The carrier amplitude after AM varies between 4 volts and 1 volt. The depth of modulation is
A sinusoidal carrier has an amplitude of 10 V and frequency 30 kHz. It is amplitude modulated by a sinusoidal voltage of amplitude 3 V and frequency 1 kHz. The spectrum of AM wave will be represented as
1 Crore+ students have signed up on EduRev. Have you? Download the App |
Assertion (A): The principle of envelope detection of an AM signal is based on multiplying the incoming signal with the locally generated synchronous carrier and pass the product through a LPF.
Reason (R): An envelope detector produces an output signal that follows the envelope of the input AM signal exactly.
Consider the following statements associated with the synchronous detection method for detection/demodulation of AM signals:
1. The circuit complexity is very less.
2. It introduces frequency and phase errors only.
3. it does not require any locally generated synchronous carrier.
4. It can be used for DSB-SC, SSB and VSB but not for DSB-FC.
Which of the statements given above is/are correct?
Assertion (A): in amplitude modulation, the higher percentage of modulation is preferred.
Reason (R): The modulation index of more than 100% can be achieved without compromising the envelope distortion.
(a) Both A and R are true and R is the correct explanation of A.
(b) Both A and R are true but R is not the correct explanation of A.
(c) A is true but R is false.
(d) A is false but R is true.
The types of distortions which can occur in the envelope detector output is/are
A 400 Watts carrier is modulated to a depth of 75 percent. Assuming the modulating signal to a sinusoidal one, the total power in the amplitude-modulated wave is
The modulation index of the low level emitter modulator is 0.7, voltage gain without modulating signal is AQ = 100, carrier frequency fc = 1 MHz. The amplitude of carrier is 10 mV. If the modulating frequency is 1 kHz, the range of voltage gain is
The antenna current of an AM transmitter is 8 A if only the carrier is sent, but it increases to 8.93 A if the carrier is modulated by a single sinusoidal wave. What is the antenna current when the percent of modulation is 80%?
The antenna current of an AM transmitter is 10 A when it is modulated to depth of 30% by an audio signal. It increases to 11 A when another signal modulates the carrier signal. The modulation index due to second signal is
25 docs|263 tests
|
25 docs|263 tests
|