EE 2212

PROBLEM SET 1

S. G. Burns

Due: 24 September (Friday) 2021

Ø I will collect the problem set when I collect the associated quiz. It is also important to note that I often use homework problems as part of the weekly quizzes. Some or all of the problems on each problem set will be graded. Quiz coverage will include material related to, and supporting the problem set as well as material covered in class through the previous class period. Any additions or deletions from quiz topical coverage will be announced in class, via e-mail, and/or on the class WEB page. I strongly encourage you to ask questions about the homework problems during our ZOOM class and during ZOOM office visits. I also encourage you to ask for assistance on any underlying and supporting topics from other courses. You may work together virtually or if face-to-face if you obey all CDC and UMD guidelines and COVID protocols, and I encourage you to do so, but remember you, and you alone, are responsible for your work and you must turn in homework individually unless otherwise noted. Material from laboratories may also be incorporated in the quiz.

Ø ALL QUIZZES are open book and notes. Laptops and tablets are OK, also WEB access. Be careful on time management when using the WEB during the quiz time. Be sure and bring your completed problem set to class.

Ø QUIZ 1, nominally 25 minutes long, will be given on Friday, 24 September, during the last portion of the class period.

Ø Please keep your video and audio ON during the quiz. You will have until 15 minutes after the class ends (12:05 pm) to scan/image/pdf and send as an-email attachment to sburns@d.umn.edu Be sure your submission is readable!!!

Ø Also, take the opportunity to study the text "Examples", which includes solutions.

Ø I also encourage that you read the Preface in the text to provide a broad perspective on what topics are included in the text.

Ø Be aware that you may often use different approximations and approaches to the problem solution which may result in somewhat different (but very correct) answers. Apply your skills in engineering to evaluate the correctness of your answer and solution method should there be a perceived discrepancy. One of my favorite expressions is, “Look at you results with an engineering eye”.

Ø I use a mix of text problems, expansions and additions to text problems, problems I have generated, and old quiz problems. I am well aware that text solution manuals can be found on the WEB free or for a price. Be careful on using WEB sources since they may refer to different text printing dates and there are often errors and different approximations used. Trust yourself on solving the homework problems.

Ø You will need and use SPICE/PSPICE in EE 2212.

Ø One other very important issue which you should be aware of. I use SYMBOL font in MSWORD, and ADOBE fonts, as needed, in preparing WEB documents. I also use IE (Internet Explorer) and Chrome as my WEB browser. One reason I use MS WORD and IE and Chrome is that they are available through ITSS and are supported by UMD. There are cases where your personal generic WEB browser and word processing program may not interpret SYMBOL and ADOBE font correctly. This is especially true for “shareware” and non-standard versions of word processing programs, including Open Office, and versions of some operating systems such as Firefox. Safari (Apple computers and the iPAD) also has some issues. For example the Greek Omega symbol for ohms which should print out as the Greek symbol Ω could print out as a W. This would occur if your printer driver and/or word processing and/or font utility within your WEB browser were not set up to accept SYMBOL, or in some cases ADOBE fonts. To the best of my knowledge, all the EE computers using IE and MS products and printers are OK but your personal system may not be. Please let me know if you have this difficulty so I can try and work on fixes with you.

Ø You will follow the same procedure when submitting homework. Your homework solutions(scan/imaged) should be sent as e-mail attachments to sburns@d.umn.edu

Ø by 12:15.

Now several problems in review of circuit analysis techniques from EE 2006. If any of the basic circuit concepts from EE 2006 are a bit rusty, please ask questions during class or stop by and ZOOM with me. Also note that

1. Text 1.21 and Text 1.24. Some plug-and-chug practice with Ohm’s Law with an input independent voltage source. Solve the problem symbolically. That is you need not plug in numbers, however, generate a Thevanin equivalent circuit for each circuit.

So far you have solved Problem 1 with independent voltage and current sources. The next problem addresses dependent sources. This problem includes independent voltage and current sources , and dependent current generators. Derive an expression for the Thevanin equivalent circuits at the indicated nodes.

2. Text 1.27 both circuits. Use symbolic notation; that is do not substitute numerical values for the circuit elements; use the element names such as R₁, g_m, etc. Do not provide numerical solutions.

The next two problems review review of some EE 1315 concepts. If any of the basic concepts from EE 1315 are a bit rusty, please ask questions either during class or set up a ZOOM office visit.

