1. All signals that contain information/messages have an associated frequency bandwidth. Therefore, viewing the signal in both the time and frequency domains is critical.

True

False

2. A carrier wave is used to shift a baseband signal to a higher frequency for transmission. This process is called modulation, and results in the creation of a passband.

True

False

QUESTION 3

Select the correct statement(s) regarding modulation.

		a. a receiver tunes into a modulated carrier signal, and recovers the original message (i.e., baseband) through a demodulation process
		b. a carrier that has been modulated by a message (i.e., baseband) will have an associated frequency bandwidth
		c. demodulation is a process where the baseband signal is recovered from the passband
		d. all statements are correct

QUESTION 4

A carrier wave has an amplitude of 2.5 volts, a frequency of 125 kHz, and zero phase angle. Select the correct carrier wave equation.

		a. c(t) = 5 cos(2*125*t + 0)
		b. c(t) = 125 cos(2*2.5*t + 0)
		c. c(t) = 2.5 cos(2*125E3*t + 0)
		d. None of the above are correct

QUESTION 5Select the correct statement(s) regarding amplitude modulation (AM).

		a. If the AM Index is greater than 1 (i.e., AM>1), then over modulation occurs leading to signal distortion
		b. With AM, the message is captured as amplitude changes to the carriers amplitude.
		c. The AM modulated signal bandwidth is dependent upon the highest frequency (fm), and frequency bandwidth, of the message
		d. All of the above are correct

QUESTION 6

1. Amplitude Modulation (AM) describes a method where the baseband message is represented by carriers frequency.

True

False

QUESTION 7

Select the true statement regarding Amplitude Modulation (AM).

		a. An increase in message amplitude, Am, results in a higher AM Index, AM.
		b. An increase in message amplitude, Am, results in an increase in occupied frequency bandwidth.
		c. As the message frequency increases, the occupied frequency bandwidth decreases.
		d. Over-modulation occurs when the carrier wave amplitude, Ac, is greater than the message wave amplitude, Am.

QUESTION 8

1. Given the following parameters, select the correct equation for the modulated carrier signal. A_m=3v, A_c=3v, f_m=5500Hz, f_c=100MHz, _m=0, _c=0

		a. s(t) = 3[1+1.08 cos(25500t)] cos(2100E6t)
		b.s(t) = 3[1+1cos(25500t)] cos(2100E6t)
		c.s(t) = 3[1+6.5 cos(23500t)] cos(2100t)
		d. s(t) = 6.5[1+0.93 cos(2100t)] cos(2100E3t)