Comments about grading of reading quiz from Friday, Feb 2, 2001
A lot of people got question 1 partially wrong:
1. Which statement(s) is(are) true? Ohm's Law:
The only correct answer is (c). In particular, many people wrote down
Ohm's law (V=IR) but incorrectly concluded that this implies that current
is proportional to resistance. In fact, rearranging we get V/I = R which
means that current is inversely proportional to resistance.
Given that this seems like a mistaken interpretation of "proportional"
I am giving credit for answer (e), and extra credit for answer (c). But,
note that answer (e) is in fact wrong.
- a. Asserts that the current in a conducting wire is proportional to the
resistance of the wire
- b. Is a general law of nature like Newton's Laws and Coulomb's Laws
- c. Describes the electrical properties of some conducting materials
- d. All of the above are correct
- e. Two of the above are correct
The answer to question 2 is: two identical resistors have a
larger net resistance if they are connected in series, than if they
are connected in parallel (answer a)
The answer to the third question is answer b, electromotive force (measured in
volts); current is measured in Amps (coulombs/s) and resistance