Physics 121: Final Exam Study Guide

Winter Term, 2012

The final exam will cover lecture and lab material from the entire
course. But **don't panic**! Though the course content is extremely
broad, this study guide will focus your attention on the relevant pieces
you need to retain for the final. The final will be drawn from the items
below, so this guide is highly relevant.

- Be aware of how to make a machine drawing. If I give you a physical
description of part, along with a 3-D sketch, be able to draw the relevant
projections (ANSI std) and apply the relevant dimensions so that a
machinist—given
*your*drawings alone— could make the part. - Understand how to manipulate the stress-strain relationship, so that you could calculate how much a beam will compress or stretch under a load applied along the length. Also know how to utilize a moment of inertia so that when coupled with a (given) formula for beam deflection, you can calculate the amount of deflection a particular beam will experience.
- Understand how to calculate the three forms of heat flow given
parameters such as area, temperature, emissivity, thermal conductivity,
convection
*h*-parameter, etc. Given a box with a known power load inside, you should be able to calculate the (approximate) temperature rise inside the box given full knowledge of the box parameters: as you did for the third lab. - Be able to trace rays through thin lens systems, following the rules we went over in class.
- Be able to use the lens-maker's formula and the Gaussian lens formula in simple optical applications.
- Be able to draw, from scratch, an AC-to-DC power supply of the type you built in Lab 6. This will include a center-tapped transformer, four diodes, two big capacitors, voltage regulators, and load resistors. You will be asked to design a dual power supply that can handle a certain load (in milli-amps). Be able to calculate the capacitor needed to stay safely above the regulated voltage (up to you to know how much overhead to provide) given a peak-to-peak figure for the transformer sine wave.
- Be able to follow the simple rules of op-amp negative-feedback operation so that you can design an inverting amplifier, a non-inverting amplifier (follower with gain), or a summing amplifier. The flip side of this is being able to dissect an op-amp circuit and figure out what it does.
- Understand digital logic and be able to evaluate an arrangement of logic gates. You'll want to know the logic tables for AND, OR, XOR, and their inverted (NAND, NOR, XNOR) siblings. I'll provide help on identifying the symbols, but you should remember the logic tables. Luckily, the words give a substantial clue.
- Be able to jot down some C-code that will
**take a command line argument**, cycle through a loop of ten values, perform some mathematical manipulation (to be specified) for each cycle in the loop, printing the result to screen for the user to see. If you're smart, you'll make up such a code now and test it, so you know you have a winner. Past experience says about half the students are smart enough to heed this advice.*Which half are you in?* - Know how asynchronous RS-232 serial packets are composed, so that if I give you a hexadecimal number (or a bit stream as from the card reader), you can convert this into an RS-232 asynchronous frame (packet) with the correct voltage levels, and according to the parameters (such as 7E1 at 9600 or 8N1 at 1200, etc.).