QUESTION 15

15. Select the correct equation that represents an AM signal.

		a. s(t) = Ac[1 + AM cos (2fmt)] cos (2fct)
		b. s(t) = Ac cos [2fct + FM *sin(2fmt)]
		c. s(t) = Ac cos [2fct + p cos (2fmt)]
		d. c(t) = Ac cos (2fct )

10 points

QUESTION 16

16. Select the correct equation that represents an FM signal.

		a. s(t) = Ac[1 + AM cos (2fmt)] cos (2fct)
		b. s(t) = Ac cos [2fct + FM *sin(2fmt)]
		c. s(t) = Ac cos [2fct + p cos (2fmt)]
		d. c(t) = Ac cos (2fct )

10 points

QUESTION 17

17. Select the correct equation that represents an PM signal.

		a. s(t) = Ac[1 + AM cos (2fmt)] cos (2fct)
		b. s(t) = Ac cos [2fct + FM *sin(2fmt)]
		c. s(t) = Ac cos [2fct + p cos (2fmt)]
		d. c(t) = Ac cos (2fct )

10 points

QUESTION 18

The period of a sinusoidal waveform is T = 1E-3 = 1 x 10^-3 seconds. What is the frequency and wavelength of the waveform?

		a. 1 Hz, 3E8 meters
		b. 1 kHz, 3E5 meters
		c. 1 MHz, 300 meters
		d. 1 GHz, 0.3 meters

10 points

QUESTION 19

19. If the AM Index, , is between 0 and 1, the distortion of the signal will be minimized.

True

False

10 points

QUESTION 20

A voltage controlled oscillator (Vco) is used to convert message amplitudes into carrier frequency changes.

True

False

10 points

QUESTION 21

21. Select the correct statement(s) regarding QAM.

		a. QAM consists of two carriers operating at the same frequency
		b. Using QAM, information is captured on the carrier(s) in the form of amplitude and phase shifts
		c. QAM with M=8 can represent 3 bits per symbol
		d. All of the above are correct

10 points

QUESTION 22

What does the FM Modulation Index, , tell us.

		a. How much the phase of the carrier frequency is allowed to change
		b. What the phase of the message signal is in relation to the carrier frequency
		c. How much the carrier frequency is allowed to deviate from center
		d. All of the above

10 points

QUESTION 23

23. Calculate the data rate for a 1200 baud signal where each symbol can take on one of two levels (M=8)

		a. 2400 bps
		b. 4800 bps
		c. 3600 bps
		d. 9600 kbps

10 points

QUESTION 24

A symbol can take on one of 64 signaling levels. How many bits can be represented by a single symbol?

		a. N=2
		b. N=4
		c. N=6
		d. N=8

10 points

QUESTION 25

Given the following AM signal, determine the carrier wave's amplitude (Ac) and frequency (fc), the message signals frequency (fm), and the modulation index (): s(t) = 3[1 + 0.6cos (2100E3Hz*t)] cos (21E9Hz*t)

		a. Ac=3, fc=100kHz, fm=1GHz, =0.6
		b. Ac=3, fc=1GHz, fm=100kHz, =0.6
		c. Ac=0.5, fc=1GHz, fm=100kHz, =6
		d. Ac=0.5, fc=1GHz, fm=2kHz, =6

10 points

QUESTION 26

Given the following equation for an FM signal, select the correct information below:

s_FM(t) =3cos[(2280khz*t)+3sin(24000Hz*t)], k_VCO=2000(Hz/v)

		a. FM Index, =9, Message Amplitude, Am=3v
		b. FM Index, =3, Message Amplitude, Am=6v
		c. FM Index, =3, Message Amplitude, Am=3v
		d. FM Index, =9, Message Amplitude, Am=6v

10 points

QUESTION 27

Determine your FM bandwidth given the following: FM Index =5, frequency of your message is fm-4000Hz.

		a. 4 kHz
		b. 12 kHz
		c. 24 kHz
		d. 48 kHz

10 points

QUESTION 28

Given the following equation for an PM signal, select the correct information below:

s_PM(t) =3 cos[(2300MHz*t+5cos(24kHz*t)], k_P=0.3

		a. PM Index, p=5, Message Amplitude, Am=16.67v
		b. PM Index, p=6, Message Amplitude, Am=16.67v
		c. PM Index, p=3, Message Amplitude, Am=6v
		d. PM Index, p=6, Message Amplitude, Am=5v

10 points

QUESTION 29

With PM, the message amplitude and frequency are directly related to bandwidth.

True

False

10 points

QUESTION 30

When frequency division multiplexing (FDM) is used, guard channels are NOT required in-between frequency channels.

True

False