1
GATE ECE 2007
+1
-0.3
If E denotes expectation, the variance of a random variable X is given by
A
$$E\,\left[ {{X^2}} \right] - \,{E^2}\left[ X \right]$$
B
$$E\,\left[ {{X^2}} \right] + \,{E^2}\left[ X \right]$$
C
$$E\,\left[ {{X^2}} \right]$$
D
$${E^2}\left[ X \right]$$
2
GATE ECE 2001
+1
-0.3
The PDF of a Gaussian random variable X is given by $${p_x}(x) = \,{1 \over {3\sqrt {2\pi } }}\,\exp \,[ - \,{(x - 4)^2}/18]$$.

The probability of the event {X = 4} is

A
1/2
B
$$1/\left( {3\sqrt {2\,\pi } } \right)$$
C
0
D
1/4
3
GATE ECE 1998
+1
-0.3
The amplitude spectrum of a Gaussian pulse is
A
uniform
B
a sine function
C
Gaussian
D
an impulse function
4
GATE ECE 1998
+1
-0.3
The ACF of a rectangular pulse of duration T is
A
a rectangular pulse of duration T
B
a rectangular pulse of duration 2T
C
a triangular pulse of duration T
D
a triangular pulse of duration 2T
GATE ECE Subjects
Signals and Systems
Network Theory
Control Systems
Digital Circuits
General Aptitude
Electronic Devices and VLSI
Analog Circuits
Engineering Mathematics
Microprocessors
Communications
Electromagnetics
EXAM MAP
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