MCQOPTIONS
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MCQOPTIONS
This section includes 77 Mcqs, each offering curated multiple-choice questions to sharpen your Analog Communications knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
Square Law modulators ________ |
| A. | used for amplitude modulation |
| B. | have non linear current-voltage characteristics |
| C. | have non linear current-voltage characteristics as well as used for Amplitude Modulation |
| D. | used for frequency modulation |
| Answer» D. used for frequency modulation | |
| 2. |
Amplitude Modulated wave is ________ |
| A. | Sum of carrier and modulating wave |
| B. | Product of carrier and modulating wave |
| C. | Difference of carrier and modulating wave |
| D. | Sum of carrier and its product with modulating wave |
| Answer» B. Product of carrier and modulating wave | |
| 3. |
Find the total power of amplitude modulated wave? |
| A. | 453W |
| B. | 675W |
| C. | 789W |
| D. | 451W |
| Answer» E. | |
| 4. |
Carrier power of the wave is? |
| A. | 555W |
| B. | 675W |
| C. | 450W |
| D. | 310W |
| Answer» D. 310W | |
| 5. |
What is its sideband power? |
| A. | 4W |
| B. | 1W |
| C. | 3W |
| D. | 2W |
| Answer» C. 3W | |
| 6. |
Commercial frequency deviation is ________ |
| A. | 75 KHz |
| B. | 80 KHz |
| C. | 85 KHz |
| D. | 65 KHz |
| Answer» B. 80 KHz | |
| 7. |
Modem is considered as high speed if data rate is ________ |
| A. | 10000 |
| B. | 20000 |
| C. | 5000 |
| D. | 30000 |
| Answer» D. 30000 | |
| 8. |
Scanning always takes place from ________ |
| A. | right to left |
| B. | left to right |
| C. | left to right for odd fields and right to left for even fields |
| D. | left to right for even fields and right to left for odd fields |
| Answer» C. left to right for odd fields and right to left for even fields | |
| 9. |
What do you understand by the term 'carrier'? |
| A. | waveform with constant frequency, phase and amplitude |
| B. | waveform for which frequency, amplitude or phase is varied |
| C. | waveform with high amplitude, low frequency and constant phase |
| D. | waveform to be transmitted |
| Answer» C. waveform with high amplitude, low frequency and constant phase | |
| 10. |
Inductance and capacitance of a line is 0.8 µH⁄m and 32 pF⁄m. Find Z0 )? |
| A. | 158 |
| B. | 166 |
| C. | 143 |
| D. | 127 |
| Answer» B. 166 | |
| 11. |
If the modulating frequency of a carrier wave varies between 700Hz and 7KHz, find it's bandwidth? |
| A. | 10 KHz |
| B. | 23 KHz |
| C. | 17.3 KHz |
| D. | 12.6 KHz |
| Answer» E. | |
| 12. |
FSK system involves ________ |
| A. | frequency modulation |
| B. | pulse modulation |
| C. | amplitude modulation |
| D. | phase modulation |
| Answer» B. pulse modulation | |
| 13. |
Diameter of antenna is doubled. The maximum range will ________ |
| A. | be doubled |
| B. | be halved |
| C. | become four times |
| D. | decrease to one fourth |
| Answer» B. be halved | |
| 14. |
If modulation index of an AM wave is increased from 1.5 to 2, then the transitted power ________ |
| A. | remains same |
| B. | increases by 20% |
| C. | increases by 41% |
| D. | increases by 50% |
| Answer» D. increases by 50% | |
| 15. |
The voltage and electric current of a line are respectively 5kV and 1000µA. Find its power? |
| A. | 12W |
| B. | 13W |
| C. | 5W |
| D. | 10W |
| Answer» D. 10W | |
| 16. |
To get constant time delay, we should use ________ |
| A. | FDM technique |
| B. | WDM technique |
| C. | Synchronous TDM |
| D. | Non synchronous TDM |
| Answer» D. Non synchronous TDM | |
