MCQ in Digital and Data Communication Networks Part 10 | ECE Board

This is the Multiple Choice Questions Part 10 of the Series in Digital and Data Communication Networks as one of the Communications Engineering topic. In Preparation for the ECE Board Exam make sure to expose yourself and familiarize in each and every questions compiled here taken from various sources including but not limited to past Board Examination Questions in Electronic System and Technologies, Communications Books, Journals and other Communications References.

MCQ Topic Outline included in ECE Board Exam Syllabi

• MCQ in Bit and and Binary Transmission
• MCQ in Signaling Rate
• MCQ in Error Probability, Digital Filtering, Switching, Packet Circuit, Vertical Circuit
• MCQ in Open systems Interconnection
• MCQ in Multiplying, Modulation and Synchronization
• MCQ in Pulse Code Modulation, Companding, Encoding, Bandwidth and Signal to Noise Ratio
• MCQ in Delta Modulation, Slope Overload, Adaptive Delta Modulation, Codes and Protocol
• MCQ in Error Detection and Correction, Digital Carrier systems
• MCQ in Frequency Shift Keying, Phase Shift Keying, Differential Phase Shift keying
• MCQ in DC nature of data transmission, loops, Neutral and Polar
• MCQ in Binary transmission and the concept of time
• MCQ in Asynchronous and Synchronous, timing, Distortion, Bits, band, WPM
• MCQ in Data Interface standards, Data input/output devices
• MCQ in Digital Transmission on analog channel, Modulation-demodulation schemes parameters
• MCQ in Circuit conditioning, Modem Applications
• MCQ in Serial and Parallel Transmission

Continue Practice Exam Test Questions Part 10 of the Series

⇐ MCQ in Digital and Data Communication Networks Part 9 | ECE Board

Choose the letter of the best answer in each questions.

