MCQOPTIONS
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MCQOPTIONS
This section includes 18 Mcqs, each offering curated multiple-choice questions to sharpen your Digital Communications knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
As limit of k increases, the ratio of PB/PE becomes |
| A. | 1:2 |
| B. | 2:1 |
| C. | 1:3 |
| D. | 3:1 |
| Answer» B. 2:1 | |
| 2. |
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 |
| Answer» D. M/M+1 | |
| 3. |
Energy per symbol Es is given as |
| A. | Es=Eb(log2M) |
| B. | Es=Eb/(log2M) |
| C. | Es=2Eb(log2M) |
| D. | Es=Eb/2(log2M) |
| Answer» B. Es=Eb/(log2M) | |
| 4. |
For FSK signalling, WT is equal to |
| A. | 0 |
| B. | 1 |
| C. | 0.737 |
| D. | Infinity |
| Answer» C. 0.737 | |
| 5. |
For a BER of 10-5, which modulation scheme will require minimal power? |
| A. | QPSK |
| B. | 8-PSK |
| C. | 16-PSK |
| D. | 16-QAM |
| Answer» B. 8-PSK | |
| 6. |
Identify the modulation schemes for the shown signal constellation diagrams |
| A. | (a)-QPSK (b)-BPSK (c)-QAM |
| B. | (a)-QPSK (b)-OQPSK (c)-MSK |
| C. | (a)-OQPSK (b)-QAM (c)-QPSK |
| D. | (a)-OQPSK (b)-QPSK (c)-MSK |
| Answer» D. (a)-OQPSK (b)-QPSK (c)-MSK | |
| 7. |
Arrange the bandwidth efficiency of the following M - ary modulation schemes in descending order(A) 8 - ary PSK(B) 8 - ary FSK(C) 16- ary FSK(D) 16 - ary PSK(E) 4 - ary FSKChoose the correct answer from the options given below:(1) (D), (C), (A). (B), (E) (2) (D), (E), (A). (C), (B)(3) (C), (D), (B). (A), (E) (4) (D), (A), (E). (B), (C) |
| A. | 1 |
| B. | 2 |
| C. | 3 |
| D. | 4 |
| Answer» B. 2 | |
| 8. |
ENERGY_PER_SYMBOL_ES_IS_GIVEN_AS?$ |
| A. | Es=Eb(log2M) |
| B. | Es=Eb/(log2M) |
| C. | Es=2Eb(log2M) |
| D. | Es=Eb/2(log2M) |
| Answer» B. Es=Eb/(log2M) | |
| 9. |
As limit of k increases, the ratio of PB/PE becomes$ |
| A. | 1:2 |
| B. | 2:1 |
| C. | 1:3 |
| D. | 3:1 |
| Answer» B. 2:1 | |
| 10. |
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 |
| Answer» D. M/M+1 | |
| 11. |
For FSK signalling, WT is equal t? |
| A. | 0 |
| B. | 1 |
| C. | 0.737 |
| D. | Infinity |
| Answer» C. 0.737 | |
| 12. |
In orthogonal signalling with symbols containing more number of bits we need ____ power. |
| A. | More |
| B. | Less |
| C. | Double |
| D. | None of the mentioned |
| Answer» B. Less | |
| 13. |
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 |
| Answer» B. Does not, does | |
| 14. |
The error performance of MPSK ______ as M or k increases. |
| A. | Increases |
| B. | Decreases |
| C. | Stays constant |
| D. | None of the mentioned |
| Answer» C. Stays constant | |
| 15. |
In which system, bit stream is portioned into even and odd stream? |
| A. | BPSK |
| B. | MSK |
| C. | QPSK |
| D. | FSK |
| Answer» D. FSK | |
| 16. |
Which is more vulnerable to noise? |
| A. | 2-ary system |
| B. | 4-ary system |
| C. | Binary system |
| D. | None of the mentioned |
| Answer» C. Binary system | |
| 17. |
M-ary signalling produces _______ error performance with orthogonal signalling and _______ error performance with multiple phase signalling. |
| A. | Degraded, improved |
| B. | Improved, degraded |
| C. | Improved, improved |
| D. | Degraded, degraded |
| Answer» C. Improved, improved | |
| 18. |
The limit which represents the threshold Eb/N0 value below which reliable communication cannot be maintained is called as |
| A. | Probability limit |
| B. | Error limit |
| C. | Shannon limit |
| D. | Communication limit |
| Answer» D. Communication limit | |