MCQOPTIONS
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MCQOPTIONS
This section includes 657 Mcqs, each offering curated multiple-choice questions to sharpen your Testing Subject knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
PSK stands for Pulse Shift Keying. |
| A. | true |
| B. | false |
| Answer» C. | |
| 2. |
Which term is used when signals move from one line to another? |
| A. | path switching |
| B. | space switching |
| C. | line switching |
| D. | cross-point switching |
| Answer» C. line switching | |
| 3. |
TDMA stands for |
| A. | time division multiple access |
| B. | time domain multiple access |
| C. | time division mutual access |
| D. | time domain mutual access |
| Answer» B. time domain multiple access | |
| 4. |
The polarization of plane waves received from satellite is changed by |
| A. | faraday rotation |
| B. | gamma rays |
| C. | helical rotation |
| D. | distance travelled |
| Answer» B. gamma rays | |
| 5. |
What is the full form of ERP? |
| A. | effective radiated power |
| B. | effective reflected power |
| C. | equivalent radiated power |
| D. | equivalent reflected power |
| Answer» B. effective reflected power | |
| 6. |
What is the input impedance to a lossless antenna, at resonance? |
| A. | infinite |
| B. | 0 |
| C. | resistive |
| D. | capacitive |
| Answer» D. capacitive | |
| 7. |
When an antenna radiates more energy in one direction than in other directions, it is called |
| A. | selectivity |
| B. | directivity |
| C. | active antenna |
| D. | resonance |
| Answer» C. active antenna | |
| 8. |
Measured on the ground, the field strength of a horizontally polarized half wave dipole antenna is strongest |
| A. | in one direction |
| B. | in two directions |
| C. | depends on the number of elements |
| D. | depends on the shape of antenna |
| Answer» C. depends on the number of elements | |
| 9. |
What is the other name for half-wave dipole antenna? |
| A. | helical antenna |
| B. | isotropic antenna |
| C. | hertz antenna |
| D. | maxwell antenna |
| Answer» D. maxwell antenna | |
| 10. |
The real part of an antenna’s input impedance is due to |
| A. | swr |
| B. | radiated signal |
| C. | reflected signal |
| D. | refracted signal |
| Answer» C. reflected signal | |
| 11. |
Cepstrum vocoder uses |
| A. | wavelet transform |
| B. | inverse wavelet transform |
| C. | cosine transform |
| D. | inverse fourier transform |
| Answer» E. | |
| 12. |
Formant vocoders use large number of control signals. |
| A. | true |
| B. | false |
| Answer» C. | |
| 13. |
                 is often called the formant of the speech signal. |
| A. | pitch frequency |
| B. | voice pitch |
| C. | pole frequency |
| D. | central frequency |
| Answer» D. central frequency | |
| 14. |
Channel vocoders are the time domain vocoders. |
| A. | true |
| B. | false |
| Answer» C. | |
| 15. |
Which of the following pronunciations lead to voiced sound? |
| A. | ‘f’ |
| B. | ‘s’ |
| C. | ‘sh’ |
| D. | ‘m’ |
| Answer» E. | |
| 16. |
Which of the following is not a vocoding system? |
| A. | linear predictive coder |
| B. | channel vocoder |
| C. | waveform coder |
| D. | formant vocoder |
| Answer» D. formant vocoder | |
| 17. |
6 CHANNEL VOCODER |
| A. | true |
| B. | false |
| Answer» C. | |
| 18. |
Vocoders                      the voice at the receiver. |
| A. | analyse |
| B. | synthesize |
| C. | modulate |
| D. | evaluate |
| Answer» C. modulate | |
| 19. |
Vocoders analyse the speech signals at |
| A. | transmitter |
| B. | receiver |
| C. | channel |
| D. | if filter |
| Answer» B. receiver | |
| 20. |
Adaptive DPCM is used to |
| A. | increase bandwidth |
| B. | decrease bandwidth |
| C. | increase snr |
| D. | none of the mentioned |
| Answer» C. increase snr | |
| 21. |
Delta modulation uses            bits per sample. |
| A. | one |
| B. | two |
| C. | four |
| D. | eight |
| Answer» B. two | |
| 22. |
Sample resolution for LPCM Â Â Â Â Â Â Â Â Â bits per sample. |
| A. | 8 |
| B. | 16 |
| C. | 24 |
| D. | all of the mentioned |
| Answer» E. | |
| 23. |
In PCM the samples are dependent on |
| A. | time |
| B. | frequency |
| C. | quanization leavel |
| D. | interval between quantization level |
| Answer» B. frequency | |
| 24. |
DPCM encodes the PCM values based on |
| A. | quantization level |
| B. | difference between the current and predicted value |
| C. | interval between levels |
| D. | none of the mentioned |
| Answer» C. interval between levels | |
| 25. |
Choosing a discrete value that is near but not exactly at the analog signal level leads to |
| A. | pcm error |
| B. | quantization error |
| C. | pam error |
| D. | sampling error |
| Answer» C. pam error | |
| 26. |
What is bit depth? |
| A. | number of quantization level |
| B. | interval between two quantization levels |
