Unit I - AM

In Amplitude Modulation, the instantaneous values of the carrier amplitude change in accordance with the amplitude and frequency variations of the modulating signal.

• True

• False

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

• a) Peak line

• b) Maximum amplitude ceiling

• c) Modulation index

• d) Envelope

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

• a) Decay

• b) Distortion

• c) Amplification

• d) Attenuation

What is the circuit used for producing AM called?

• a) Modulator

• b) Transmitter

• c) Receiver

• d) Duplexer

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

• Amplitude modulation

• Modulation frequency

• Modulation index

• Ratio of modulation

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

• a) 100

• b) 91

• c) 83.33

• d) 0

When does over-modulation occur?

• a) Modulating signal voltage < Carrier voltage

• b) Modulating signal voltage > Carrier voltage

• c) Modulating signal voltage = Carrier voltage

• d) Modulating signal voltage =0

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

• a) 0.5

• b) 0.662

• c) 0.425

• d) 0.14

. The type of signal transmission in which no power is wasted on the carrier is known as ________

• a) Amplitude modulation

• b) Frequency modulation

• c) Side band suppressed carrier signal

• d) Unsuppressed carrier

Demodulation is:

• a. Detection

• b. Recovering information from modulated signal

• c. Both a and b

• d. None of the above