Cuesta College, San Luis Obispo, CA
Cf. Giambattista/Richardson/Richardson, Physics, 2/e, Example 20.1, Problem 20.1

Solution and grading rubric:
- p:
Correct. Applies Faraday's (and Lenz's) law to the changing/constant external magnetic flux through the loops: the upwards moving loop has a changing (decreasing) external magnetic flux through it, so it will have an induced current in it; while the loop moving to the right will have a constant external magnetic flux, so there is not induced current in it. Or may argue using right-hand rule 1 to show that the upwards loop will have a net clockwise current due to the magnetic force on fictitious positive charges in its bottom section, while the loop moving to the right will not have a net current due to the magnetic force on the fictitious positive charges on its side sections both pointing upwards. - r:
As (p), but argument indirectly, weakly, or only by definition supports the statement to be proven, or has minor inconsistencies or loopholes. - t:
Nearly correct, but argument has conceptual errors, or is incomplete. - v:
Limited relevant discussion of supporting evidence of at least some merit, but in an inconsistent or unclear manner. Some attempt at using right-hand rules, magnetic fields, forces, currents, flux, Faraday's (and Lenz's) law, induced emf and induced current. - x:
Implementation of ideas, but credit given for effort rather than merit. - y:
Irrelevant discussion/effectively blank. - z:
Blank.
Sections 30882, 30883
Exam code: midterm02iF47
p: 27 students
r: 7 students
t: 5 students
v: 1 student
x: 0 students
y: 0 students
z: 0 students
A sample "p" response (from student 0007), with a graphical approach to Faraday's and Lenz's laws:

Another sample "p" response (from student 7979), instead discussing the effect of magnetic forces on the fictitious positive charges in the loops:

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