MCQ in Digital and Data Communication Networks Part 8 | ECE Board

This is the Multiple Choice Questions Part 8 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 8 of the Series

⇐ MCQ in Digital and Data Communication Networks Part 7 | ECE Board

Choose the letter of the best answer in each questions.

351. In uniform quantization process

A. the step size remains same

B. step size varies according to the values of the input signal

C. the quantizer has linear characteristics

D. both a and c are correct

352. The process of converting the analog sample into discrete form is called

A. modulation

B. multiplexing

C. quantization

D. sampling

353. The characteristics of compressor in μ-law companding are

A. continuous in nature

B. logarithmic in nature

C. linear in nature

D. discrete in nature

354. The modulation techniques used to convert analog signal into digital signal are

A. pulse code modulation

B. delta modulation

C. adaptive delta modulation

D. all of the above

355. The sequence of operations in which PCM is done is

A. sampling, quantizing, encoding

B. quantizing, encoding, sampling

C. quantizing, sampling, encoding

D. none of the above

356. In PCM, the parameter varied in accordance with the amplitude of the modulating signal is

A. amplitude

B. frequency

C. phase

D. none of the above

357. One of the disadvantages of PCM is

A. it requires large bandwidth

B. very high noise

C. cannot be decoded easily

D. all of the above

358. The expression for bandwidth BW of a PCM system, where v is the number of bits per sample and FM is the modulating frequency, is given by

A. bw ≥ vfm

B. bw ≤ vfm

C. bw ≥ 2 vfm

D. bw ≥ 1/2 vfm

359. The error probability of a PCM is

A. calculated using noise and inter symbol interference

B. gaussian noise + error component due to inter symbol interference

C. calculated using power spectral density

D. all of the above

360. In Delta modulation,

A. one bit per sample is transmitted

B. all the coded bits used for sampling are transmitted

C. the step size is fixed

D. both a and c are correct

361. In digital transmission, the modulation technique that requires minimum bandwidth is

A. delta modulation

B. pcm

C. dpcm

D. pam

362. In Delta Modulation, the bit rate is

A. n times the sampling frequency

B. n times the modulating frequency

C. n times the Nyquist criteria

D. none of the above

363. In Differential Pulse Code Modulation techniques, the decoding is performed by

A. accumulator

B. sampler

C. PLL

D. quantizer

364. DPCM suffers from

A. slope overload distortion

B. quantization noise

C. both a & b

D. none of the above

365. The noise that affects PCM

A. transmission noise

B. quantizing noise

C. transit noise

D. both a and b are correct

366. The factors that cause quantizing error in delta modulation are

A. slope overload distortion

B. granular noise

C. white noise

D. both a and b are correct

367. Granular noise occurs when

A. step size is too small

B. step size is too large

C. there is interference from the adjacent channel

D. bandwidth is too large

368. The crest factor of a waveform is given as –

A. 2peak value/ rms value

B. rms value / peak value

C. peak value/ rms value

D. peak value/ 2rms value

369. The digital modulation technique in which the step size is varied according to the variation in the slope of the input is called

A. delta modulation

B. PCM

C. adaptive delta modulation

D. pam

370. The digital modulation scheme in which the step size is not fixed is

A. delta modulation

B. adaptive delta modulation

C. dpcm

D. pcm

371. In Adaptive Delta Modulation, the slope error reduces and

A. quantization error decreases

B. quantization error increases

C. quantization error remains same

D. none of the above

372. The number of voice channels that can be accommodated for transmission in T1 carrier system is

A. 24

B. 32

C. 56

D. 64

373. The maximum data transmission rate in T1 carrier system is

A. 2.6 megabits per second

B. 1000 megabits per second

C. 1.544 megabits per second

D. 5.6 megabits per second

374. T1 carrier system is used

A. for pcm voice transmission

B. for delta modulation

C. for frequency modulated signals

D. none of the above

375. Matched filter may be optimally used only for

A. gaussian noise

B. transit time noise

C. flicker

D. all of the above

376. Matched filters may be used

A. to estimate the frequency of the received signal

B. in parameter estimation problems

C. to estimate the distance of the object

D. all of the above

377. 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

378. For a line code, the transmission bandwidth must be

A. maximum possible

B. as small as possible

C. depends on the signal

D. none of the above

379. Regenerative repeaters are used for

A. eliminating noise

B. reconstruction of signals

C. transmission over long distances

D. all of the above

380. Scrambling of data is

A. removing long strings of 1’s and 0’s

B. exchanging of data

C. transmission of digital data

D. all of the above

381. In polar RZ format for coding, symbol ‘0’ is represented by

A. zero voltage

B. negative voltage

C. pulse is transmitted for half the duration

D. both b and c are correct

382. Polar coding is a technique in which

A. 1 is transmitted by a positive pulse and 0 is transmitted by negative pulse

B. 1 is transmitted by a positive pulse and 0 is transmitted by zero volts

C. both a & b

D. none of the above

383. The polarities in NRZ format use

A. complete pulse duration

B. half duration

C. both positive as well as negative value

D. each pulse is used for twice the duration

384. The format in which the positive half interval pulse is followed by a negative half interval pulse for transmission of ‘1’ is

A. polar nrz format

B. bipolar nrz format

C. manchester format

D. none of the above

385. The maximum synchronizing capability in coding techniques is present in

A. manchester format

B. polar nrz

C. polar rz

D. polar quaternary nrz

386. The advantage of using Manchester format of coding is

A. power saving

B. polarity sense at the receiver

C. noise immunity

D. none of the above

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

A. pseudo ternary coding

B. manchester coding

C. polar nrz format

D. none of the above

388. In DPSK technique, the technique used to encode bits is

A. ami

B. differential code

C. uni polar rz format

D. manchester format

389. Overhead bits are

A. framing and synchronizing bits

B. data due to noise

C. encoded bits

D. none of the above

390. ISI may be removed by using

A. differential coding

B. manchester coding

C. polar nrz

D. none of the above

391. Timing jitter is

A. change in amplitude

B. change in frequency

C. deviation in location of the pulses

D. all of the above

392. Probability density function defines

A. amplitudes of random noise

B. density of signal

C. probability of error

D. all of the above

393. Impulse noise is caused due to

A. switching transients

B. lightening strikes

C. power line load switching

D. all of the above

394. In coherent detection of signals,

A. local carrier is generated

B. carrier of frequency and phase as same as transmitted carrier is generated

C. the carrier is in synchronization with modulated carrier

D. all of the above

395. Synchronization of signals is done using

A. pilot clock

B. extracting timing information from the received signal

C. transmitter and receiver connected to master timing source

D. all of the above

396. Orthogonality of two codes means

A. the integrated product of two different code words is zero

B. the integrated product of two different code words is one

C. the integrated product of two same code words is zero

D. none of the above

397. In Alternate Mark Inversion (AMI) is

A. 0 is encoded as positive pulse and 1 is encoded as negative pulse

B. 0 is encoded as no pulse and 1 is encoded as negative pulse

C. 0 is encoded as negative pulse and 1 is encoded as positive pulse

D. 0 is encoded as no pulse and 1 is encoded as positive or negative pulse

398. Advantages of using AMI

A. needs least power as due to opposite polarity

B. prevents build-up of dc

C. may be used for longer distance

D. all of the above

399. The interference caused by the adjacent pulses in digital transmission is called

A. inter symbol interference

B. white noise

C. image frequency interference

D. transit time noise

400. 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

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