Unit 4: Magnetism and Electromagnetism
Physics 2 · Unit 4 · Paper 3

Magnetism and Electromagnetism unit test

A test on this unit alone, marked as a percentage and a letter grade — for the test your class is actually sitting, rather than for May. Answer everything, then submit once: seeing the answer to question 3 before attempting question 4 makes the final percentage meaningless.

Each paper is built from this unit’s 42 terms and is the same for everyone, so a teacher can assign “Unit 4, Paper 3” and every student sits the identical test. Multiple choice is marked objectively; the written sections you mark yourself against the model answer and rubric.
Suggested time 37 min 34 points0/17 attempted
1

Terminal velocity of a falling loop

2

Applying Lenz's law to a falling magnet

3

Zero force parallel to the field

4

Negative charges: solve then flip

5

Domains and ferromagnetism

6

No magnetic monopoles

7

Magnetic field of a wire

8

Solenoid field

9

Charged particle in a magnetic field

10

Force on a current-carrying wire

11

Determining the field direction around a wire

12

The rod-on-rails chain

Short answer 1. Define or explain: The Fv against ε²/R check

3 pts

Short answer 2. Define or explain: Radius of circular motion

3 pts

Short answer 3. Define or explain: Why magnetic monopoles do not appear

3 pts

Short answer 4. Define or explain: Force on a moving charge

3 pts

Free response

10 pts

A straight wire segment of length L carries a current I to the right. The wire is placed in a uniform magnetic field of magnitude B directed into the page, perpendicular to the wire.

A(i). Indicate the direction of the magnetic force exerted on the wire. A(ii). Indicate the direction of the magnetic force that would be exerted on a positive charge moving to the right at the same location.

B. Derive an expression for the magnitude of the magnetic force exerted on the wire, in terms of B, I, L and physical constants.

C. A particle of mass m and charge +q enters the same field region moving perpendicular to the field with speed v. Derive an expression for the radius of its circular path.

D. A second particle with the same charge and speed but twice the mass enters the same region. Indicate whether its radius is greater than, less than, or equal to that of the first particle, and justify your answer using your expression from part C.