Unit 6: Electromagnetic Induction
Physics C: E&M · Unit 6 · Paper 2

Electromagnetic Induction 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.

Paper 1Paper 2Paper 3
Each paper is built from this unit’s 21 terms and is the same for everyone, so a teacher can assign “Unit 6, Paper 2” 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

Faraday's law

2

Why Lenz's law must hold

3

Rotating loop generator

4

Three ways to change flux

5

Displacement current

6

Self-inductance and back EMF

7

Induced electric field

8

LC oscillation

9

Determining induced current direction

10

Magnetic flux

11

Motional emf

12

Force opposing motion

Short answer 1. Define or explain: Inductor behavior at t = 0 and t = ∞

3 pts

Short answer 2. Define or explain: Energy in an RL circuit

3 pts

Short answer 3. Define or explain: Inductance

3 pts

Short answer 4. Define or explain: Energy stored in an inductor

3 pts

Free response

10 pts

EXPERIMENTAL DESIGN AND ANALYSIS (Question 3, 10 points). In Experiment 1, students must determine the inductance L1 of an inductor using a linear graph. They have multiple charged capacitors of different known capacitances and a voltmeter that records potential difference as a function of time. In each trial the inductor is connected to a charged capacitor through an initially open switch (Figure 1), forming an LC circuit when closed. For C–D (Experiment 2): students determine the inductance L2 of a new inductor connected to a 12 V battery, a 10 Ω resistor, and an initially open switch (Figure 2). After the switch closes, the current I and its rate of change dI/dt are recorded. Table 1: dI/dt = 280, 230, 150, 100, 68 A/s at I = 0.40, 0.50, 0.75, 0.90, 1.00 A.

A(i). Indicate quantities the students could measure to determine L1 using a linear graph. A(ii). Briefly describe a method to reduce experimental uncertainty.

B(i). Indicate what to graph on each axis to create a linear graph usable to determine L1. B(ii). Briefly describe the relationship between L1 and a feature of that graph (an equation may be included).

C(i). Label the axes with measured or calculated quantities (with units) so the graph is linear and usable to determine L2. C(ii). Create the graph with numerical scales and plotted points. C(iii). Draw a best-fit line.

D. Using the best-fit line from part C(iii), calculate an experimental value for L2.