1
GATE ECE 2013
MCQ (Single Correct Answer)
+2
-0.6
Bits 1 and 0 are transmitted with equal probability. At the receiver, the pdf of the respective received signals for both bits are as shown below. GATE ECE 2013 Communications - Random Signals and Noise Question 43 English

The optimum threshold to achieve minimum bit error rate (BER) is

A
$${1 \over 2}$$
B
$${4 \over 5}$$
C
1
D
$${3 \over 2}$$
2
GATE ECE 2011
MCQ (Single Correct Answer)
+2
-0.6
X(t) is a stationary random process with autocorrelation function Rx$$\left( \tau \right)$$= exp$$\left( { - \pi {\tau ^2}} \right)$$. This process is passed through the system shown below. The power spectral density of the output process Y(t) is GATE ECE 2011 Communications - Random Signals and Noise Question 45 English
A
$$\left( {4\,{\pi ^2}{f^2} + 1} \right)\,\exp \left( { - \pi {f^2}} \right)$$
B
$$\left( {4\,{\pi ^2}{f^2} - 1} \right)\,\exp \left( { - \pi {f^2}} \right)$$
C
$$\left( {4\,{\pi ^2}{f^2} + 1} \right)\,\exp \left( { - \pi f} \right)$$
D
$$\left( {4\,{\pi ^2}{f^2} - 1} \right)\,\exp \left( { - \pi f} \right)$$
3
GATE ECE 2010
MCQ (Single Correct Answer)
+2
-0.6
X(t) is a stationary process with the power spectral density Sx(f) > 0 for all f. The process is passed through a system shown below. GATE ECE 2010 Communications - Random Signals and Noise Question 46 English

Let Sy(f) be the power spectral density of Y(t). Which one of the following statements is correct?

A
Sy(f) > 0 for all f
B
Sy(f) > 0 for $$\left| f \right|$$ > 1 kH
C
Sy(f) > 0 for f = nf0, f0 = 2kHz, n any integer
D
Sy(f) > 0 for f = (2n + 1)f0, f0 = 1 kHz, n any integer
4
GATE ECE 2008
MCQ (Single Correct Answer)
+2
-0.6
Noise with double-sided power spectral density of K over all frequencies is passed through a RC low pass filter with 3-dB cut-off frequency of fc. The noise power at the filter output is
A
K
B
K fc
C
K $$\pi $$ fc
D
$$\infty $$
GATE ECE Subjects
EXAM MAP
Medical
NEETAIIMS
Graduate Aptitude Test in Engineering
GATE CSEGATE ECEGATE EEGATE MEGATE CEGATE PIGATE IN
Civil Services
UPSC Civil Service
Defence
NDA
Staff Selection Commission
SSC CGL Tier I
CBSE
Class 12