मराठी
कर्नाटक बोर्ड पी.यू.सी.पीयूसी विज्ञान 2nd PUC Class 12

Compute the LC product of a tuned amplifier circuit required to generate a carrier wave of 1 MHz for amplitude modulation.

Advertisements
Advertisements

प्रश्न

Compute the LC product of a tuned amplifier circuit required to generate a carrier wave of 1 MHz for amplitude modulation.

टीपा लिहा
Advertisements

उत्तर

Frequency of tuned amplifier is `v = 1/(2pisqrt(LC))`

As per question, `v = 1 MHz = 10^6 Hz`

or `10^6 = 1/(2pisqrt(LC))`

or LC = `1/(4pi^2 (10^6)^2` = 2.5 × 10–14s

shaalaa.com
  या प्रश्नात किंवा उत्तरात काही त्रुटी आहे का?
पाठ 15: Communication Systems - Exercise [पृष्ठ १०२]

APPEARS IN

एनसीईआरटी एक्झांप्लर Physics Exemplar [English] Class 12
पाठ 15 Communication Systems
Exercise | Q 15.19 | पृष्ठ १०२

व्हिडिओ ट्यूटोरियलVIEW ALL [1]

संबंधित प्रश्‍न

Draw a block diagram of a detector for AM signal and show, using necessary processes and the waveforms, how the original message signal is detected from the input AM wave.


For an amplitude modulated wave, the maximum amplitude is found to be 10 V while the minimum amplitude is found to be 2 V. Determine the modulation index μ. What would be the value of μ if the minimum amplitude is zero volt?


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?


Draw a schematic sketch showing how amplitude modulated signal is obtained by superposing a modulating signal over a sinusoidal carrier wave.


Write two advantages of frequency modulation over amplitude modulation.


Write three important factors which justify the need of modulating a message signal. Show diagrammatically how an amplitude modulated wave is obtained when a modulating signal is superimposed on a carrier wave.


Answer the following question.
If A and B represent the maximum and minimum amplitudes of an amplitude-modulated wave, write the expression for the modulation index in terms of A and B.


Define amplitude modulation in a communication system.


In amplitude modulation ______.


A message signal of frequency ωm is superposed on a carrier wave of frequency ωc to get an amplitude modulated wave (AM). The frequency of the AM wave will be ______.


Identify the mathematical expression for amplitude modulated wave ______.


In amplitude modulation, the modulation index m, is kept less than or equal to 1 because ______.

  1. m > 1, will result in interference between carrier frequency and message frequency, resulting into distortion.
  2. m > 1 will result in overlapping of both side bands resulting into loss of information.
  3. m > 1 will result in change in phase between carrier signal and message signal.
  4. 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?


Why is a AM signal likely to be more noisy than a FM signal upon transmission through a channel?


Draw the plot of amplitude versus ‘ω’ for an amplitude modulated wave whose carrier wave (ωc) is carrying two modulating signals, ω1 and ω22 > ω1). 

  1. Is the plot symmetrical about ωc? Comment especially about plot in region ω < ωc.
  2. Extrapolate and predict the problems one can expect if more waves are to be modulated.
  3. Suggest solutions to the above problem. In the process can one understand another advantage of modulation in terms of bandwidth?

An amplitude-modulated wave is represented by Cm(t) = 10(1 + 0.2 cos 12560t) × sin (111 × 104t) volts. The modulating frequency in kHz will be ______.


The maximum and minimum voltage of an amplitude modulated signal are 60 V and 20 V respectively. The percentage modulation index will be ______.


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×