Introduction to Electronic Communication

1. Having an information signal change some characteristic of a carrier signal is called

• Multiplexing

• Modulation

• Duplexing

• Linear mixing

2. Which of the following is not true about AM?

• the carrier amplitude varies

• the carrier frequency remains constant

• the carrier frequency changes

• the information signal amplitude changes the carrier amplitude

3. The opposite of modulation is

• reverse modulation

• downward modulation

• unmodulation

• demodulation

What is the process of superimposing an intelligence frequency to a higher frequency?

• Modulation

• Detection

• Multiplexing

• Scrambling

When the carrier is modulated 75%, the total power increases by what percentage over that of the carrier alone?

• 50%

• 75%      

• 28%

• 100%

The ratio of the peak modulating signal voltage to the peak carrier voltage is referred to as

• modulation ratio

• percentage of modulation

• modulation index

• coefficient of modulation

For ideal AM, which of the following is true?

• m = 0

• m = 1

• m < 1

• m > 1

The outline of the peaks of a carrier has the shape of the modulating signal and is called the

• trace

• waveshape

• envelope

• carrier variation

Overmodulation occurs when

• Vm > Vc

• Vm < Vc

• Vm = Vc

• Vm = Vc = 0

Most of the power in an AM signal is the

• carrier

• upper sideband

• lower sideband

• modulating signal