Tag: elements of communication system

Questions Related to elements of communication system

During the process of transmission and reception, the signal gets deteriorated due to

physics communication system commonly used terms in electronic communication system elements of communication system electromagnetic waves and communication system

  1. noise introduced in the system

  2. distortion in the system

  3. both (A) and (B)

  4. neither (A) nor (B)

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Correct Option: C
Explanation:

Noise is the unwanted energy and distortion both occurring at various stage of a system leads to deterioration of signal, as signal to noise ratio becomes so poor that signal becomes unintelligible and useless.

Which of the following is not a part of receiver?

physics communication system commonly used terms in electronic communication system elements of communication system electromagnetic waves and communication system

  1. Receiving antenna

  2. Amplifier

  3. Modulator

  4. Demodulator

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Correct Option: C
Explanation:

A receiver receives the pre-modulated signal through receiving antenna, demodulates it using demodulator, and finally amplifies it to be sent as output to loudspeaker etc.

In television transmission, the light from the object is converted into signals called:

physics communication system commonly used terms in electronic communication system elements of communication system electromagnetic waves and communication system

  1. video frequency

  2. audio frequency

  3. very high frequency

  4. very low frequency

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Correct Option: A
Explanation:

The Range of frequency for the signals which is used for transmitting videos is called video frequency or VF frequency bandwidth .It ranges between 0 and the highest frequency used to transmit a live telivision image

The RF channel in a radio transmitter produces :

physics communication system commonly used terms in electronic communication system elements of communication system electromagnetic waves and communication system

  1. Audio signals

  2. Both audio signal and high frequency carrier waves

  3. High frequency carrier waves

  4. Low frequency carrier waves

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Correct Option: C
Explanation:

When audio signals are transmitted over thousands of kilometres through radio transmission, the audio frequencies that lie within the frequency range of 15 Hertz to 20 KiloHertz has very small signal power and thus cannot be transmitted via antenna for communication purposes. The radiation of electrical energy is only possible at frequencies above 20 KiloHertz.  Thus, the audio signals must be sent along with the high frequency signals for communication since the high frequency signals can travel long distance without dissipation in power. This can be done by superimposing electrical audio signals on a high frequency wave called the carrier wave by a process called modulation.

The range of frequency of audio signal is __________.

physics communication system commonly used terms in electronic communication system elements of communication system electromagnetic waves and communication system

  1. $20 Hz$ to $20 MHz$

  2. $0$ to $2 kHz$

  3. $20 Hz$ to $20 kHz$

  4. $20 kHz$ to $200 kHz$

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Correct Option: C
Explanation:

The generally accepted standard range of audible frequencies is $20 Hz$ to $20,000 Hz$, although the range of frequencies individuals hear is greatly influenced by environmental factor. Frequencies below $20 Hz$ are generally felt rather than heard, assuming the amplitude of the vibration is great enough. Frequencies above $20,000 Hz$ ($20 kHz$) frequencies are the first to be affected by hearing loss due to age and prolonged exposure to very loud noises.

What will be the image frequency of an FM radio receiver that is tuned to 91.6 MHz broadcast station?

physics communication system commonly used terms in electronic communication system elements of communication system electromagnetic waves and communication system

  1. 111.8 MHz

  2. 113 MHz

  3. 121.6 MHz

  4. 132 MHz

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Correct Option: B
Explanation:

Tuned frequency is $91.6MHz$ and corresponding oscillator frequency is $102.3MHz$. Then image frequency is $102.3+10.7 MHz = 113MHz$

The wave used by artificial satellites for communication is

physics communication system elements of a communication system elements of communication system electromagnetic waves and communication system

  1. Microwaves

  2. Infrared rays

  3. Radio rays

  4. X-rays

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Correct Option: A
Explanation:

Microwaves are mostly used for satellite communication, as microwaves can pass straight through the atmosphere and connect antennas on earth to satellite in earth's orbit.

The critical velocity of satellite of mass $100 kg$ moving round a planet is $20 m/s$. If another satellite of mass $200 kg$ is kept moving in the same orbit then its critical velocity will be:

physics communication system elements of a communication system elements of communication system electromagnetic waves and communication system

  1. $40 km/hr$

  2. $72 km/hr$

  3. $40 m/s$

  4. $72 m/s$

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Correct Option: B

In sky wave communication which of the frequency will be reflected back by the ionospheric layer having electron density $4 \times 10 ^ { 6 } / \mathrm { m } ^ { 3 }$

physics communication system elements of a communication system elements of communication system electromagnetic waves and communication system

  1. $19 \times 10 ^ { 3 } \mathrm { Hz }$

  2. $9 \times 10 ^ { 3 } H z$

  3. $31 \times 10 ^ { 3 } \mathrm { Hz }$

  4. $20 \times 10 ^ { 3 } \mathrm { Hz }$

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Correct Option: B

The examples of broadcast are
A) radio B) television
C) telephony D) internet

physics communication system elements of a communication system elements of communication system electromagnetic waves and communication system

  1. A & B

  2. A, B & D

  3. A,B & C

  4. B & D

Show answer
Correct Option: B
Explanation:

telephone is one to one, whereas internet can have have many ways of communication, but radio and television broadcast the messages.