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प्रश्न
Draw a schematic sketch showing how amplitude modulated signal is obtained by superposing a modulating signal over a sinusoidal carrier wave.
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उत्तर
Amplitude modulated signal is obtained by superposing a modulating signal over a sinusoidal carrier wave is shown in the figure given below
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संबंधित प्रश्न
Explain any two factors that justify the need of modulating a low-frequency signal.
Identify the mathematical expression for amplitude modulated wave ______.
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?
Why is a AM signal likely to be more noisy than a FM signal upon transmission through a channel?
On radiating (sending out) an AM modulated signal, the total radiated power is due to energy carried by ωc, ωc – ωm and ωc + ωm. Suggest ways to minimise cost of radiation without compromising on information.
Draw the plot of amplitude versus ‘ω’ for an amplitude modulated wave whose carrier wave (ωc) is carrying two modulating signals, ω1 and ω2 (ω2 > ω1).
- Is the plot symmetrical about ωc? Comment especially about plot in region ω < ωc.
- Extrapolate and predict the problems one can expect if more waves are to be modulated.
- Suggest solutions to the above problem. In the process can one understand another advantage of modulation in terms of bandwidth?
An audio signal vm = 20sin2π(1500t) amplitude modulates a carrier vc = 80 sin 2π (100,000t). The value of percent modulation is ______.
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 amplitude for an amplitude modulated wave is found to be 12V while the minimum amplitude is found to be 3V. The modulation index is 0.6x where x is ______.
