This set of Analog Communications Multiple Choice Questions & Answers (MCQs) focuses on “Demodulation of DSB-SC”.
1. Quantization error occurs in ________
a) Time Division Multiplexing
b) Frequency Division Multiplexing
c) Pulse Code Modulation
d) Pulse Width Modulation
Explanation: The difference between an input value and its quantized value is called quantization error or we can also see it as that when an analog number is not converted into an exact digital number. It takes place in pulse code modulation (PCM).
2. Waves of frequency 60MHz can penetrate the atmosphere.
Explanation: Any frequency above 30MHz can penetrate the atmosphere. So 60 MHz can penetrate the atmosphere.
3. Ground wave travels along surface of ground.
Explanation: Ground wave propagation uses the area between surface and ionosphere for transmission. So the statement is true.
4. Autocorrelation function of which noise is a constant?
a) white noise
b) shot noise
c) transit noise
d) extraterrestrial noise
Explanation: White noise or thermal noise or Johnson noise is an interior type of noise in communication system. It is a random signal having equal intensities at different frequencies which gives it a constant power and autocorrelation function.
5. TM stands for _________
a) Trans positional Modulation
b) Transpose Modulation
c) Thermal Modulation
d) Tuned Modulation
Explanation: TM stands for transpositional modulation. In transpositional modulation, the waveform is modified resulting in a signal where each quarter cycle is transposed in modulation process.
6. In which of the modulation, the waveform is modified resulting in a signal where each quarter cycle is transposed.
Explanation: In TM, the waveform is modified resulting in a signal where each quarter cycle is transposed in modulation process.
7. Which of the following is a reflector antenna?
a) Marconi reflector antenna
b) Corner reflector antenna
c) Helical antenna
d) Bow tie antenna
Explanation: It is corner reflector antenna that comes under reflector antenna. Helical antenna and bow tie antenna comes under travelling wave antenna and log antenna respectively.
8. Carbon microphone has a bidirectional feature.
Explanation: Carbon microphone does not have a bidirectional feature. It is ribbon microphone that has bidirectional feature.
9. In India, the subcarrier frequency for transmission of color difference signals in television is approximately ________
a) 10.47 MHZ
b) 5.4 MHZ
c) 7.67 MHZ
d) 1.3 MHZ
Explanation: Subcarrier is actually a sideband of a frequency carrier wave. It is modulated to send additional information. In India the subcarrier frequency for transmission of color difference signals in television is approximately 1.3MHz.
10. Flyback switched mode is used in television because it does not require a filter choke.
Explanation: Flyback switched mode is used in television because it does not require filter choke. It is also cheap as compare to others.
Sanfoundry Global Education & Learning Series – Analog Communications.
To practice all areas of Analog Communications, here is complete set of 1000+ Multiple Choice Questions and Answers.