Frequency modulation, digital signal compression, assignment help

Frequency Modulation (FM) is: [select all that apply]

A. can be used to send digital signals
B. basically the same thing as Amplitude Modulation (AM)
C. only used for radio broadcasting from 88 MHz to 108 MHz
D. a technique used to send information in a radio wave
E. can be used to send analog signals

Select all that apply: digital signal compression…

A. is only useful for sound signals.
B. decreases bandwidth requirements.
C. is used in cell phone systems.
D. increases noise.
E. often takes advantage of repetition in a signal.

Most populous areas have hundreds of radio signals traveling through the air. It is possible to listen to just one because: [choose all that apply]

A. the signals mostly use different channels.
B. the radio transmitters all use a different polarization.
C. an antenna picks up only a single broadcast at a time.
D. a radio receiver can be tuned to a single channel.
E. the strongest signal is always the one that is received.

Which are true about data capacity of a channel?

A. Capacity of a channel is greater for digital signals than for analog signals.
B. Capacity (in bits/second) cannot be less than the bandwidth (in Hz).
C. Capacity (in bits/second) can be greater than the bandwidth (in Hz).
D. Decreasing noise will increase capacity

Creating and Sending data:

Estimate much data (in bytes) is required by the following activities (show your work!)

A) a tweet (max 140 characters)
B) a 10 page paper (just the characters in the text, not the formatting)
C) a 30 second recorded phone message (uncompressed)

A 1 Megabyte file needs to be transmitted, but the available capacity is only 100 kilobits/second. How long will it take to transmit the file?

A. 80 seconds
B. 1/80 second
C. 10 seconds
D. 100 seconds
E. 0.1 second

A radio wave is transmitted with a power of 100 Watts and can be received at distances of up to 20 miles. How much power would be required to be received at a distance of 40 miles?

A. 100 Watts
B. 400 Watts
C. 25 Watts
D. 200 Watts
E. 50 Watts