20150624

Physics final exam question: converging lens image same size as object

Physics 205B Final Exam, spring semester 2015
Cuesta College, San Luis Obispo, CA

Cf. Giambattista/Richardson/Richardson, Physics, 2/e, Problem 23.63

A Physics 205B student places a object 22 cm in front of (to the left of) a converging lens (f = +11 cm). Discuss why the size of resulting image will be exactly the same size as the original object. Explain your reasoning by using the properties of lenses, thin lens equations and/or ray tracings.

Solution and grading rubric:
  • p:
    Correct. Image will be the same size as the original object because:
    1. from the thin lens equation, the image distance q will be the same as the object image distance p;
    2. and from the linear magnification equation, the image height h' will be -hq/p, which makes the image the same size as (but inverted from) the original object.
  • r:
    As (p), but argument indirectly, weakly, or only by definition supports the statement to be proven, or has minor inconsistencies or loopholes. Typically shows that p = q, but does not explicitly relate this to how the image and object sizes compare.
  • 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.
  • x:
    Implementation/application of ideas, but credit given for effort rather than merit.
  • y:
    Irrelevant discussion/effectively blank.
  • z:
    Blank.
Grading distribution:
Sections 30882, 30883
Exam code: finalLd0c
p: 16 students
r: 18 students
t: 2 students
v: 2 students
x: 1 student
y: 1 student
z: 3 student

A sample "p" response (from student 5425):

A sample "r" response (from student 1675):

Physics final exam question: switching positions of ammeter and voltmeter

Physics 205B Final Exam, spring semester 2015
Cuesta College, San Luis Obispo, CA

Cf. Giambattista/Richardson/Richardson, Physics, 2/e, Problems 18.31, 18.41, 18.65

A 1.50 V emf battery with an unknown internal resistance r is connected to a light bulb of resistance R, and a voltmeter and an ammeter. All of these components are ideal. The internal resistance r is less than the resistance R of the light bulb. Discuss in which circuit (a) or (b) will the ammeter have a greater reading, or if there will be a tie. Explain your reasoning using the properties of voltmeters and ammeters, Kirchhoff's rules and Ohm's law.

Solution and grading rubric:
  • p:
    Correct. Understands that:
    1. a voltmeter has an infinite resistance, such that in circuit (a) it allows the current to flow through both the battery (with its internal resistance r) and the light bulb (of resistance R), while in circuit (b) the voltmeter prevents current from flowing through the light bulb, and only through the battery itself;
    2. from Ohm's law, the current flowing in circuit (a) is given by the emf of the battery divided by the sum of the resistances r and R, while in circuit (b) the current is given by the emf of the battery divided only the resistance r, such that the ammeter in (b) will have a higher reading than in the ammeter in (a).
  • r:
    As (p), but argument indirectly, weakly, or only by definition supports the statement to be proven, or has minor inconsistencies or loopholes. One of the two points (1)-(2) correct, other is problematic/incomplete.
  • t:
    Nearly correct, but argument has conceptual errors, or is incomplete. Only one of the two points (1)-(2) correct, other is missing, or both are problematic.
  • v:
    Limited relevant discussion of supporting evidence of at least some merit, but in an inconsistent or unclear manner.
  • x:
    Implementation/application of ideas, but credit given for effort rather than merit.
  • y:
    Irrelevant discussion/effectively blank.
  • z:
    Blank.
Grading distribution:
Sections 30882, 30883
Exam code: finalLd0c
p: 12 students
r: 5 students
t: 4 students
v: 12 students
x: 10 students
y: 2 students
z: 1 student

A sample "p" response (from student 5425):

A sample "v" response (from student 0621):

Physics final exam question: Cu-64 decay processes and daughter isotopes

Physics 205B Final Exam, spring semester 2015
Cuesta College, San Luis Obispo, CA

Cf. Giambattista/Richardson/Richardson, Physics, 2/e, Conceptual Question 29.4, Problem 29.26

Cu(64,29) can either undergo either β- decay or electron capture. Discuss whether these two processes will both result in the same daughter isotope, or instead will result in two different types of daughter isotopes. Explain your reasoning using properties of radioactive decay.

Solution and grading rubric:
  • p:
    Correct. Compares the two decay processes:
    1. β- decay emits an electron, in the process converting a neutron into a proton, which leaves the nucleon number the same, but increases the atomic number (resulting in zinc);
    2. electron capture takes in an electron to covert a proton into a neutron, which also leaves the nucleon number the same, but decreases the atomic number (resulting in nickel); thus two different types of daughter elements (different proton numbers) result from these two decay processes. (The daughter elements need not be explicitly named, as long as the different proton numbers are recognized.)
  • 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 garbled attempt at applying properties of radioactive decay.
  • x:
    Implementation/application of ideas, but credit given for effort rather than merit. Approach other than that of applying properties of radioactive decay.
  • y:
    Irrelevant discussion/effectively blank.
  • z:
    Blank.
Grading distribution:
Sections 30882, 30883
Exam code: finalLd0c
p: 16 students
r: 6 students
t: 5 students
v: 8 students
x: 2 students
y: 2 students
z: 4 students

A sample "p" response (from student 0104):

Physics final exam question: "resetting" solidification age of sample

Physics 205B Final Exam, spring semester 2015
Cuesta College, San Luis Obispo, CA

A rock sample with an extremely old solidification age (as determined by radioactive dating) is heated until it is molten, and then cooled back down to a solid. Discuss what happens to its solidification age (as determined by radioactive dating), and explain why this happens. Explain your reasoning using properties of radioactive decay.

