Forouzan Chapter 3 MCQ

Question 1

1. If the maximum amplitude of a sine wave is 2 V, the minimum amplitude is ________ V.
   A) 2

B) 1

C) -2

D) between -2 and 2

Answer 1

C

Question 2

_________ can impair a signal.

A) Noise

B) Attenuation

C) Distortion

D) All of the above

Answer 2

D

Question 3

________is the rate of change with respect to time.

A) Time

B) Frequency

C) Amplitude

D) Voltage

Answer 3

B

Question 4

A signal is measured at two different points. The power is P1 at the first point and P2 at the second point. The dB is 0. This means ________.

A) P2 equals P1

B) P2 is zero

C) P2 is much larger than P1

D) P2 is much smaller than P1

Answer 4

A

Question 5

Baseband transmission of a digital signal is possible only if we have a ____ channel.

A) bandpass

B) low-pass

C) high rate

D) low rate

Answer 5

B

Question 6

________ is a type of transmission impairment in which the signal loses strength due to the resistance of the transmission medium.

A) Distortion

B) Attenuation

C) Noise

D) Decibel

Answer 6

B

Question 7

A sine wave in the ______ domain can be represented by one single spike in the _____ domain.

A) time; phase

B) frequency; time

C) time; frequency

D) phase; time

Answer 7

C

Question 8

If the bandwidth of a signal is 5 KHz and the lowest frequency is 52 KHz, what is the highest frequency?

A) 5 KHz

B) 47 KHz

C) 57 KHz

D) 10 KHz

Answer 8

C

Question 9

In a time-domain plot, the horizontal axis is a measure of ________.

A) phase

B) signal amplitude

C) frequency

D) time

Answer 9

D

Question 10

_______ data are continuous and take continuous values.

A) digital

B) analog

C) (a) or (b)

D) none of the above

Answer 10

B

Question 11

Frequency and period are ______.

A) proportional to each other

B) inverse of each other

C) the same

D) none of the above

Answer 11

B

Question 12

When propagation speed is multiplied by propagation time, we get the ________.

A) wavelength of the signal

B) throughput

C) distance a signal or bit has traveled

D) distortion factor

Answer 12

C

Question 13

A _________ sine wave is not useful in data communications; we need to send a _______ signal.

A) single-frequency; composite

B) composite; single-frequency This is the correct answer.

C) single-frequency; double-frequency

D) none of the above

Answer 13

A

Question 14

The _________ product defines the number of bits that can fill the link.

A) delay-amplitude

B) frequency-amplitude

C) bandwidth-period

D) bandwidth-delay

Answer 14

D

Question 15

_______ signals can have only a limited number of values.

A) Digital

B) Analog

C) (a) or (b)

D) None of the above

Answer 15

A

Question 16

Before data can be transmitted, they must be transformed to ________.

A) periodic signals

B) electromagnetic signals

C) aperiodic signals

D) low-frequency sine waves

Answer 16

B

Question 17

Data can be ________.

A) digital

B) analog

C) (a) or (b)

D) none of the above

Answer 17

C

Question 18

________ is a type of transmission impairment in which the signal loses strength due to the different propagation speeds of each frequency that makes up the signal.

A) Noise

B) Distortion

C) Attenuation

D) Decibel

Answer 18

B

Question 19

Signals can be ________.

A) digital

B) analog

C) either (a) or (b)

D) neither (a) nor (b)

Answer 19

C

Question 20

A sine wave is ________.

A) periodic and discrete

B) aperiodic and discrete

C) periodic and continuous

D) aperiodic and continuous

Answer 20

C

Question 21

_______ data have discrete states and take discrete values.

A) Analog

B) Digital

C) (a) or (b)

D) None of the above

Answer 21

B

Question 22

For a ______ channel, we need to use the Shannon capacity to find the maximum bit rate.

A) noiseless

B) noisy

C) low-pass

D) bandpass

Answer 22

B

Question 23

What is the bandwidth of a signal that ranges from 1 MHz to 4 MHz?

A) 1 KHz

B) 3 MHz

C) 4 MHz

D) none of the above

Answer 23

B

Question 24

_____ signals can have an infinite number of values in a range.

A) Analog

B) Digital

C) (a) or (b)

D) None of the above

Answer 24

A

Question 25

A(n)_________ signal is a composite analog signal with an infinite bandwidth. A) digital B) analog C) either (a) or (b) D) neither (a) nor (b)

Answer 25

A

Question 26

A periodic signal completes one cycle in 0.001 s. What is the frequency? A) 1 Hz B) 100 Hz C) 1 KHz D) 1 MHz

Answer 26

C

Question 27

The _____ of a composite signal is the difference between the highest and the lowest frequencies contained in that signal. A) period B) bandwidth C) frequency D) amplitude

Answer 27

B

Question 28

. ________ is a type of transmission impairment in which an outside source such as crosstalk corrupts a signal. A) Noise B) Distortion C) Attenuation D) Decibel

Answer 28

A

Question 29

_______ describes the position of the waveform relative to time 0. A) Amplitude B) Phase C) Frequency D) Voltage

Answer 29

B

Question 30

Given two sine waves A and B, if the frequency of A is twice that of B, then the period of B is ________ that of A. A) one-half B) twice C) the same as D) indeterminate from

Answer 30

B

Question 31

As frequency increases, the period ________. A) increases B) decreases C) doubles D) remains the same

Answer 31

B

Question 32

If the available channel is a ______ channel, we cannot send a digital signal directly to the channel. A) low-pass B) low rate C) bandpass D) high rate

Answer 32

C

Question 33

For a ______ channel, the Nyquist bit rate formula defines the theoretical maximum bit rate. A) low-pass B) bandpass C) noisy D) noiseless

Answer 33

D

Question 34

. In a frequency-domain plot, the horizontal axis measures the ________. A) phase B) frequency C) slope D) peak amplitude

Answer 34

B