Q. Given below is a circuit diagram of an demodulator. For good demodulation of signal of carrier frequency the value of should be Physics Question Image

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Solution:

From the modulated signal, we can demodulate or detect the modulating or message signal by using a diode and a suitable capacitor filter. The signal given to the input of the circuit appears at the output of the diode as a rectified wave. For good demodulation of signal the value of (which is a time-constant) is chosen such that
or
where is the frequency of the carrier signal.