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प्रश्न
The process of superimposing a low frequency signal on a high frequency wave is_______ .
विकल्प
detection
mixing
modulation
attenuation
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उत्तर
modulation
The process of superimposing a low frequency signal on a high frequency wave is known as modulation.
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संबंधित प्रश्न
State three important factors showing the need for translating a low frequency signal into a high frequency wave before transmission
Draw a sketch of a sinusoidal carrier wave along with a modulating signal and show how these are superimposed to obtain the resultant amplitude modulated wave
How are side bands produced?
The carrier wave is given by
C(t) = 2sin(8πt) volt.
The modulating signal is a square wave as shown. Find modulation index.
A carrier wave of peak voltage 12 V is used to transmit a message signal. What should be the peak voltage of the modulating signal in order to have a modulation index of 75%?
Why is Modulation index kept low?
What is the role of a bandpass filter?
A carrier wave of peak voltage 15 V is used to transmit a message signal. Find the peak voltage of the modulating signal in order to have a modulation index of 60%
State any two types of modulation
The carrier wave is represented by
The carrier wave of a signal is given by C(t) = 3 sin (8πt) volt. The modulating signal is a square wave as shown. Find its modulation index.
In the block diagram of a simple modulator for obtaining an AM signal, shown in the figure, identify the boxes A and B. Write their function.
In the given block diagram of a receiver, identify the boxes labeled as X and Y and write their functions.
Given modulation index physical significance .For an amplitude modulated wave, the maximum amplitude is found to be 10 V while the minimum amplitude is 2 V. Determine the modulation index μ ?
Broadcasting antennas are generally ______.
A male voice after modulation-transmission sounds like that of a female to the receiver. The problem is due to ______.
An audio signal of 15kHz frequency cannot be transmitted over long distances without modulation because ______.
- the size of the required antenna would be at least 5 km which is not convenient.
- the audio signal can not be transmitted through sky waves.
- the size of the required antenna would be at least 20 km, which is not convenient.
- effective power transmitted would be very low, if the size of the antenna is less than 5 km.
A 25 m long antenna is mounted on an antenna tower. The height of the antenna tower is 75 m. The wavelength (in meter) of the signal transmitted by this antenna would be ______.
A carrier wave Vc(t) = 160 sin(2π × 106t) volts is made to vary between Vmax = 200 V and Vmin = 120 V by a message signal Vm(t) = Am sin(2π × 103t) volts. The peak voltage Am of the modulating signal is ______.
A transmitting antenna has a height of 320 m and that of receiving antenna is 2000 m. The maximum distance between them for satisfactory communication in line of sight mode is 'd'. The value of 'd' is ______ km.
