Final Exam Information for the 135b PRACTICAL

Location	Regular lab room
Date & Time	Week of April 17, 1999 at your regular lab time

Format: 1/2 the people will show up for the first half of lab and the remaining 1/2 will show up for the 2nd half of their regular lab time. The breakdown is ACCORDING TO YOUR LAST NAME and is as follows:

• What's it going to be like?
• What should I know?
• What should I bring?

1. The exam will be held during the regular class time.
2. No lab manuals or answer books will be allowed during the exam.
3. Measurements will be performed individually (no partners).
4. The same three questions will be given to everybody, but you will only need to do two total - One for each of the two parts.
5. Each question is 30 minutes long and consists of an experimental part with various questions. You must do question 1 for the first part. For the second part, you are given a choice between question 2 or question 3. Do not do both! If you do both, then you will be given the lower score of the two.
6. Show all work and include all units. If you run out of room, use the back side of the preceding page and indicate your work is there.
7. You are not allowed to practice for this exam during the make-up day.
8. Time saved during one question of the exam can not be transferred to another. Instead, use the extra time to check your answers and prepare for the other questions.
9. Allowed time - 60 min., 30 min. per question. This time can be stretched up to a total of 70-80 min. if necessary (decided by the TA); however, your score might be affected in this case.
10. Advice: The TA might offer to trade some of your points for a hint. When you are seriously stuck, this might be a very good deal.

• Don't worry so much about memorizing procedures! The practical will be like a mini-lab; there'll be instructions telling you to take a measurement of this or a reading of that and all you have to know is how to use the equipment to carry out each instruction. You'll also be expected to know basic formulas (don't worry, nothing too funky).
• You'll have to work solo this time (i.e., no partners) and will be expected to do the procedure on your own. If you request help from the TA (i.e., yours truly), you'll lose a certain number of points for each request (see item 10 above for all the gory details).
• You will be given 30 minutes to do each experiment. If you get done early, please come to me as I might let you start on the next experiment early if all is in order.
• Please remember that you are responsible for only TWO experiments! So don't go around doing the 3rd guy and expecting any kind of extra credit for it (in fact, did you read item 5 above??).
• After you do the first experiment, I'll briefly check your lab report and then tell you to get started on your next (and very last!) experiment. After the end of the final, your lab reports will be collected and graded in detail by me. But once you've handed in your final lab report you are DONE with the Physics 135b Laboratory forevermore!!!

Part I. Mandatory Question -- you will be asked to build a circuit using the following

• Kirchoff board with various components.
• Power Supply

You will then measure V and I of the various components using a Keithley Multimeter to get the most precise value you can. You need to know Kirchoff's Laws, Ohm's Law, and Power in addition to using the equipment.

Part II. Optional Questions 1 & 2 (pick 1 of 2) -- in each, you will be asked to build a circuit using the following:

• Function Generator
• Circuit Board with various components.

You must know how to use the function generator to set it to a particular type of wave. You will then be asked to use the Oscilloscope to interpret input signals such as period, frequency, and voltage on the function generator and the circuit, being as precise as possible. You must know the rules governing AC circuits.

• First and foremost, get familiar with the questions (as described above!). That means you should make sure you understand what the questions are asking you and what all the terms mean. If you're at all unsure of any term, grab your copy of Giancoli and start scanning the index for that term. Make very sure you understand what the question is asking before you come to the practical. If you have any doubts about either of these questions, drop me a line at rickys@sethi.org.
• Make sure you're comfortable with your lab manual and the equipment that you need to use for each experiment (at the very least, make sure you can recognize the equipment, and the formula(!), when you see it). In terms of this, the specific labs that I'd recommend reviewing are Labs 3-5; the reason for this is that the first lab presented information which you should all have burned on your brains (if any of Lab 1 seemed like some strange dialect of Greek, just put the beer down, and start re-reading it!). Lab 2, mapping the electrostatic field, is nice but totally unrelated to any of the lab practical questions (above). Also, you might want to check the review notes on labs 1-5 by clicking on the midterm review link to the left.
  • Lab 3 is an important one; obviously, Part I above is pretty much based on this. So make sure you know all the basics from Lab 1. Make sure you know the basic laws: Ohm's, Kirchoff's, etc. (pp. 25-28 in your lab manual). Review the basics of ohmic/non-ohmic materials (p. 24). Check the procedure section and especially make sure you remember how you measured the current and voltage in Section 4.4 (I'd recommend dusting off your lab answer manual and seeing any notes you might have made in there). Finally, don't overlook that Appendix A (p. 35) and make sure you know how you read the colour codes for resistors.
  • Lab 4 is the other really major one I'd spend some time with; grab yourself some coffee and curl up on a nice, comfy couch with your lab manual for this one. Both questions in part II call upon all the skills you learned in this lab.
    
    For the experimental aspect, know the basics of your AC power source (what was your AC power source? See p. 61), the basics of your oscilloscope (especially review pp. 45-46 in your lab manual where you carried out various manipulations on the V/div, time/div, vertical position, etc. knobs and what aspect of the wave they affected; how do you know which channel(s) you're currently looking at (see item 10 on p. 54)? what does the beam find button do? etc.), and the AC settings on your multimeter.
    
    For the theoretical part, make sure you know all about peak-to-peak vs. peak value; how are the rms values related to the peak value (see EQ 1 on p. 39); does this relationship apply for all kinds of waves or only a specific kind? Which of these does your multimeter read? Read pp. 37-39 for this stuff. Finally, make sure you review what the diode does and how it works (p. 41 and the questions on p. 52).
    
    Another great review for this is Figure 9 on p. 49: how'd you carry out all those measurements? What manipulations did you have to do on the oscilloscope or the function generator to carry them out? How did you place your multimeter (and where) to measure the current or voltage in the various parts of the circuit (check your lab answer book for this!)? Finally, review p. 53 and know how that circuit acts like a low-pass filter (see the lab notes for this lab for more on this).
  • Lab 5: speaking of filters, you might want to review this lab and see if you can recognize how the filters did what they did. I'd mainly concentrate on the theory and the results for this section. As always, please remember that these recommendations are just the result of my feverish imagination; the best and most comprehensive review will be the one that your own promptings guide you to!
• Make sure you review all the formulas and understand what is what in the main ones enough to be able to use them (e.g., does the V_rms in the AC Circuits experiment apply to the square wave? Why or why not? How can you compute the V_rms? Does your multimeter read V_o or V_rms? etc.)
• Remember to keep track of units during any calculations; perform unit conversions with care and keep an eye out for order of magnitude errors (e.g., if you start to get an current of 10⁶Amps for any measurement, there must've been some problem along the way (maybe you used millimeters instead of meters, is your multimeter set to milliAmps or Amps, is your lead plugged in the mA plug or the A plug (or in the V/W plug), etc.))
• Finally, if things start go terribly awry, just relax! You've done all the experiments before and the data isn't nearly so important as how you analyze and interpret it. Even if you get the "wrong answers", find a reason why things went wrong and explain how you might fix it in your conclusion (remember, your reasoning and conclusions are at least as important as just getting the "right" answer).

1. Just about all you should need is your calculator.
2. A ruler or straight-edge, if you have an extra one lying around.
3. Bring some blank sheets if you think you might want to derive Schroedinger's equation in-between experiments (or if you just write big).