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प्रश्न
The frequencies of two side bands in an AM wave are 640 kHz and 660 kHz respectively. Find the frequencies of carrier and modulating signal. What is the bandwidth required for amplitude modulation?
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उत्तर
Let frequency of carrier wave be fc and frequency of modulating wave be fm
fc+ fm = 660 kHz ....... (i)
fc− fm = 640 kHz ....... (ii)
Solving (i) and (ii), we get
2 fc = 1300
⇒ fc = 650 kHz
Now,
fc+ fm = 660 kHz
650+ fm = 660 kHz
⇒fm = 10 kHz
We know,
Bandwidth = 2×fm = 20 kHz
Hence,
Frequency of carrier signal is 650 kHz
Frequency of modulating signal is 10 kHz
Bandwidth required for amplitude modualtion is 20 kHz
संबंधित प्रश्न
A signal of 5 kHz frequency is amplitude modulated on a carrier wave of frequency 2 MHz. What are the frequencies of the side bands produced?
Explain the process of amplitude modulation.
How is amplitude modulation achieved?
What is meant by term ‘modulation’? Draw a block diagram of a simple modulator for obtaining an AM signal.
Define amplitude modulation in a communication system.
In amplitude modulation ______.
In amplitude modulation, the modulation index m, is kept less than or equal to 1 because ______.
- m > 1, will result in interference between carrier frequency and message frequency, resulting into distortion.
- m > 1 will result in overlapping of both side bands resulting into loss of information.
- m > 1 will result in change in phase between carrier signal and message signal.
- m > 1 indicates amplitude of message signal greater than amplitude of carrier signal resulting into distortion.
The maximum amplitude of an A.M. wave is found to be 15 V while its minimum amplitude is found to be 3 V. What is the modulation index?
An amplitude modulated wave is as shown in figure. Calculate
- the percentage modulation
- peak carrier voltage and
- peak value of information voltage.
A signal of 5 kHz frequency is amplitude modulated on a carrier wave of frequency 2 MHz. The frequencies of the resultant signal are ______.