451. Alternate Mark Inversion (AMI) is also known as

A. pseudo ternary coding

B. manchester coding

C. polar nrz format

D. none of the above

452. The process of coding multiplexer output into electrical pulses or waveforms for transmission is called

A. line coding

B. amplitude modulation

C. fsk

D. filtering

453. Eye pattern is

A. is used to study isi

B. may be seen on cro

C. resembles the shape of human eye

D. all of the above

454. The criterion used for pulse shaping to avoid ISI is

A. nyquist criterion

B. quantization

C. sample and hold

D. pll

455. TDM is

A. analog multiplexing

B. digital multiplexing

C. a to d converter

D. both a & b

456. Random variables give relationship between ______.

A. two random events

B. probability of occurrence of two random events

C. random event and a real number

D. random event and its probability of occurrence

457. The distribution function of random variable is

A. p(x less than or equal to x)

B. p(x greater than or equal to x)

C. p(x less than x)

D. p(x greater than x)

458. The value of the probability density function of random variable is

A. positive function

B. negative function

C. zero

D. one

459. Which gives the measure of randomness of the random variable?

A. mean

B. variance

C. standard variance

D. pdf

460. Random process is a function of

A. random event and time

B. random event and frequency

C. random event and real number

D. none of the mentioned

461. A random process is called as stationary in strict sense if

A. its statistics vary with shift in time origin

B. its statistics does not vary with shift in time origin

C. its autocorrelation vary with shift in time

D. its autocorrelation does not vary with shift in time

462. For a stationary process, autocorrelation function depends on

A. time

B. time difference

C. does not depend on time

D. none of the mentioned

463. The autocorrelation function is maximum at

A. origin

B. infinity

C. origin & infinity

D. none of the mentioned

464. Standard deviation is ______.

A. rms value of dc

B. rms value or ac

C. either ac or dc

D. neither dc nor ac

465. The average power of white noise is

A. zero

B. unity

C. infinity

D. between zero and one

466. The distribution function of -(infinity) and (infinity) is ______.

A. 0 and 1

B. 1 and 0

C. both 0

D. both 1

467. White noise has mean and ______ variance.

A. zero and zero

B. finite and zero

C. zero and finite

D. one and zero

468. Power spectral density function is a?

A. real and even function

B. non negative function

C. periodic

D. all of the mentioned

469. Energy spectral density defines

A. signal energy per unit area

B. signal energy per unit bandwidth

C. signal power per unit area

D. signal power per unit bandwidth

470. Power spectrum describes distribution of under frequency domain.

A. mean

B. variance

C. gaussian

D. none of the mentioned

471. How can power spectral density of non-periodic signal be calculated?

A. by integrating

B. by truncating

C. by converting to periodic

D. none of the mentioned

472. What is Wiener-Khinchin theorem?

A. spectral density and auto-covariance makes a Fourier transform pair

B. spectral density and auto-correlation makes a Fourier transform pair

C. spectral density and variance makes a Fourier transform pair

D. none of the mentioned

473. According to Parseval’s theorem the energy spectral density curve is equal to?

A. area under magnitude of the signal

B. area under square of the magnitude of the signal

C. area under square root of magnitude of the signal

D. none of the mentioned

474. Autocorrelation is a function which matches

A. two same signals

B. two different signal

C. one signal with its delayed version

D. none of the mentioned

475. Autocorrelation is a function of

A. time

B. frequency

C. time difference

D. frequency difference

476. Autocorrelation is maximum at

A. unity

B. origin

C. infinite point

D. none of the mentioned

477. Autocorrelation function of periodic signal is equal to

A. energy of the signal

B. power of the signal

C. its area in frequency domain

D. none of the mentioned

478. Autocorrelation function of white noise will have?

A. strong peak

B. infinite peak

C. weak peak

D. none of the mentioned

479. Thermal noise in the communication system due to thermal electrons

A. can be eliminated

B. cannot be eliminated

C. can be avoided up to some extent

D. none of the mentioned

480. White noise has power spectral density.

A. constant

B. variable

C. constant & variable

D. none of the mentioned

481. The average noise power of white noise is

A. 0

B. infinity

C. 1

D. none of the mentioned

482. The channel may be affected by

A. thermal noise

B. interference from other signals

C. thermal noise & interference from other signals

D. none of the mentioned

483. In Random Variable we have

A. sample space

B. sample points

C. sample space & sample points

D. none of above

484. In Random Process we have

A. sample function

B. ensemble of sample function

C. sample space & sample points

D. sample function & ensemble of sample function

485. The detection method where carrier’s phase is given importance is called as

A. coherent detection

B. non coherent detection

C. coherent detection & non coherent detection

D. none of the mentioned

486. The coherent modulation techniques are

A. psk

B. fsk

C. ask

D. all of the mentioned

487. The real part of a sinusoid carrier wave is called as

A. inphase

B. quadrature

C. inphase & quadrature

D. none of the mentioned

488. The FSK signal which has a gentle shift from one frequency level to another is called as

A. differential psk

B. continuous psk

C. differential & continuous psk

D. none of the mentioned

489. Which modulation scheme is also called as on-off keying method?

A. ask

B. fsk

C. psk

D. gmsk

490. In differential PSK the date is

A. encoded differentially

B. decoded differentially

C. encoded & decoded differentially

D. none of the mentioned

491. Envelope detector consists of

A. rectifier and high pass filter

B. rectifier and low pass filter

C. amplifier and low pass filter

D. amplifier and high pass filter

492. M-ary signaling produces error performance with orthogonal signaling and error performance with multiple phase signaling.

A. degraded, improved

B. improved, degraded

C. improved, improved

D. degraded, degraded

493. Which is more vulnerable to noise?

A. 2-ary system

B. 4-ary system

C. binary system

D. none of the mentioned

494. In which system, bit stream is portioned into even and odd stream?

A. bpsk

B. msk

C. qpsk

D. fsk

495. The error performance of MPSK as M or k increases.

A. increases

B. decreases

C. stays constant

D. none of the mentioned

496. In MPSK adding new signals make it vulnerable to noise and in MFSK ______ make it vulnerable.

A. does, does not

B. does not, does

C. does, does

D. does not, does not

497. In orthogonal signalling with symbols containing more number of bits we need power.

A. more

B. less

C. double

D. none of the mentioned

498. Energy per symbol Es is given as

A. es=eb(log₂m)

B. es=eb/(log₂m)

C. es=2eb(log₂m)

D. es=eb/2(log₂m)

499. The relation between the probability of bit error and probability of symbol error in M-ary orthogonal signalling is

A. m/m-1

B. 2m/m-1

C. (m/2)/m-1

D. m/m+1

500. Performance of BFSK signal is than BPSK.

A. 3 dB worse

B. 3 dB better

C. 6 dB worse

D. 6 dB better

Questions and Answers in Digital and Data Communication Networks Series

Following is the list of multiple choice questions in this brand new series:

Complete List of MCQ in Communications Engineering per topic