| C. | number of possible digital values to represent each sample |
| D. | none of the mentioned |
| Answer» D. none of the mentioned | |
| 27. |
In PCM encoding, quantization level varies as a function of |
| A. | frequency |
| B. | amplitude |
| C. | square of frequency |
| D. | square of amplitude |
| Answer» C. square of frequency | |
| 28. |
The length of the code-word obtained by encoding quantized sample is equal to |
| A. | l=log(to the base 2)l |
| B. | l=log(to the base 10)l |
| C. | l=2log(to the base 2)l |
| D. | l=log(to the base 2)l/2 |
| Answer» B. l=log(to the base 10)l | |
| 29. |
The signals which are obtained by encoding each quantized signal into a digital word is called as |
| A. | pam signal |
| B. | pcm signal |
| C. | fm signal |
| D. | sampling and quantization |
| Answer» C. fm signal | |
| 30. |
In which waveform logic 1 is represented by equal amplitude alternating pulses? |
| A. | unipolar rz |
| B. | bipolar rz |
| C. | rz-ami |
| D. | manchester coding |
| Answer» D. manchester coding | |
| 31. |
In which waveform logic 1 and logic 0 are represented by opposite one half bit wide pulses? |
| A. | unipolar rz |
| B. | bipolar rz |
| C. | rz-ami |
| D. | manchester coding |
| Answer» C. rz-ami | |
| 32. |
Phase encoded group consists of |
| A. | manchester coding |
| B. | bi-phase-mark |
| C. | miller coding |
| D. | all of the mentioned |
| Answer» E. | |
| 33. |
The return to zero waveform consists of |
| A. | unipolar rz |
| B. | bipolar rz |
| C. | rz-ami |
| D. | all of the mentioned |
| Answer» E. | |
| 34. |
In which waveform logic 1 is represented by half bit wide pulse and logic 0 is represented by absence of pulse? |
| A. | unipolar rz |
| B. | bipolar rz |
| C. | rz-ami |
| D. | manchester coding |
| Answer» B. bipolar rz | |
| 35. |
NRZ-S is complement of |
| A. | nrz-l |
| B. | nrz-m |
| C. | nrz-l & nrz-m |
| D. | none of the mentioned |
| Answer» C. nrz-l & nrz-m | |
| 36. |
Which method is preferred in magnetic tape recording? |
| A. | nrz-l |
| B. | nrz-m |
| C. | nrz-s |
| D. | none of the mentioned |
| Answer» C. nrz-s | |
| 37. |
Which method is called as differential encoding? |
| A. | nrz-l |
| B. | nrz-m |
| C. | nrz-s |
| D. | none of the mentioned |
| Answer» C. nrz-s | |
| 38. |
Which type is used and preferred in digital logic circuits? |
| A. | nrz-l |
| B. | nrz-m |
| C. | nrz-s |
| D. | none of the mentioned |
| Answer» B. nrz-m | |
| 39. |
Examples of PCM waveforms are |
| A. | non return to zero |
| B. | phase encoded |
| C. | multilevel binary |
| D. | all of the mentioned |
| Answer» E. | |
| 40. |
When pulse code modulation is applied to non binary symbols we obtain waveform called as |
| A. | pcm |
| B. | pam |
| C. | m-ary |
| D. | line codes |
| Answer» D. line codes | |
| 41. |
Which waveforms are also called as line codes? |
| A. | pcm |
| B. | pam |
| C. | fm |
| D. | am |
| Answer» B. pam | |
| 42. |
TDM requires |
| A. | constant data transmission |
| B. | transmission of data samples |
| C. | transmission of data at random |
| D. | transmission of data of only one measured |
| Answer» C. transmission of data at random | |
| 43. |
In an ideal TDM system, the cross correlation between two users of the system is |
| A. | 1 |
| B. | 0 |
| C. | infinity |
| D. | -1 |
| Answer» C. infinity | |
| 44. |
TDM is less immune to cross-talk in channel than FDM. |
| A. | true |
| B. | false |
| Answer» C. | |
| 45. |
A PWM signal can be generated by |
| A. | an astable multi vibrator |
| B. | a monostable multi vibrator |
| C. | integrating a ppm signal |
| D. | differentiating a ppm signal |
| Answer» C. integrating a ppm signal | |
| 46. |
The use of non uniform quantization leads to |
| A. | reduction in transmission bandwidth |
| B. | increase in maximum snr |
| C. | increase in snr for low level signals |
| D. | simplification of quantization process |
| Answer» D. simplification of quantization process | |
| 47. |
Coherent demodulation of FSK signal can be performed using |
| A. | matched filter |
| B. | bpf and envelope detectors |
| C. | discriminator |
| D. | none of the mentioned |
| Answer» B. bpf and envelope detectors | |
| 48. |
A PAM signal can be detected using |
| A. | low pass filter |
| B. | high pass filter |
| C. | band pass filter |
| D. | all pass filter |
| Answer» B. high pass filter | |
| 49. |
In a delta modulation system, granular noise occurs when the |
| A. | modulating signal increases rapidly |
| B. | pulse rate decreases |
| C. | pulse amplitude decreases |
| D. | modulating signal remains constant |
| Answer» E. | |
| 50. |
Flat top sampling of low pass signals |
| A. | gives rise to aperture effect |
| B. | implies over sampling |
| C. | leads to aliasing |
| D. | introduces delay distortion |
| Answer» B. implies over sampling | |