Question 1.(TCO 1) A sinusoidal signal has an amplitude of 10, frequency of 2 Hz, and initial phase of 60 degrees. It passes through an LTI system and undergoes a gain of 3.5 and a 60-degree phase lag. The resulting output signal will be mathematically described as (Points : 10)

35 sin(4t + 2π/3).

35 sin(4πt – π/3).

35 sin(4πt).

3.5 sin(4πt – π/3).

3. (TCO 2) An RLC circuit, with an initial voltage across the capacitor and polarity as marked on the circuit, is shown below. The switch is closed at t = 0 and a current i(t) is assumed to flow clockwise in the circuit. Determine which expression correctly represents the Laplace-transformed value of current, i(s). Note that the coefficient of the highest power of s in the denominator may have to be made unity.

5. (TCO 4) A signal consists of only two sinusoids, one of 35 Hz and one of 45 Hz. This signal is sampled at a rate of 230 Hz. Find the first six positive frequencies that will be present in the replicated spectrum. (Points : 10)

35, 45, 185, 195, 265, 275

35, 45, 195, 205, 265, 275

35, 45, 185, 195, 275, 285

35, 45, 185, 195, 265, 295

6. (TCO 4) A discrete signal or sequence is given in a table below as a function of n or a sample number. All values not shown can be assumed to be zero. Find the z-transform of the signal. Hint: Use the basic definition of z-transform

- 7. (TCO 4) A system samples a sinusoid of frequency 1,070 Hz at a rate of 545 Hz and writes the sampled signal to its output without further modification. Determine the frequency that the sampling system will generate in its output. (Points : 10)

20

645

525

1,070

Question 8.(TCO 4) A signal has a spectrum from 0–250 Hz as shown below. It is sampled at a rate of 375 Hz. Find the region of the baseband spectrum that will become corrupted and unrecoverable even if an ideal “brickwall” filter is used for recovery.

of a periodic sequence with digital period of 4 if the first four terms of the sequence are given by 4, 4, 2, 3. (Points : 15)

Question 1. (TCO 7) If our sampling rate is fixed, how can we make the resolution of Fourier transform finer (i.e., be able to resolve frequencies in spectrum that are closer together)? (Points : 10)

Question 2. (TCO 1) Does a sine wave have odd symmetry or even symmetry, and why? (Points : 10)

Question 3.(TCO 1) What are the four basic or fundamental signals, and why are they so important? (Points : 10)

Question 4.(TCO 2) A series RC circuit is shown below. When the switch is closed, permitting a flow of current in the circuit, will the waveform of voltage rise across the capacitor consist of (a) an impulse, (b) a step, (c) a sinusoid, or (d) an exponential? Why or why not? Briefly justify your answer.

Question 5. (TCO 3) Given the transfer function of a continuous system (i.e., TF is in Laplace or s domain) describe, in a general form, the steps you have to take to find the output in time domain, for any given arbitrary input described in time domain. (Points : 10)

Question 6.(TCO 4) What is the fundamental difference between the spectrum of the same signal before and after the signal is sampled? (Points : 10)

Question 7.(TCOs 5 and 6) What is meant by the delaying property of z-transform? How does the delaying property of z-transform help us obtain the transfer function of a system from its difference equation? (Points : 10)

Please click on the “PURCHASE” link below to get “ECET 345 Final Exam Answer”.

For instant digital download of the above solution or tutorial, please click on the below link and make an instant purchase. You will be guided to the PAYPAL Standard payment page wherein you can pay and you will receive an email immediately with a download link.

In case you find any problem in getting the download link or downloading the tutorial, please send us an email on ekmtutor@gmail.com.