3. This is a block diagram of a 4-bit analog to digital converter (A/D). Assume the analog input ranges from 0 to 10.0 volts. Fill in the conversion table for the A/D converter. Note that most, but not all, consumer applications use 8-bit A/D and D/A conversions.

Digital Output	Analog Input in Volts
0000	0.0
0001
0010
0011
0100
0101
0110
0111
1000
1001
1010
1011
1100
1101
1110
1111	10.0

4. Note that 8 bits/color (red, green, or blue), often called 24 bit color for marketing obfuscation, is typically used for displays, cameras, and printers. Add the following: For example, your smart phone or laptop display typically uses three colors-red, green, and blue. If each color is digitized with 8-bit resolution, how many different colors can be displayed? What is your opinion on whether the human eye can differentiate this number of colors? Repeat for 10 bit/color resolution now advertised) for some high end Samsung and LG monitors/televisions

5. Write peak and rms phasor notation (cosine reference) expressions for the following signals. Sketch the resulting phasor on the complex plane at t=0.

(a) V₁(t) = 100 cos (1000 t + 30°)

(b) V₂(t) = 100 cos (1000 t) + 100 cos (1000 t + 45°)

(c) V₃(t) = 200 cos (1000 t) + 100 cos (500 t + 45°) Be careful! Explain why Part (c) is a trick question. At least I warn you sometimes about trick questions!

Now write the time domain function, assuming 60 Hz operation for the following rms phasors; repeat if these two expressions are peak phasors. Reminder that ω = 2πf.

(d) V_a = 200Ð30°

(e) V_b = 200

6. 6. Fill in the following table

66

7. Let’s think about electrocution!!! You were out partying with one of your electrical engineering student friends (Best Friend Forever-BFF) from an unnamed large university located in the Twin Cities. Towards the end of the party, your “BFF” thought he was doing you a favor and wired up a standard duplex outlet for your apartment. Unfortunately, besides not doing well in the large unnamed university in the Twin Cities equivalent to the UMD EE 2006 circuits course, and under the influence of a large quantity of your, probably not legal, beverage offerings, your “BFF” did not follow the National Electric Code. (U.S. standards) when “helping” wiring your apartment Your “BFF”(?), made four errors, three of which could potentially electrocute you!

(a) Describe the four errors and explain how you must fix them. You can mark up the diagram appropriately or provide a separate series of diagrams.

(b) Identify the three potentially fatal errors and explain why they could lead to your electrocution (Be sure your tuition is paid up).

(c) Your friend, who will probably get an F in their circuits class, decides to demonstrate his

circuits class knowledge by plugging in a lamp. Will the lamp work? (YES, NO, PARTIAL INTENSITY, EXPLODE) Circle your choice and explain your answer.

8. Text 10.2 Plug-and-Chug Parts (a) and (c) only.  This will help you in Experiments 2 through 4.  Be sure you note the difference between ln(X) and log₁₀(X) when you do the calculations.  i.e.  Punch the correct calculator buttons/icons!

9. You decide to have a loud noisy  party this Labor Day weekend with great music instead of studying EE 2212 and working on Problem Set 1 or at least delay your studying until you recover.  Suppose your 300 watt sound  system yields an 80 dB signal as measured by the police in response to a noise ordinance complaint by a neighbor who you should have  invited to your party.        http://www.industrialnoisecontrol.com/comparative-noise-examples.htm

       (a) If the noise ordinance limit is supposed to be 65 dB at the lot line, at what power level should you run your system? 

        (b) Suppose you suggest to the police , politely of course,  so that you can avoid getting a minor for other possible infractions at your  party,   that the noise measurement be taken further away than the lot line.  As an engineering student doing well in EE 2212, how much further away should the noise measurement be taken?  You may assume that measured audio power is   proportional  to 1/r² where r is the distance from your speakers to the point of measurement.  Your answer will be a distance ratio.

   Many municipalities  prohibit sustained noise that exceeds a certain decibel level.    The decibel limits are set according to the time of day and the neighborhood zoning.     When a neighbor complains, police place decibel level monitoring equipment on an estimated property line and take a reading. https://www.pca.state.mn.us/sites/default/files/p-gen6-01.pdf

Now for the important stuff from my extensive files of stuff. I hope you can handle it without getting sick

Sort of refers to Text Figure 1.5

We will discuss electrocution. Refer to Problem 7.

Math is important! Basic EE 2006 Material.

We have cats! Please do your homework on time!!!

Units are important!!! FYI, lithotripsy is the non-invasive medical procedure to break up kidney stones

COVID Could drive you to this.

Good advice for homework solutions and lab reports!!!