MCQOPTIONS
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MCQOPTIONS
This section includes 27 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. |
What is the binary representation of 57? |
| A. | 0011 1101 |
| B. | 0101 1001 |
| C. | 0111 1001 |
| D. | 0011 1001 |
| Answer» E. | |
| 2. |
For vref = 10V, n = 6, and R= 5000 ohm, which of the following is true? |
| A. | The maximum value of the output current is 1.9375 mA |
| B. | The change in the output current if the LSB is changed from 0 to 1 is 0.03125 mA |
| C. | The change in the output current is the MSB is change from 0 to 1 is 0.5 mA |
| D. | None of the mentioned |
| Answer» C. The change in the output current is the MSB is change from 0 to 1 is 0.5 mA | |
| 3. |
Which is the Most Significant Bit and Least Significant Bit in this case? |
| A. | MSB: bN, LSB: bN |
| B. | MSB: bN, LSB: b1 |
| C. | MSB: b1, LSB: bN |
| D. | MSB: b1, LSB: b1 |
| Answer» C. MSB: b1, LSB: bN | |
| 4. |
What will be the value of the output current io, if the digital signal is in the form of b1b2b3…bn |
| A. | Vref/2R (b1/2+ b2/4 + b3/8….+bn/(2N)) |
| B. | 2Vref/R (b1/2+ b2/4 + b3/8….+bn/(2N)) |
| C. | Vref/R (b1/2+ b2/4 + b3/8….+bn/(2N)) |
| D. | none of the above |
| Answer» D. none of the above | |
| 5. |
An electrical signal can be represented in either Thevenin form or Norton From. However, Norton representation is preferred when |
| A. | The load resistance is very large as compared to the source resistance |
| B. | The load resistance is very low as compared to the source resistance |
| C. | There is no preferred case |
| D. | Both of the cases mentioned are the preferred case |
| Answer» C. There is no preferred case | |
| 6. |
A cosine wave voltage signal has a 10V RMS value and 60Hz frequency. Also at time, t=0, the value of the voltage signal is equal to its RMS value. Which of the following is the correct mathematical representation of the voltage signal? |
| A. | 10 cos(60t) |
| B. | 10 cos (120πt) |
| C. | 14.14 cos(60t + π/4) |
| D. | 14.14 cos(120πt + π/4) |
| Answer» E. | |
| 7. |
WHAT_WILL_BE_THE_VALUE_OF_THE_OUTPUT_CURRENT_IO,_IF_THE_DIGITAL_SIGNAL_IS_IN_THE_FORM_OF_B1B2B3‚ÄÖ√Ñ√∂‚ÀÖ√ˬ¨‚ÀÇBN?$# |
| A. | Vref/2R (b1/2+ b2/4 + b3/8….+bn/(2<sup>N</sup>)) |
| B. | 2Vref/R (b1/2+ b2/4 + b3/8….+bn/(2<sup>N</sup>)) |
| C. | Vref/R (b1/2+ b2/4 + b3/8….+bn/(2<sup>N</sup>)) |
| D. | none of the above |
| Answer» C. Vref/R (b1/2+ b2/4 + b3/8‚Äö√Ñ√∂‚àö√묨‚àÇ.+bn/(2<sup>N</sup>)) | |
| 8. |
RANDOM_THINGS_IN_A_COMMUNICATION_SYSTEM_ARE?$ |
| A. | Timing offset |
| B. | Device frequency |
| C. | Attenuation |
| D. | All of the mentioned |
| Answer» E. | |
| 9. |
A band-pass signal has a Fourier transform equal to$ |
| A. | One |
| B. | Zero |
| C. | Infinity |
| D. | Cannot be determined |
| Answer» C. Infinity | |
| 10. |
Which is the Most Significant Bit and Least Significant Bit in this case?$ |
| A. | MSB: b<sub>N</sub>, LSB: b<sub>N</sub> |
| B. | MSB: b<sub>N</sub>, LSB: b<sub>1</sub> |
| C. | MSB: b<sub>1</sub>, LSB: b<sub>N</sub> |
| D. | MSB: b<sub>1</sub>, LSB: b<sub>1</sub> |
| Answer» E. | |
| 11. |
Which_can_be_used_for_periodic_and_non_periodic?$ |
| A. | Fourier series |
| B. | Fourier transforms |
| C. | Fourier series & transforms |
| D. | None of the mentioned |
| Answer» C. Fourier series & transforms | |
| 12. |
Which are non negative functions? |
| A. | |
| B. | PMF |
| C. | PDF & PMF |
| D. | None of the mentioned |
| Answer» D. None of the mentioned | |
| 13. |
Cumulative distributive function is |
| A. | Non negative |
| B. | Non decreasing |
| C. | Non negative & decreasing |
