$
D
$${e^{2t}}u\left( { - t} \right) - 2\,{e^{ - t}}u\left( t \right)$$
4
GATE ECE 2002
MCQ (Single Correct Answer)
+2
-0.6
If the impulse response of a discrete-time system is $$h\left[ n \right]\, = \, - {5^n}\,\,u\left[ { - n\, - 1} \right],$$ then the system function $$H\left( z \right)\,\,\,$$ is equal to
A
$${{ - z} \over {z - 5}}$$ and the system is stable.
B
$${z \over {z - 5}}$$ and the system is stable.
C
$${{ - z} \over {z - 5}}$$ and the system is unstable.
D
$${z \over {z - 5}}$$ and the system is unstable.