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This set of Communication Engineering Multiple Choice Questions & Answers (MCQs) focuses on Communication Engineering Set 7
Q1 | In an M-ary signalling scheme two or more bits are grouped together to form a
- chip
- symbol
- byte
- pattern
Q2 | M-ary signalling techniques are not sensitive to timing jitters.
- true
- false
Q3 | M-ary modulation schemes have very good power efficiency.
- true
- false
Q4 | What is the radius of the circle in M-ary PSK on which message points are equaly spaced?
- √es
- √eb
- eb
- es
Q5 | As the value of M the bandwidth efficiency
- increases, same.
- increases, decreases
- increases, increases
- decreases, same
Q6 | The power efficiency of the M ary PSK decreases because of the
- freely packed constellation
- increment of bandwidth efficiency
- fixed null bandwidth
- densely packed constellation
Q7 | In QAM, the amplitude is and phase is
- varied, constant
- varied, varied
- constant, varied
- constant, constant
Q8 | M-ary QAM signal have constant energy per symbol.
- true
- false
Q9 | In comparison to M-ary PSK, M-ary QAM bandwidth efficiency is and power efficiency is
- identical, superior
- less, superior
- identical, identical
- superior, superior
Q10 | The bandwidth efficiency of an M-ary FSK signal with in M.
- constant, increase
- increases, increase
- decreases, increase
- decreases, decrease
Q11 | Power efficiency of M-ary FSK increases, since
- constellation is densely packed
- m signals are non-orthogonal
- fixed null bandwidth
- m-signals are orthogonal
Q12 | The method in which the tail of one pulse smears into adjacent symbol interval is called as
- intersymbol interference
- interbit interference
- interchannel interference
- none of the mentioned
Q13 | If each pulse of the sequence to be detected is in shape, the pulse can be detected without ISI.
- sine
- cosine
- sinc
- none of the mentioned
Q14 | What is symbol rate packing?
- maximum possible symbol transmission rate
- maximum possible symbol receiving rate
- maximum bandwidth
- maximum isi value allowed
Q15 | A nyquist pulse is the one which can be represented by shaped pulse multiplied by another time function.
- sine
- cosine
- sinc
- none of the mentioned
Q16 | Examples of nyquist filters are
- root raised cosine filter
- raised cosine filter
- root raised & raised cosine filter
- none of the mentioned
Q17 | The minimum nyquist bandwidth for the rectangular spectrum in raised cosine filter is
- 2t
- 1/2t
- t2
- 2/t
Q18 | Roll off factor is the fraction of
- excess bandwidth and absolute bandwidth
- excess bandwidth and minimum nyquist bandwidth
- absolute bandwidth and minimum nyquist bandwidth
- none of the mentioned
Q19 | A pulse shaping filter should satisfy two requirements. They are
- should be realizable
- should have proper roll off factor
- should be realizable & have proper roll off factor
- none of the mentioned
Q20 | Examples of double side band signals are
- ask
- psk
- ask & psk
- none of the mentioned
Q21 | ISI is by increasing channel bandwidth.
- maximized
- minimized
- zero
- infinite
Q22 | Why is pulse shaping technique used?
- to increase isi
- to increase spectral width of modulated signal
- to reduce isi
- to reduce power spectral density
Q23 | Raised cosine filter does not satisfy Nyquist criteria.
- true
- false
Q24 | As the roll off factor in raised cosine rolloff filter the occupied bandwidth
- manchester
- faraday
- graham bell
- nyquist
Q25 | Gaussian pulse shaping filter follows Nyquist criterion.
- true
- false