Reading:

Cutnell and Johnson, Chapter 21 -- 21.7 .

Problems for Review:

Reviewing these problems gives you good exposure to this week's main topics, in practice. All are worked in the Student Study Guide [SSG] or Student Solutions Manual [SSM]; solutions are posted on our website http://www.physics.emory.edu/Classes/142-003.html , for those without these texts.

Conceptual:

MCAT review problem, [SSG] p 414.

Quantitative:

Chapter 21, problems 5, 9, 13, 33, 37, 41, 45, 57, 61, 77.

Problems to Hand In:

Conceptual:

Use the following to answer questions 1--6:

1. In what direction does the current flow through the loop?
   1. clockwise
   2. counterclockwise
   3. current alternates between clockwise and counterclockwise
   4. impossible to determine from the information given
2. What is the magnetic moment of the loop?
   1. 0.20 A , directed into the page
   2. 0.20 A , directed out of the page
   3. 0.63 A , directed into the page
   4. 0.63 A , directed out of the page
3. A weak bar magnet is placed at the center of the current loop. Which way will it align?
   1. Horizontally, with the north pole pointing to the right.
   2. Horizontally, with the north pole pointing into the paper.
   3. Horizontally, with the north pole pointing out of the paper.
   4. Vertically, with the north pole pointing up.
4. A straight wire, with current flowing directly into the page, is placed at the center of the current loop. What magnetic force with the current loop exert on the wire?
   1. None.
   2. A nonzero force, directed into the paper.
   3. A nonzero force, directed up.
   4. A nonzero force, directed to the right.
5. It is desired to cancel the magnetic field at the center of the loop by placing a straight, current-carrying wire at an appropriate distance from the loop. Which of the following configurations could possibly yield zero magnetic field at the loop's center?
   1. A straight horizontal wire with positive current flowing into the page, located to the left of the current loop
   2. A straight vertical wire with positive current flowing up, located to the right of the current loop
   3. A straight vertical wire with positive current flowing up, located to the left of the current loop
   4. both (b) and (c)
6. A current ``miniloop,'' with radius 0.01 m, current 1 amp, and magnetic moment , is placed at the center of the above current loop. Which is an accurate statement about the torque exerted on the miniloop?
   1. A torque of up to Nm acts to align the miniloop. The aligned miniloop lies in the same plane as the large loop, with both currents flowing in the same direction.
   2. A torque of up to Nm acts to align the miniloop.The aligned miniloop lies in the same plane as the large loop, with both currents flowing in the same direction.
   3. A torque of up to Nm acts to align the miniloop. The aligned miniloop lies in the same plane as the large loop, with both currents flowing in opposite directions.
   4. None of the above.

Quantitative:

Chapter 21, problems 2, 8, 14, 22, 28, 30, 44, 56, 76.

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