MCQOPTIONS
Saved Bookmarks
MCQOPTIONS
This section includes 34 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. |
In NBFM, the modulation index is close to __________ |
| A. | 1 |
| B. | greater than 1 |
| C. | 10 |
| D. | infinite |
| Answer» B. greater than 1 | |
| 2. |
NBFM stands for Narrow Band Frequency Modulation. |
| A. | True |
| B. | False |
| Answer» B. False | |
| 3. |
Which device is has more chance to be found in SSB transmitter? |
| A. | balanced modulator |
| B. | class A RF amplifier |
| C. | class C audio amplifier |
| D. | class B RF amplifier |
| Answer» B. class A RF amplifier | |
| 4. |
For a low level AM system, amplifier modulated stage must have _________ |
| A. | harmonic devices |
| B. | linear devices |
| C. | non-linear devices |
| D. | class A amplifiers |
| Answer» C. non-linear devices | |
| 5. |
If the target is changing continuously, then the best scanning system for correct tracking is _________ |
| A. | monopulse |
| B. | conical |
| C. | lobe switching |
| D. | sequential |
| Answer» B. conical | |
| 6. |
Carrier wave in modulation is a resultant wave. |
| A. | True |
| B. | False |
| Answer» C. | |
| 7. |
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 | |
| 8. |
Granular noise occurs in Delta Modulation, when ____________ |
| A. | pulse rate decreases |
| B. | pulse amplitude decreases |
| C. | modulating signal increases |
| D. | modulating signal remains constant |
| Answer» E. | |
| 9. |
For getting zero radiation at right angles, length of antenna should be __________ |
| A. | ? |
| B. | ?⁄8 |
| C. | ?⁄4 |
| D. | ?⁄5 |
| Answer» B. ?⁄8 | |
| 10. |
What is the commercial frequency deviation of frequency modulation? |
| A. | 70 KHz |
| B. | 75 KHz |
| C. | 80 KHz |
| D. | 85 KHz |
| Answer» C. 80 KHz | |
| 11. |
What is the full form of PAM? |
| A. | Pulse Analog Modulation |
| B. | Phase Analog Modulation |
| C. | Pulse Amplitude Modulation |
| D. | Phase Amplitude Modulation |
| Answer» D. Phase Amplitude Modulation | |
| 12. |
Convex lens has negative focal power and concave lens have positive focal power. |
| A. | True |
| B. | False |
| Answer» C. | |
| 13. |
All lens have positive focal power. |
| A. | True |
| B. | False |
| Answer» C. | |
| 14. |
DVD uses laser beam for recording and video head for playback. |
| A. | True |
| B. | False |
| Answer» C. | |
| 15. |
For telegraphy pulse code modulation (PCM) is widely used. |
| A. | True |
| B. | False |
| Answer» C. | |
| 16. |
Leak type bias is used in plate modulated amplifier to prevent tuned circuit damping. |
| A. | True |
| B. | False |
| Answer» C. | |
| 17. |
Base modulation is preferred over collector modulation of a class C transistor because it has high power output per transistor. |
| A. | True |
| B. | False |
| Answer» C. | |
| 18. |
Balanced modulator is used to produce balanced modulation of a carrier wave. |
| A. | True |
| B. | False |
| Answer» C. | |
| 19. |
Frequency modulated broadcast band generally lies in ________ |
| A. | VHF |
| B. | HF |
| C. | SHF |
| D. | LF |
| Answer» B. HF | |
| 20. |
What is the standard IF frequency for AM receivers? |
| A. | 100 KHz |
| B. | 455 KHz |
| C. | 1.07 MHz |
| D. | 10.7 MHz |
| Answer» C. 1.07 MHz | |
| 21. |
Which of the following modulation is used for radio navigation? |
| A. | Pulse Modulation |
| B. | Amplitude Modulation |
| C. | Phase Modulation |
| D. | Frequency Modulation |
| Answer» B. Amplitude Modulation | |
| 22. |
Inherently most noise resistant modulating system is _________ |
| A. | PCM |
| B. | DSB |
| C. | SSB |
| D. | VSB |
| Answer» B. DSB | |
| 23. |
A cordless telephone that uses separate frequencies for transmission is known as half duplex. |
| A. | True |
| B. | False |
| Answer» C. | |
| 24. |
What is the main disadvantage of FM over AM? |
| A. | high modulating power is needed |
| B. | noise is very high for high frequencies |
| C. | high output power is required |
| D. | large bandwidth is required |
| Answer» E. | |
| 25. |
VSB modulation is used in televisions because it results in better reception. |
| A. | True |
| B. | False |
| Answer» C. | |
| 26. |
Impulse noise can be reduced in _________ |
| A. | FM |
| B. | AM |
| C. | QAM |
| D. | PM |
| Answer» B. AM | |
| 27. |
In televisions, equalizing pulses are sent during __________ |
| A. | horizontal blanking |
| B. | vertical blanking |
| C. | serrations |
| D. | horizontal retrace |
| Answer» B. vertical blanking | |
| 28. |
Vestigial side band (VSB) is most commonly used in ________ |
| A. | Television Transmission |
| B. | Radios |
| C. | Telephony |
| D. | Laser Transmission |
| Answer» B. Radios | |
| 29. |
FM signals can be generated by using ________ |
| A. | Varacter diode |
| B. | Laser diode |
| C. | Backward diode |
| D. | Gunn diode |
| Answer» B. Laser diode | |
| 30. |
What is the radio frequency range of a frequency modulated signal? |
| A. | 20-80 MHz |
| B. | 100-200 MHz |
| C. | 200-350 MHz |
| D. | 99-108 MHz |
| Answer» E. | |
| 31. |
DM stands for ________ |
| A. | Density Modulation |
| B. | Delta Modulation |
| C. | Double Side Band Modulation |
| D. | Direct Modulation |
| Answer» C. Double Side Band Modulation | |
| 32. |
What is the expected modulation index in case of wide band FM? |
| A. | less than 1 |
| B. | 1 |
| C. | 1⁄2 |
| D. | more than 1 |
| Answer» E. | |
| 33. |
Companding is used in PCM transmitters to overcome quantizing noise in PCM. |
| A. | True |
| B. | False |
| Answer» C. | |
| 34. |
In PCM system, output S/N increases ________ |
| A. | parabolically with bandwidth |
| B. | exponentially with bandwidth |
| C. | inversely with bandwidth |
| D. | linearly with bandwidth |
| Answer» C. inversely with bandwidth | |