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प्रश्न
Define the term modulation. Draw a block diagram of a simple modulator for obtaining AM signal ?
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उत्तर
Modulation is the process in which low frequency message signal is superimposed on high frequency carrier wave so that they can be transmitted over long distances.
The block diagram for a simple modulator for obtaining AM signal is shown below:
संबंधित प्रश्न
The process of superimposing a low frequency signal on a high frequency wave is_______ .
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
Why is Modulation index kept low?
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 speech signal of 3 kHz is used to modulate a carrier signal of frequency 1 MHz, using amplitude modulation. The frequencies of the sidebands will be ______.
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 ______.
