Tag: electromagnetic waves and communication system
Questions Related to electromagnetic waves and communication system
Generation, propagation and detection of electromagnetic waves is the basis of
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lasers
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reactors
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radio and television
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computer
The communication and broadcasting following the base on generation, propagation, and detection of electromagnetic waves.
The electromagnetic spectrum describes a different range of electromagnetic waves. These EM waves are a special type of wave that can travel without a medium.
Electromagnetic waves are named like this due to the fact that they have both an electric and a magnetic component. In a vacuum, EM waves always travel at the same speed i.e. the speed of light. So, other EM waves besides light are infrared, ultraviolet, radio waves, and microwaves. Therefore radio and television both are based on EM wave properties. Other options like lasers, reactors, and computers are not guided by EM waves.
Thus the correct option is C.
The attenuation of a signal is compensated by
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rectifier
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oscillator
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modulator
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amplifier
Attenuation means reduction of strength of signal, thus signals are to be amplified.
A transducer used at the transmitting end, serves the purpose of converting
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electrical signal to sound form
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sound signal to electrical form
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electrical signal to magnetic form
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sound signal to magnetic form
In this case transducer takes the sound signal and convert them to electrical signal.
During the process of modulation the RF wave is called
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Modulating wave
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Modulated wave
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Carrier wave
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Audio wave
Signals which need to be transferred are superimposed on high frequency wave, which is called carrier wave, as the name suggests it carries the signals.
Loudspeaker is a transducer used at
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receiving end.
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transmitting end.
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both (A) and (B).
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neither (A) nor (B).
Loudspeaker is a transducer which converts electrical signal transmitted by the transmitter to sound form at the receiving end.
A transducer used at the transmitting end, serves the purpose of converting
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electrical signal to sound form
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sound signal to electrical form
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electrical signal to magnetic form
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sound signal to magnetic form
The message from the information source may not be in electrical form, so to convert these information, i.e., in form of sound to electrical form, a transducer like a microphone is used.
Reception of information involves
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decoding of signal.
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storage of signal.
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interpretation of signal.
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all of the above.
The received signals is either AM or FM so it needs to be demodulated, ie., decoded to get back original signal. It also needs to be stored and interpreted at receiving end.
Main function of the RF amplifiers in a superheterodyne receiver is to
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amplify signal
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reject unwanted signal
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discriminate against image frequency signal and IF-signal
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all of the above
A superheterodyne receiver is a type of radio receiver that uses frequency mixing to convert a received signal to a fixed intermediate frequency (IF) which can be more conveniently processed than the original carrier frequency.
A carbon microphone is best used in a
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dynamo
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telephone
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transformer
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none of these
"Man-made" noise can come from:
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equipment that sparks
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temperature
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static
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all of the above
Man-made noise is a noise created due to wear and tear of electrical machinery used in transmission systems. They are due to the type of amplifiers (class B) type of pulses (wideband pulses), often caused by ignition circuits, lightning, and switching elements causing spark gaps