This set of Analog Communications Multiple Choice Questions & Answers (MCQs) focuses on “Transmitter”.
1. Modulation is done in ________
c) Between transmitter and radio receiver
Explanation: Transmitter combines the signal which is to be carried with the radio frequency signal, or carrier signal. This process is called modulation.
2. In TV transmission, picture signal is ________ modulated.
Explanation: All analog television systems use vestigial sideband modulation, which is a form of amplitude modulation. In VSB one sideband is partially removed which further reduces the bandwidth of transmitted signal.
3. In TV transmission, sound signal is ________ modulated.
Explanation: Amplitude Modulation is invariably used for picture transmission while frequency modulation is generally used for transmission of sound due to its inherent advantages over amplitude modulation. It is not suitable for transmitting videos due to it’s large bandwidth.
4. Square Law modulators are?
a) used for frequency modulation
b) used for pulse width modulation
c) used for amplitude modulation
d) used for phase modulation
Explanation: Square Law modulators are generally used for generation of amplitude modulation. They have nonlinear current-voltage characteristics. They are highly nonlinear in low voltage region.
5. Ring Modulator is ________
a) used for DSB-SC generation
b) used for SSB-SC generation
c) is a summation modulator
d) consists three diodes connected in form of a ring
Explanation: Ring Modulator is used for generating DSB-SC waves. It is a product modulator having four diodes connected in the form of a ring.
6. What is the role of transmitter in communication system?
a) to transmit message
b) to convert one form of energy into other
c) to detect and amplify information signal from the carrier
d) to process the electrical signal from different aspects
Explanation: Transmitter is used process the electrical signal from different aspects. Transducer is used to convert one form of energy into another form and the role of receiver is to detect and amplify information signal from the carrier and Channel is a medium through which a message is transmitted.
7. What is the maximum transmission efficiency?
Explanation: The maximum transmission efficiency is 33.33%. Since 2/3 of power is in carrier which conveys no useful information. So we left with only 1/3 of power.
8. AVC stands for ________
a) Abrupt Voltage Control
b) Audio Voltage Control
c) Automatic Volume Control
d) Automatic Voltage Control
Explanation: AVC stands for Automatic Volume Control. It automatically adjusts the volume of an audio signal to make it better and also to compensate noise to some extent.
9. What is the role of Amplitude limiter in FM receiver?
d) Remove amplitude variation due to noise
Explanation: If there are any variations in the amplitude of received wave, it is due to noise. The limiter eliminates this by clipping the received modulated wave.
10. What is Carrier swing?
a) Frequency deviation
b) Width of sideband
c) Frequency deviation less than carrier frequency
d) Total variation in frequency
Explanation: Carrier swing is defined as the total variation in frequency from the lowest to highest point. It is equal to two times frequency deviation of FM signal.
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.