<p>Mechanics is significantly easier than E&M. Typically in mechanics problems you can follow standard steps to solve the problem. In E&M, you can think you know the steps and still not understand how to do the problem. Except for very straight forward problems, the steps to solving them isn't obvious.</p>
<p>Some professors give exams harder than the homework, but many do not. Its just that in E&M, a lot of the students can't even do the homework, many times because they don't have a good understanding of the necessary math tools.</p>
<p>Haha oh dear okay so how do we solve this? Is it the induced electromagnetic force? F=BIL? But the question seems odd. Somebody please solve it! (:</p>
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Do professors purposely offer problem sets that don't prepare you appropriately for the test? I don't understand how a test can come off as "just so crazy" when students have (presumably) studied hard.
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<p>I agree with all of the posters above about why an exam can be "just so crazy", after you've studied hard. I think people who have the best transition to college engineering courses are those that focus on understanding the material in high school. When I was in high school, I was the guy with the neat handwriting, the guy who checked his homework and exams twice or 3 times for mistakes before turning it in. Needless to say, at the high school level, it was a breeze because those things matter.</p>
<p>However, in college level physics/engineering courses, the keywords are "speed" and "application", everybody understand the basic concepts, just because your handwriting is nice or your calculations are correct, will not give you a single point on the exam if you are applying the wrong concepts. On the other hand, if you are applying the concepts right, but your answer is off, you will get many points, if not most points. Another thing I had difficulty with, is answering a question in a parallel fashion, when you have multiple unknowns, you really need to think fast and clearly, if you choose the wrong approach, guess what? that entire problem is a big fat zero for you. (Most of my mechanics classes had 3-4 main problems, so there goes 25% of your grade)</p>
<p>So, to me the biggest difference between high school and college engineering/math/physics is partial understanding vs. total understanding, that's a huge leap.</p>
<p>(From a physics exam at Rice) A 10-turn wire loop measuring 8.0 cm by 16.0 cm carrying a current of 2.0 A lies in the horizontal plane and is free to rotate about a horizontal axis through its center. A 50-g mass hangs from one side of the loop. A uniform horizontal magnetic field is also present, parallel to the horizontal plane. What magnetic field strength is required to hold the loop in its horizontal position?</p>
<p>PHYS102 - Tests - Rice University</p>
<p>Sorry it was this^ question. Btw, how do you reply to someone's post? I'm kinda new at this and I thought checking the box after clicking 'reply' on someone's post would do it but apparently not.</p>
<p>Since I'm not certain what this is for, I won't directly answer the question. However, I would start to think about torques on this loop, and the fact that the current is going in opposite directions in opposite sides. Obviously you only need to worry about the z components (perpendicular to the loop plane)</p>