| 17. |
Time Division Multiplexing (TDM) is based on orthogonality. |
| A. | True |
| B. | False |
| Answer» B. False | |
| 18. |
Which modulation technique uses minimum bandwidth? |
| A. | DSB-SC |
| B. | SSB-SC |
| C. | FM |
| D. | VSB |
| Answer» C. FM | |
| 19. |
AM waves is represented by Et cos ??c t. What does Et denotes? |
| A. | envelope |
| B. | carrier signal |
| C. | modulating signal |
| D. | amplitude |
| Answer» B. carrier signal | |
| 20. |
Wireless communication takes place through ________ |
| A. | EM waves |
| B. | X-Rays |
| C. | Optical Fibres |
| D. | Infrared Waves |
| Answer» B. X-Rays | |
| 21. |
Noise gets mixed with signal at ________ |
| A. | receiver |
| B. | transmitter |
| C. | transducer |
| D. | channel |
| Answer» E. | |
| 22. |
In a receiver, distortion can occur in ________ |
| A. | Mixer |
| B. | Detector |
| C. | IF amplifiers |
| D. | Either mixer or detector or IF amplifiers |
| Answer» E. | |
| 23. |
TV remote control used ultra violet light. |
| A. | True |
| B. | False |
| Answer» C. | |
| 24. |
What we use for impedance matching in RF amplifiers? |
| A. | RC coupling |
| B. | Transformer coupling |
| C. | Direct coupling |
| D. | RF coupling |
| Answer» C. Direct coupling | |
| 25. |
How capacitance is related with thickness? |
| A. | it is inversely proportional to thickness |
| B. | it is directly proportional to thickness |
| C. | it is inversely proportional to twice of thickness |
| D. | it is directly proportional to twice of thickness |
| Answer» B. it is directly proportional to thickness | |
| 26. |
If the transmitted power is 100KW then the field at a distance 'R' is 60mV/m. Suppose if the transmitted power is reduced to 50KW then the field at same distance 'R' will be equal to ________ |
| A. | 50mV/m |
| B. | 42mV/m |
| C. | 45mV/m |
| D. | 55mV/m |
| Answer» C. 45mV/m | |
| 27. |
EM waves are attenuated as they travel. |
| A. | True |
| B. | False |
| Answer» B. False | |
| 28. |
The gain of antenna (G) is the ratio of power radiated in a particular direction to the power radiated from an isotropic antenna. |
| A. | True |
| B. | False |
| Answer» B. False | |
| 29. |
If the power density at a given distance 'R' is one microwatt per square meter and the effective area of antenna is one square meter then the power captured by antenna is one microwatt. |
| A. | True |
| B. | False |
| Answer» B. False | |
| 30. |
If a FM signal having modulation index m_f is passed through a frequency tripler, then the modulation index of output of frequency tripler is ________ |
| A. | mf |
| B. | 3mf |
| C. | 1⁄3 mf |
| D. | 1⁄9 mf |
| Answer» C. 1⁄3 mf | |
| 31. |
What is the capacitive reactance for DC signals? |
| A. | zero |
| B. | very low |
| C. | equal to one |
| D. | infinite |
| Answer» E. | |
| 32. |
If the spectrum of a narrow band noise is symmetrical and it has a power density spectrum 4×10-6. Power density of quadrature component is ________ |
| A. | 2 x 10-6 |
| B. | 5 x 10-6 |
| C. | 3 x 10-6 |
| D. | 4 x 10-6 |
| Answer» B. 5 x 10-6 | |
| 33. |
What are the two major drawbacks of delta modulation? |
| A. | Slope Overload and Granular noise |
| B. | Slope Overload and Serration noise |
| C. | Serration noise and Granular noise |
| D. | Slope Overload and Channel Noise |
| Answer» B. Slope Overload and Serration noise | |
| 34. |
Approximate how many times odd and even fields of television system are scanned? |
| A. | 25 times each |
| B. | 50 times each |
| C. | 50 times each but alternately |
| D. | 25 times each but alternately |