| D. | None of the mentioned |
| Answer» D. None of the mentioned | |
| 14. |
Which are orthonormal signal representation? |
| A. | Sine and cosine at same frequency |
| B. | Wavelets |
| C. | Complex sinusoids at a different frequency |
| D. | All of the mentioned |
| Answer» E. | |
| 15. |
A_band-pass_signal_has |
| A. | DC component |
| B. | No DC component |
| C. | No side lobes |
| D. | Cannot be determined |
| Answer» C. No side lobes | |
| 16. |
Fourier transform of a signal gives th? |
| A. | Frequency content |
| B. | Bandwidth |
| C. | Frequency content & Bandwidth |
| D. | None of the mentioned |
| Answer» D. None of the mentioned | |
| 17. |
ADSL has _____ information channels. |
| A. | One |
| B. | Three |
| C. | Four |
| D. | None of the mentioned |
| Answer» C. Four | |
| 18. |
In down-conversion multiplication with cosine wave is followed by |
| A. | Low pass filter |
| B. | High pass filter |
| C. | Bandpass filter |
| D. | Bandstop filter |
| Answer» B. High pass filter | |
| 19. |
An electrical signal can be represented in either Thevenin form or Norton From. However, Thevenin representation is preferred when |
| A. | The load resistance is very large as compared to the source resistance |
| B. | The load resistance is very low compared to the source resistance |
| C. | There is no preferred case. |
| D. | Both of the cases mentioned are the preferred case |
| Answer» B. The load resistance is very low compared to the source resistance | |
| 20. |
A band-pass signal can be down-converted using |
| A. | Sine wave |
| B. | Cosine wave |
| C. | Time delayed wave |
| D. | None of the mentioned |
| Answer» C. Time delayed wave | |
| 21. |
In compact disc (CD) audio technology, the signal is sampled at 44kHz. Each sample is represented by 16bits. What is the speed of the system in bits/second? |
| A. | 1.34 bits/second |
| B. | 2,750 bits/second |
| C. | 704,000 bits/second |
| D. | 1,441,792,000 bits/second |
| Answer» D. 1,441,792,000 bits/second | |
| 22. |
A base-band signal can be up-converted using |
| A. | Sine wave |
| B. | Cosine wave |
| C. | Filtering |
| D. | None of the mentioned |
| Answer» C. Filtering | |
| 23. |
Consider an N-bits ADC (Analog to Digital Converter) whose analog input varies from 0 to Vmax, then which of the following is not true? |
| A. | The least significant bit correspond to a change of V<sub>max</sub>/2<sup>N</sup> -1 in the analog signal |
| B. | The resolution of the ADC is V<sub>max</sub>/2<sup>N</sup> -1 |
| C. | The maximum error in the conversion (or quantization error) is V<sub>max</sub>/2(2<sup>N</sup> -1) |
| D. | None of the mentioned |
| Answer» E. | |
| 24. |
Properties of Fourier transform are |
| A. | Duality property |
| B. | Time shifting property |
| C. | Modulation property |
| D. | All of the mentioned |
| Answer» E. | |
| 25. |
Which of the following is a characteristic of digital signal? |
| A. | It takes quantized value |
| B. | Its waveform is a continuous function |
| C. | The maximum number of signals that can be produced by N bits is 2<sup>N-1</sup> |
| D. | There is no loss of value after converting an analog signal to digital signal |
| Answer» B. Its waveform is a continuous function | |
| 26. |
Properties of impulse function are |
| A. | Symmetry |
| B. | Time scaling |
| C. | Shifting |
| D. | All of the mentioned |
| Answer» E. | |
| 27. |
In the digital communication system, signals in different frequency bands are |
| A. | Orthogonal |
| B. | Non orthogonal |
| C. | Orthogonal & Non orthogonal |
| D. | None of the mentioned |
| Answer» B. Non orthogonal | |