MCQOPTIONS
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MCQOPTIONS
This section includes 49 Mcqs, each offering curated multiple-choice questions to sharpen your Electrical Engineering knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
The time interval over which the received signal may be sampled without error may be explained by |
| A. | width of eye opening of eye pattern |
| B. | rate of closure of eye of eye pattern |
| C. | height of the eye opening of eye pattern |
| D. | all of the above |
| Answer» B. rate of closure of eye of eye pattern | |
| 2. |
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 |
| Answer» D. none of the above | |
| 3. |
In On-Off keying, the carrier signal is transmitted with signal value 1 and 0 indicates |
| A. | no carrier |
| B. | half the carrier amplitude |
| C. | amplitude of modulating signal |
| D. | none of the above |
| Answer» B. half the carrier amplitude | |
| 4. |
The maximum synchronizing capability in coding techniques is present in |
| A. | manchester format |
| B. | polar nrz |
| C. | polar rz |
| D. | polar quaternary nrz |
| Answer» B. polar nrz | |
| 5. |
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 |
| Answer» B. white noise | |
| 6. |
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 |
| Answer» B. amplitude modulation | |
| 7. |
In Binary Phase Shift Keying system, the binary symbols 1 and 0 are represented by carrier with phase shift of |
| A. | /2 |
| B. | |
| C. | 2 |
| D. | 0 |
| Answer» C. 2 | |
| 8. |
The probability of error of DPSK is ______________ than that of BPSK. |
| A. | higher |
| B. | lower |
| C. | same |
| D. | not predictable |
| Answer» B. lower | |
| 9. |
The BPSK signal has +V volts and -V volts respectively to represent |
| A. | 1 and 0 logic levels |
| B. | 11 and 00 logic levels |
| C. | 10 and 01 logic levels |
| D. | 00 and 11 logic levels |
| Answer» B. 11 and 00 logic levels | |
| 10. |
BPSK system modulates at the rate of |
| A. | 1 bit/ symbol |
| B. | 2 bit/ symbol |
| C. | 4 bit/ symbol |
| D. | none of the above |
| Answer» B. 2 bit/ symbol | |
| 11. |
Coherent detection of binary ASK signal requires |
| A. | phase synchronization |
| B. | timing synchronization |
| C. | amplitude synchronization |
| D. | both a and b |
| Answer» E. | |
| 12. |
ASK modulated signal has the bandwidth |
| A. | same as the bandwidth of baseband signal |
| B. | half the bandwidth of baseband signal |
| C. | double the bandwidth of baseband signal |
| D. | none of the above |
| Answer» B. half the bandwidth of baseband signal | |
| 13. |
Orthonormal set is a set of all vectors that are |
| A. | mutually orthonormal and are of unit length |
| B. | mutually orthonormal and of null length |
| C. | both a & b |
| D. | none of the above |
| Answer» B. mutually orthonormal and of null length | |
| 14. |
For two vectors to be orthonormal, the vectors are also said to be orthogonal. The reverse of the same |
| A. | is true |
| B. | is not true |
| C. | is not predictable |
| D. | none of the above |
| Answer» C. is not predictable | |
| 15. |
Zero forced equalizers are used for |
| A. | reducing isi to zero |
| B. | sampling |
| C. | quantization |
| D. | none of the abov |
| Answer» B. sampling | |
| 16. |
Equalization in digital communication |
| A. | reduces inter symbol interference |
| B. | removes distortion caused due to channel |
| C. | is done using linear filters |
| D. | all of the above |
| Answer» E. | |
| 17. |
The difficulty in achieving the Nyquist criterion for system design is |
| A. | there are abrupt transitions obtained at edges of the bands |
| B. | bandwidth criterion is not easily achieved |
| C. | filters are not available |
| D. | none of the above |
| Answer» B. bandwidth criterion is not easily achieved | |
| 18. |
The Nyquist theorem is |
| A. | relates the conditions in time domain and frequency domain |
| B. | helps in quantization |
| C. | limits the bandwidth requirement |
| D. | both a and c |
| Answer» E. | |
| 19. |
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 |
| Answer» E. | |
| 20. |
Nyquist criterion helps in |
| A. | transmitting the signal without isi |
| B. | reduction in transmission bandwidth |
| C. | increase in transmission bandwidth |
| D. | both a and b |
| Answer» E. | |
| 21. |
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 |
| Answer» E. | |
| 22. |
Timing jitter is |
| A. | change in amplitude |
| B. | change in frequency |
| C. | deviation in location of the pulses |
| D. | all of the above |
| Answer» D. all of the above | |
| 23. |
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 |
| Answer» E. | |
| 24. |
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 |
| Answer» B. the integrated product of two different code words is one | |
| 25. |
Matched filter may be optimally used only for |
| A. | gaussian noise |
| B. | transit time noise |
| C. | flicker |
| D. | all of the above |
| Answer» B. transit time noise | |
| 26. |
T1 carrier system is used |
| A. | for pcm voice transmission |
| B. | for delta modulation |
| C. | for frequency modulated signals |
| D. | none of the above |
| Answer» B. for delta modulation | |
| 27. |
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 |
| Answer» D. 5.6 megabits per second | |
| 28. |
The number of voice channels that can be accommodated for transmission in T1 carrier system is |
| A. | 24 |
| B. | 32 |
| C. | 56 |
| D. | 64 |
| Answer» B. 32 | |
| 29. |
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 |
| Answer» C. quantization error remains same | |
| 30. |
The digital modulation scheme in which the step size is not fixed is |
| A. | delta modulation |
| B. | adaptive delta modulation |
| C. | dpcm |
| D. | pcm |
| Answer» C. dpcm | |
| 31. |
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 |
| Answer» D. pam | |
| 32. |
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 |
| Answer» D. peak value/ 2rms value | |
| 33. |
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 |
| Answer» C. there is interference from the adjacent channel | |
| 34. |
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 |
| Answer» E. | |
| 35. |
The noise that affects PCM |
| A. | transmission noise |
| B. | quantizing noise |
| C. | transit noise |
| D. | both a and b are correct |
| Answer» E. | |
| 36. |
DPCM suffers from |
| A. | slope over load distortion |
| B. | quantization noise |
| C. | both a & b |
| D. | none of the above |
| Answer» D. none of the above | |
| 37. |
In Differential Pulse Code Modulation techniques, the decoding is performed by |
| A. | accumulator |
| B. | sampler |
| C. | pll |
| D. | quantizer |
| Answer» B. sampler | |
| 38. |
In digital transmission, the modulation technique that requires minimum bandwidth is |
| A. | delta modulation |
| B. | pcm |
| C. | dpcm |
| D. | pam |
| Answer» B. pcm | |
| 39. |
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 |
| Answer» E. | |
| 40. |
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 |
| Answer» B. n times the modulating frequency | |
| 41. |
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 |
| Answer» E. | |
| 42. |
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 |
| Answer» B. bw ≤ vfm | |
| 43. |
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 |
| Answer» B. very high noise | |
| 44. |
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 |
| Answer» B. quantizing, encoding, sampling | |
| 45. |
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 |
| Answer» E. | |
| 46. |
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 |
| Answer» E. | |
| 47. |
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 |
| Answer» B. logarithmic in nature | |
| 48. |
The process of converting the analog sample into discrete form is called |
| A. | modulation |
| B. | multiplexing |
| C. | quantization |
| D. | sampling |
| Answer» D. sampling | |
| 49. |
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 |
| Answer» E. | |