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. |
is equal to width of main spectral lobe. |
| A. | null to null bandwidth |
| B. | half power bandwidth |
| C. | 3 db bandwidth |
| D. | absolute bandwidth |
| Answer» B. half power bandwidth | |
| 2. |
The performance of modulation scheme is not measured in terms of |
| A. | power efficiency |
| B. | bandwidth efficiency |
| C. | cost and complexity |
| D. | transmitted power |
| Answer» E. | |
| 3. |
What do you understand by the term “carrier” in modulation? |
| A. | voltage to be transmitted |
| B. | resultant wave |
| C. | voltage for which amplitude, phase or frequency can be varied |
| D. | voltage for which amplitude, phase or frequency remains constant |
| Answer» D. voltage for which amplitude, phase or frequency remains constant | |
| 4. |
AM demodulation technique can be divided into and demodulation. |
| A. | direct, indirect |
| B. | slope detector, zero crossing |
| C. | coherent, noncoherent |
| D. | quadrature detection, coherent detection |
| Answer» D. quadrature detection, coherent detection | |
| 5. |
If the peak message signal amplitude is half the peak amplitude of the carrier signal, the signal is modulated. |
| A. | 100% |
| B. | 2% |
| C. | 50% |
| D. | 70% |
| Answer» D. 70% | |
| 6. |
CT2 is analog version of first generation cordless telephones. |
| A. | true |
| B. | false |
| Answer» C. | |
| 7. |
CT2 was the first generation of cordless telephones. |
| A. | true |
| B. | false |
| Answer» C. | |
| 8. |
                     are used to resolve and combine multipath components. |
| A. | equalizer |
| B. | registers |
| C. | rake receiver |
| D. | frequency divider |
| Answer» D. frequency divider | |
| 9. |
IS-95 is specified for reverse link operation in                    band. |
| A. | 869-894 mhz |
| B. | 849-894 mhz |
| C. | 849-869 mhz |
| D. | 824-849 mhz |
| Answer» E. | |
| 10. |
IS-95 uses same modulation technique for forward and reverse channel. |
| A. | true |
| B. | false |
| Answer» C. | |
| 11. |
User data in IS-95 is spread to a channel chip rate of |
| A. | 1.2288 mchip/s |
| B. | 9.6 mchip/s |
| C. | 12.288 mchip/s |
| D. | 0.96 mchip/s |
| Answer» B. 9.6 mchip/s | |
| 12. |
Which of the following is used by IS-95? |
| A. | dsss |
| B. | fhss |
| C. | thss |
| D. | hybrid |
| Answer» B. fhss | |
| 13. |
IS-95 was not compatible with existing AMPS frequency band. |
| A. | true |
| B. | false |
| Answer» C. | |
| 14. |
US digital cellular system based on CDMA was standardized as |
| A. | is-54 |
| B. | is-136 |
| C. | is-95 |
| D. | is-76 |
| Answer» D. is-76 | |
| 15. |
What is the time duration of a bit if data is transmitted at 270.833 kbps in the channel? |
| A. | 270.833 s |
| B. | 3 μs |
| C. | 3.692 μs |
| D. | 3.692 s |
| Answer» D. 3.692 s | |
| 16. |
Which of the following is not true for TDMA? |
| A. | single carrier frequency for single user |
| B. | discontinuous data transmission |
| C. | no requirement of duplexers |
| D. | high transmission rates |
| Answer» B. discontinuous data transmission | |
| 17. |
TDMA allocates a single time per frame to different users. |
| A. | true |
| B. | false |
| Answer» C. | |
| 18. |
Because of                transmissions in TDMA, the handoff process in |
| A. | continuous, complex |
| B. | continuous, simple |
| C. | discontinuous, complex |
| D. | discontinuous, simple |
| Answer» E. | |
| 19. |
                       of TDMA system is a measure of the percentage of transmitted data that contains information as opposed to providing overhead for the access scheme. |
| A. | efficiency |
| B. | figure of merit |
| C. | signal to noise ratio |
| D. | mean |
| Answer» B. figure of merit | |
| 20. |
                     synchronization overhead is required in TDMA due to                transmission. |
| A. | high, burst |
| B. | high, continuous |
| C. | low, burst |
| D. | no, burst |
| Answer» B. high, continuous | |
| 21. |
                     are utilized to allow synchronization of the receivers between different slots and frames. |
| A. | preamble |
| B. | data |
| C. | guard bits |
| D. | trail bits |
| Answer» D. trail bits | |
| 22. |
                     is based on FDMA/FDD. |
| A. | gsm |
| B. | w-cdma |
| C. | cordless telephone |
| D. | amps |
| Answer» E. | |
| 23. |
TDMA systems transmit in a continuous way. |
| A. | true |
| B. | false |
| Answer» C. | |
| 24. |
                     is undesired RF radiation. |
| A. | intermodulation frequency |
| B. | intermediate frequency |
| C. | instantaneous frequency |
| D. | instrumental frequency |
| Answer» B. intermediate frequency | |
| 25. |
In US AMPS, 416 channels are allocated to various operators with 10 kHz guard band and channel between them is 30 kHz. What is the spectrum allocation given to each operator? |
| A. | 12.5 khz |
| B. | 30 khz |
| C. | 12.5 mhz |
| D. | 30 mhz |
| Answer» D. 30 mhz | |
| 26. |
Which of the following is not true for FDMA systems as compared to TDMA systems? |
