Amplitude Modulation

1. In Amplitude Modulation, the values of ___________ changes in accordance with the freq variations of the modulating signal.

• Carrier Frequency

• Carrier Amplitude

• Carrier Phase

What is the line connecting the positive and negative peaks of the carrier waveform called?

• Envelope

• Peak line

• Modulation index

What is the reference line for the modulating signal?

• Modulated peak line

• Zero line

• Carrier peak line

What happens when the amplitude of the modulating signal is greater than the amplitude of the carrier?

• Amplification

• Distortion

• Attenuation

The ratio between the modulating signal voltage and the carrier voltage is called?

• Modulation index

• Modulation frequency

• Ratio of modulation

Noise performance of a square law demodulator of AM signal is?

• Better than that of synchronous detector

• Weaker than that of synchronous detector

• Better than that of envelope detector

What is the percentage of modulation if the modulating signal is of 7.5V and carrier is of 9V?

• 100

• 91

• 83.33

Electrostatic interferences a sort of capacitive Coupling and is reduced by

• insulated screening

• copper coating

• Magnetic effect

When does over-modulation occur?

• Modulating signal voltage < Carrier voltage

• Modulating signal voltage = Carrier voltage

• Modulating signal voltage > Carrier voltage

What is the modulation index value if V_max=5.9v and V_min=1.2v?

• 0.425

• 0.662

• 0.14