WCM Chapter 4

ASK is generated is generated from the Modulating Signal with a Carrier Signal through

• Addition

• Division

• Multiplication

• Subtraction

The envelope of a AM signal varies between a maximum value of 6V and a minimum value of 2V. Determine its Modulation Index (m).

• 0.33

• 0.5

• 2

• 3

Which of the following describes FM?

• Both Amplitude and Frequency are varying.

• Both Amplitude and Frequency are held constant

• Carrier Amplitude is Constant while Carrier Frequency varies.

• Carrier Frequency is held constant while Carrier Amplitude varies.

A 10 kHz audio tone modulates a 1000 kHz Carrier. Determine the lower side frequency of the AM waveform.

• 900 kHz

• 990 kHz

• 1010 kHz

• 1100 kHz

A signal varies from 16 Hz to 10 kHz in a PCM System. Which of the following is the minimum sampling rate to avoid distortion?

• 16 Hz

• 32 Hz

• 10 kHz

• 20 kHz

Which is True for characteristic of AM waveform?

• The information signal is placed on carrier by varying the carrier frequency while holding its amplitude fixed

• The information signal is placed on carrier by fixing the carrier frequency while holding its amplitude fixed

• The amplitude of the carrier is made to vary in accordance eith the instantaneous value of the modulating signal

• Carrier has constant amplitude , but varies in frequency

The size of an Antenna is determined by its operating _____________.

• voltage

• current

• frequency

• material

The maximum amount of modulation without signal distortion occurs when modulation index , m =

• m=0

• m=0.5

• m=1

• m=2

'ASK' may be generated by __________________ the digital modulating signal with a carrier

• sum

• minus

• divide

• multiplying

Narrowband signals are used in a _______________form of communication

• faster

• slower

• fixed

• random