Signals

Question 1
Marks : +2 | -2
Pass Ratio : 100%
Properties of impulse function are
Symmetry
Time scaling
Shifting
All of the mentioned
Explanation:
Some of the properties of impulse function are symmetry, time scaling and shifting.
Question 2
Marks : +2 | -2
Pass Ratio : 100%
A base-band signal can be up-converted using
Sine wave
Cosine wave
Filtering
None of the mentioned
Explanation:
A base-band signal can be up-converted to band-pass filter by applying cosine wave.
Question 3
Marks : +2 | -2
Pass Ratio : 100%
A band-pass signal can be down-converted using
Sine wave
Cosine wave
Time delayed wave
None of the mentioned
Explanation:
For down-conversion of a band-pass signal also cosine signal is used and multiplied with it.
Question 4
Marks : +2 | -2
Pass Ratio : 100%
Properties of Fourier transform are
Duality property
Time shifting property
Modulation property
All of the mentioned
Explanation:
Some of the properties of Fourier transform are duality property, time scaling property, time shifting property, modulation property and many more.
Question 5
Marks : +2 | -2
Pass Ratio : 100%
Random things in a communication system are
Timing offset
Device frequency
Attenuation
All of the mentioned
Explanation:
Some of the random things in the communication system are noise in the channel, attenuation, fading, channel filtering, device frequency, phase and timing offset.
Question 6
Marks : +2 | -2
Pass Ratio : 100%
Fourier transform of a signal gives the
Frequency content
Bandwidth
Frequency content & Bandwidth
None of the mentioned
Explanation:
Fourier transform of a signal give the frequency content and also determines the bandwidth of the signal.
Question 7
Marks : +2 | -2
Pass Ratio : 100%
Which can be used for periodic and non periodic?
Fourier series
Fourier transforms
Fourier series & transforms
None of the mentioned
Explanation:
Fourier series is limited to only periodic signals where as Fourier transforms and laplace transforms can be used for both periodic and non periodic signals.
Question 8
Marks : +2 | -2
Pass Ratio : 100%
ADSL has _____ information channels.
One
Three
Four
None of the mentioned
Explanation:
Asymmetric digital subscriber line has three information channels – a high speed downstream channel, ISDN channel and medium speed duplex channel.
Question 9
Marks : +2 | -2
Pass Ratio : 100%
In down-conversion multiplication with cosine wave is followed by
Low pass filter
High pass filter
Bandpass filter
Bandstop filter
Explanation:
Downconversion of bandpass signal includes multiplication with sine wave followed by low pass filtering.
Question 10
Marks : +2 | -2
Pass Ratio : 100%
In the digital communication system, signals in different frequency bands are
Orthogonal
Non orthogonal
Orthogonal & Non orthogonal
None of the mentioned
Explanation:
In digital communication system, signals from different frequency bands are orthogonal thus interference won’t occur.