Physics 8B Midterm 1 - Zettl

Colleges & Universities University of California - Berkeley
1

<p>did Zettl say anything else in class on Tuesday about the midterm tonight? i skipped Lecture to study for this -_-'</p>

2

<p>no no futher details were given
its gonna be hard</p>

3

<p>how do you know? =/</p>

4

<p>i gotta feeling
that tonights gonna be</p>

<p>…you know the rest</p>

5

<p>whoa, you were right SB.</p>

6

<p>sadly i was</p>

7

<p>btw was the last one postiive voltage?</p>

8

<p>i got negative, pretty sure i’m right for that one</p>

9

<p>but as the bar moves rightward, the area decreases, by lenzs law you want to counter that change and current flows in same direction making positive voltage</p>

<p>right?</p>

10

<p>well flux is going into the page, so moving right decreases flux that is going into the page.</p>

<p>this means a current will be induced that causes flux into the page to increases, which = increase of magnetic field into the page.</p>

<p>this means current flows Clockwise.</p>

<p>since current flows from positive terminal to negative terminal, this means point B will be at a higher potential than A. B is the “positive terminal” then.</p>

<p>since zettl defined a positive terminal at A as registering a positive voltage on the voltmeter, if B is the positive terminal the voltmeter should register a negative voltage.</p>

11

<p>A was on top…</p>

<p>so current flows CW from A to B. hence voltage is positive at A and negative at B.
And I’m sure that this is right (also confirmed with GSI).</p>

12

<p>hm yeah that makes sense now that i think about it, crap. hopefully i get some partial credit on it…</p>

13

<p>wait, solutions are up at bspace and it says negative. YES!</p>

14

<p>looks like i got the Capacitor energy one wrong and also like half of #5 wrong. everything else looks okay tho…</p>

<p>just added up my score, looks like i got perhaps an 80-85% or so? meh, not bad considering.</p>

15

<p>anyone get these back yet?</p>

16

<p>The grade distribution is up on bspace… It doesn’t look too bad!</p>

17

<p>average was 55%… it looks horrible LOL</p>

18

<p>look at the average for bordel!</p>

19

<p>looks like she had an easier test looking at her histogram. i guess that’s good for us though, we get more of a bump…</p>

20

<p>Oh haha I meant it probably would’ve worked in favor of us. Reading your responses, it looked like you got a good number of questions right to get a score that’s well above average.</p>