| A. | low complexity |
| B. | lower cell site system cost |
| C. | tight rf filtering |
| D. | narrow bandwidth |
| Answer» C. tight rf filtering | |
| 27. |
The bandwidth of FDMA channel is |
| A. | wide |
| B. | narrow |
| C. | large |
| D. | zero |
| Answer» C. large | |
| 28. |
If the FDMA channel is not in use, it can be used by other users. |
| A. | true |
| B. | false |
| Answer» C. | |
| 29. |
Frequency division multiple access (FDMA) assigns              channels to                users. |
| A. | individual, individual |
| B. | many, individual |
| C. | individual, many |
| D. | many, many |
| Answer» B. many, individual | |
| 30. |
Which duration is shorter? |
| A. | hop duration |
| B. | symbol duration |
| C. | chip duration |
| D. | none of the mentioned |
| Answer» B. symbol duration | |
| 31. |
Fast frequency hopping is |
| A. | several modulations per hop |
| B. | several modulations per symbol |
| C. | several symbols per modulation |
| D. | none of the mentioned |
| Answer» E. | |
| 32. |
Slow frequency hopping is |
| A. | several hops per modulation |
| B. | several modulations per hop |
| C. | several symbols per modulation |
| D. | none of the mentioned |
| Answer» C. several symbols per modulation | |
| 33. |
Chips are the |
| A. | repeated symbols |
| B. | non repeated symbols |
| C. | smallest length symbols |
| D. | none of the mentioned |
| Answer» B. non repeated symbols | |
| 34. |
Robustness gives the inability of a signal to withstand the impairments. |
| A. | true |
| B. | false |
| Answer» C. | |
| 35. |
Which system allows larger processing gain? |
| A. | direct sequence |
| B. | frequency hopping |
| C. | direct sequence & frequency hopping |
| D. | none of the mentioned |
| Answer» C. direct sequence & frequency hopping | |
| 36. |
Which type of demodulator is used in the frequency hopping technique? |
| A. | coherent |
| B. | non coherent |
| C. | coherent & non coherent |
| D. | none of the mentioned |
| Answer» C. coherent & non coherent | |
| 37. |
The minimum spacing between consecutive hop positions gives the |
| A. | minimum number of chips necessary |
| B. | maximum number of chips necessary |
| C. | chip rate |
| D. | none of the mentioned |
| Answer» B. maximum number of chips necessary | |
| 38. |
In which technique is phase coherence hard to maintain? |
| A. | direct sequence |
| B. | frequency hopping |
| C. | direct sequence & frequency hopping |
| D. | none of the mentioned |
| Answer» C. direct sequence & frequency hopping | |
| 39. |
The processing gain is given as              modulation scheme. |
| A. | wss/r |
| B. | r/wss |
| C. | wss/2r |
| D. | r/2wss |
| Answer» B. r/wss | |
| 40. |
Which modulation scheme is preferred for direct sequence spread spectrum process? |
| A. | bpsk |
| B. | qpsk |
| C. | bpsk & qpsk |
| D. | none of the mentioned |
| Answer» D. none of the mentioned | |
| 41. |
Processing gain is given as |
| A. | wss/r |
| B. | rch/r |
| C. | wss/r & rch/r |
| D. | none of the mentioned |
| Answer» D. none of the mentioned | |
| 42. |
Chip is defined as |
| A. | shortest uninterrupted waveform |
| B. | largest uninterrupted waveform |
| C. | shortest diversion |
| D. | none of the mentioned |
| Answer» B. largest uninterrupted waveform | |
| 43. |
DS/BPSK includes |
| A. | despreading |
| B. | demodulation |
| C. | despreading & demodulation |
| D. | none of the mentioned |
| Answer» D. none of the mentioned | |
| 44. |
In direct sequence process which step is performed first? |
| A. | de-spreading |
| B. | demodulation |
| C. | despreading & demodulation |
| D. | none of the mentioned |
| Answer» B. demodulation | |
| 45. |
The jammer which monitors a communicator’s signal is known as |
| A. | frequency follower jammers |
| B. | repeat back jammers |
| C. | frequency follower & repeat back jammers |
| D. | none of the mentioned |
| Answer» D. none of the mentioned | |
| 46. |
Which jamming method produces greater degradation? |
| A. | broadband jamming |
| B. | partial jamming |
| C. | broadband & partial jamming |
| D. | none of the mentioned |
| Answer» C. broadband & partial jamming | |
| 47. |
To increase error probability, the processing gain should be |
| A. | increased |
| B. | decreased |
| C. | exponentially increased |
| D. | exponentially decreased |
| Answer» B. decreased | |
| 48. |
The broadband jammer jams the entire |
| A. | w |
| B. | wss |
| C. | w & wss |
| D. | none of the mentioned |
| Answer» C. w & wss | |
| 49. |
The system should have |
| A. | larger (j/s)reqd |
| B. | greater system’s noise rejection capability |
| C. | larger (j/s)reqd & greater system’s noise rejection capability |
| D. | none of the mentioned |
| Answer» D. none of the mentioned | |
| 50. |
The ratio (J/S)reqd gives the measure of |
| A. | vulnerability to interference |
| B. | invulnerability to interference |
| C. | all of the mentioned |
| D. | none of the mentioned |
| Answer» C. all of the mentioned | |