MCQOPTIONS
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MCQOPTIONS
This section includes 22 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. |
In a TDD one channel is sufficient for transmission. |
| A. | True |
| B. | False |
| Answer» B. False | |
| 2. |
Which of the following type of multiplexing uses pulse code modulation? |
| A. | Frequency division multiplexing |
| B. | Time division multiplexing |
| C. | Code division multiplexing |
| D. | Amplitude limited multiplexing |
| Answer» C. Code division multiplexing | |
| 3. |
Sample resolution for LPCM ____ bits per sample. |
| A. | 8 |
| B. | 16 |
| C. | 24 |
| D. | All of the mentioned |
| Answer» E. | |
| 4. |
Delta modulation uses _____ bits per sample. |
| A. | One |
| B. | Two |
| C. | Four |
| D. | Eight |
| Answer» B. Two | |
| 5. |
DELTA_MODULATION_USES_______BITS_PER_SAMPLE.?$ |
| A. | One |
| B. | Two |
| C. | Four |
| D. | Eight |
| Answer» B. Two | |
| 6. |
Adaptive DPCM is used to$ |
| A. | Increase bandwidth |
| B. | Decrease bandwidth |
| C. | Increase SNR |
| D. | None of the mentioned |
| Answer» C. Increase SNR | |
| 7. |
Sample resolution for LPCM ____ bits per sample.$ |
| A. | 8 |
| B. | 16 |
| C. | 24 |
| D. | All of the mentioned |
| Answer» E. | |
| 8. |
In a TDD one channel is sufficient for transmission? |
| A. | True |
| B. | False |
| Answer» B. False | |
| 9. |
DPCM encodes the PCM values based o? |
| 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 | |
| 10. |
All local and long-distance connections are digital. |
| A. | True |
| B. | False |
| Answer» B. False | |
| 11. |
In PCM the samples are dependent on ________ |
| A. | Time |
| B. | Frequency |
| C. | Quanization leavel |
| D. | Interval between quantization level |
| Answer» B. Frequency | |
| 12. |
A special PCM system uses 16 channels of data, one whose purpose is an identification (ID) and synchronization. The sampling rate is 3.5 kHz. The word length is 6 bits. Find the serial data rate. |
| A. | 451kHz |
| B. | 326kHz |
| C. | 152kHz |
| D. | 336kHz |
| Answer» E. | |
| 13. |
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 | |
| 14. |
A special PCM system uses 16 channels of data, one whose purpose is an identification (ID) and synchronization. The word length is 6 bits. Find the number of bits per frame. |
| A. | 94 |
| B. | 95 |
| C. | 96 |
| D. | 125 |
| Answer» D. 125 | |
| 15. |
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 | |
| 16. |
A special PCM system uses 16 channels of data, one whose purpose is identification (ID) and synchronization. Find (a) the number of available data channels. |
| A. | 15 |
| B. | 16 |
| C. | 14 |
| D. | 18 |
| Answer» B. 16 | |
| 17. |
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 | |
| 18. |
Which of the following is false with respect to PCM? |
| A. | Reliable |
| B. | Inexpensive |
| C. | Resistant to noise |
| D. | Not easily recoverable |
| Answer» E. | |
| 19. |
Quantization noise can be reduced by ________ the number of levels. |
| A. | Decreasing |
| B. | Increasing |
| C. | Doubling |
| D. | Squaring |
| Answer» C. Doubling | |
| 20. |
Which of the following statements is true with respect to PCM? |
| A. | The parallel binary data is converted into serial before transmission |
| B. | Analog data is transmitted directly |
| C. | Analog signal is amplified before transmission |
| D. | The analog signal is converted into parallel binary data before transmission |
| Answer» B. Analog data is transmitted directly | |
| 21. |
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 | |
| 22. |
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 | |