| Answer» E. | |
| 35. |
Consider a wave, v = 15 sin (3pt + 5sin1300t), what is the carrier and signal frequency? |
| A. | 2.5Hz and 200Hz |
| B. | 1.5Hz and 100Hz |
| C. | 1.5Hz and 207Hz |
| D. | 5.5Hz and 500Hz |
| Answer» D. 5.5Hz and 500Hz | |
| 36. |
Beam width of antenna is expressed in ________ |
| A. | metres |
| B. | degrees |
| C. | radian |
| D. | volt |
| Answer» C. radian | |
| 37. |
A system has a voltage of 15V and it produces a total current of 1300µA. Find the power of system? |
| A. | 0.025W |
| B. | 0.035W |
| C. | 0.0195W |
| D. | 0.045W |
| Answer» D. 0.045W | |
| 38. |
The approximate aspect ratio for television is ________ |
| A. | 2 : 1 |
| B. | 3 : 2 |
| C. | 4 : 3 |
| D. | 3 : 4 |
| Answer» D. 3 : 4 | |
| 39. |
Find the step size of a signal with peak to peak amplitude of 4V and is quantized into 64 levels? |
| A. | 32.3 x 10-3 |
| B. | 30.23 x 10-3 |
| C. | 62.5 x 10-3 |
| D. | 53.3 x 10-3 |
| Answer» D. 53.3 x 10-3 | |
| 40. |
If the step size of a system is 0.0625, find its quantization power? |
| A. | 3.25 x 10-3 |
| B. | 3.25 x 10-4 |
| C. | 3.25 x 10-2 |
| D. | 3.25 x 10-1 |
| Answer» C. 3.25 x 10-2 | |
| 41. |
Signal to Noise ratio for a hi-fi system is equal to ________ |
| A. | 50 dB |
| B. | 100 dB |
| C. | 75 dB |
| D. | 10 dB |
| Answer» B. 100 dB | |
| 42. |
If a wave is modulated by two waves. One of them has modulation index equal to 0.75 and other has 0.2, the total modulation index will be ________ |
| A. | 0.67 |
| B. | 0.58 |
| C. | 0.77 |
| D. | 0.35 |
| Answer» D. 0.35 | |
| 43. |
Find the power saving for DSB-SC wave with 100% modulation? |
| A. | 0.66 |
| B. | 0.86 |
| C. | 0.5 |
| D. | 0.33 |
| Answer» B. 0.86 | |
| 44. |
Power of carrier wave is 300W and modulation index is 0.75. Find its total power? |
| A. | 465W |
| B. | 384W |
| C. | 323W |
| D. | 502W |
| Answer» C. 323W | |
| 45. |
On which factor the bandwidth required for a modulated carrier depends? |
| A. | baseband frequency range |
| B. | signal to noise ratio |
| C. | carrier frequency |
| D. | amplitude of carrier frequency |
| Answer» B. signal to noise ratio | |
| 46. |
When two or more signals share a common channel, it is called ________ |
| A. | sub-channeling |
| B. | channeling |
| C. | switching |
| D. | multiplexing |
| Answer» E. | |
| 47. |
Mixing is used in communication to ________ |
| A. | raise the carrier frequency |
| B. | lower the carrier frequency |
| C. | to altered the deviation |
| D. | to change the carrier frequency to any required value |
| Answer» E. | |
| 48. |
Sensitivity measures ________ |
| A. | weakest signal that is received at the receiver |
| B. | strongest signal that is received at the receiver |
| C. | weakest frequency signal that is received at the receiver |
| D. | strongest frequency signal that is received at the receiver |
| Answer» B. strongest signal that is received at the receiver | |
| 49. |
What is the full form of LATA? |
| A. | Local Access Telephone Area |
| B. | Local Area Telephone Access |
| C. | Local Access and Transport Area |
| D. | Local Area Transport Access |
| Answer» D. Local Area Transport Access | |
| 50. |
Selectivity measures ________ |
| A. | the range of frequencies that receiver can select |
| B. | with two signals close in frequency, the ability to select one and reject other |
| C. | how well adjacent frequencies are separated by the demodulator |
| D. | how well adjacent frequencies are separated in the mixer |
| Answer» B. with two signals close in frequency, the ability to select one and reject other | |