Communication Systems Chapter 1

Radians per second is equal to: a. 2π × f c. the phase angle b. f ÷ 2π d. none of the above

A. 2π × f

The person who sent the first radio signal across the Atlantic ocean was: a. Marconi c. Maxwell b. Bell d. Hertz

A. Marconi

TDM stands for: a. Time-Division Multiplexing c. Time Domain Measurement b. Two-level Digital Modulation d. none of the above

A. Time-Division Multiplexing

When two noise voltages, V1 and V2, are combined, the total voltage VT is: a. VT = sqrt(V1 × V1 + V2 × V2) c. VT = sqrt(V1 × V2) b. VT = (V1 + V2)/2 d. VT = V1 + V2

A. VT=sqrt(V1 × V1 + V2 × V2)

The baseband bandwidth for a voice-grade (telephone) signal is: a. approximately 3 kHz c. at least 5 kHz b. 20 Hz to 15,000 Hz d. none of the above

A. approximately 3kHz

"Man-made" noise can come from: a. equipment that sparks c. static b. temperature d. all of the above

A. equipment that sparks

So called "1/f" noise is also called: a. random noise c. white noise b. pink noise d. partition noise

B. Pink Noise

A complete communication system must include: a. a transmitter and receiver b. a transmitter, a receiver, and a channel c. a transmitter, a receiver, and a spectrum analyzer d. a multiplexer, a demultiplexer, and a channel

B. a transmitter, a receiver, and a channel

"Pink" noise has: a. equal power per Hertz c. constant power b. equal power per octave d. none of the above

B. equal power per octave

FDM stands for: a. Fast Digital Modulation c. Frequency-Division Multiplexing b. Frequency Domain Measurement d. none of the above

C. Frequency-Division Multiplexing

The theory of radio waves was originated by: a. Marconi c. Maxwell b. Bell d. Hertz

C. Maxwell

Noise Figure is a measure of: a. how much noise is in a communications system b. how much noise is in the channel c. how much noise an amplifier adds to a signal d. signal-to-noise ratio in dB

C. how much noise an amplifier adds to a signal

The wavelength of a radio signal is: a. equal to f ÷ c b. equal to c ÷ λ c. the distance a wave travels in one period d. how far the signal can travel without distortion

C. the distance a wave travels in one period

The transmission of radio waves was first done by: a. Marconi c. Maxwell b. Bell d. Hertz

D. Hertz

The bandwidth required for a modulated carrier depends on: a. the carrier frequency c. the signal-plus-noise to noise ratio b. the signal-to-noise ratio d. the baseband frequency range

D. the baseband frequency range