Solution and grading rubric:
  • p:
    Correct. Discusses:
    1. the solidification age of a rock is determined by comparing the amount of gaseous decay products to the amount of unstable radioactive isotopes in the sample; a higher ratio of gaseous products to unstable isotopes corresponds to a sample that had solidified a long time ago; and
    2. heating the rock until molten would release the gaseous decay products, such that when it cools back down to a solid, it would have nothing to compare to the unstable isotopes that remain in the sample, effectively giving it a zero solidification age.
  • r:
    As (p), but argument indirectly, weakly, or only by definition supports the statement to be proven, or has minor inconsistencies or loopholes. One of the two points (1)-(2) correct, other is problematic/incomplete.
  • t:
    Nearly correct, but argument has conceptual errors, or is incomplete. Only one of the two points (1)-(2) correct, other is missing, or both are problematic.
  • v:
    Limited relevant discussion of supporting evidence of at least some merit, but in an inconsistent or unclear manner. Some garbled attempt at applying properties of radioactive decay.
  • x:
    Implementation/application of ideas, but credit given for effort rather than merit. Approach other than that of applying properties of radioactive decay.
  • y:
    Irrelevant discussion/effectively blank.
  • z:
    Blank.
Grading distribution:
Sections 30882, 30883
Exam code: finalLd0c
p: 11 students
r: 13 students
t: 6 students
v: 10 students
x: 0 students
y: 1 student
z: 2 students

A sample "p" response (from student 3019):

Another sample "p" response (from student 5080):

A sample "v" response (from student 1107):

Physics final exam problem: interference of two in-phase wi-fi antennae

Physics 205B Midterm 1, spring semester 2015
Cuesta College, San Luis Obispo, CA

Cf. Giambattista/Richardson/Richardson, Physics, 2/e, Problem 25.31

"Wifi"
Jason Cole
https://youtu.be/6hcK9B4HHY8

A commercially available wireless router[*] broadcasts at a 0.12 m wavelength from two vertical antennae spaced approximately 0.18 m apart. Assume that the two antennae are in phase. Determine how many destructive interference (minima) directions there will be (if any) in the 360° range of all possible directions. Show your work and explain your reasoning using the properties of source phases, path lengths, and interference.

[*] Linksys WRT54GL wireless router, 802.11b channel 1 (2412 MHz), overall width 200 mm, downloads.linksys.com/downloads/WRT54GL_V11_DS_NC-WEB,0.pdf

Solution and grading rubric:
  • p:
    Correct. Approximates two in-phase antennae as a double slit, and equates path length difference approximation dsinθ with destructive interference (minima) condition for in-phase sources to find θ = 19° and 90° as measured counterclockwise from the θ = 0° south direction, such that there are six unique directions of destructive interference in the 360° range of all possible directions. Okay if minima directions in the south-east quadrant are not correctly mapped via symmetry to find all minima directions, if at least the two unique θ = 19° and 90° directions in the southeast quadrant are found.
  • r:
    Nearly correct, but includes minor math errors. Only specifically searches over the cardinal directions, and finds of these that only east and west have destructive interference.
  • t:
    Nearly correct, but approach has conceptual errors, and/or major/compounded math errors.
  • v:
    Implementation of right ideas, but in an inconsistent, incomplete, or unorganized manner.
  • x:
    Implementation of ideas, but credit given for effort rather than merit. No clear attempt at applying path length differences and interference.
  • y:
    Irrelevant discussion/effectively blank.
  • z:
    Blank.
Grading distribution:
Sections 30882, 30883
Exam code: finalLd0c
p: 4 students
r: 13 students
t: 5 students
v: 11 students
x: 4 students
y: 3 students
z: 3 students

A sample "p" response (from student 5246):

A sample "r" response (from student 0104):

Physics final exam problem: finding unknown charge contributing to total electric field magnitude

Physics 205B Final Exam, spring semester 2015
Cuesta College, San Luis Obispo, CA

Cf. Giambattista/Richardson/Richardson, Physics, 2/e, Problem 16.15

Two point charges are held at fixed locations. An unknown charge is at the origin, and a –4.0 µC charge is at x = +0.20 m. The electric field at x = +0.10 m points to the right 
and has a magnitude of 1.8✕105 N/C. Determine 
the sign (±) and amount of the unknown charge (in either coulombs or µC) that is located at the origin. Show your work and explain your reasoning using properties of electric forces, fields, and vector superposition.

Solution and grading rubric:
  • p:
    Correct. Determines that:
    1. the electric field E1 at x = +0.10 m due to the Q1 = 4.0 μC charge at x = +0.20 m points to the right, but is more than the total electric field Etot at x = +0.10 m (that points to the right), thus the electric field E2 at x = +0.10 m due to the Q2 charge at the origin must point to the left, and so the charge Q2 must be negative as well;
    2. from setting up vector superposition of the two oppositely directed electric fields E1 and E2 at x = +0.10 m, that the Q2 charge at the origin must be -3.8 μC.
  • r:
    Nearly correct, but includes minor math errors.
  • t:
    Nearly correct, but approach has conceptual errors, and/or major/compounded math errors. At least recognizes that there is superposition of two electric fields at x = +0.10 m that result in the given Etot there.
  • v:
    Implementation of right ideas, but in an inconsistent, incomplete, or unorganized manner. Misinterprets Etot at x = +0.10 m m to be the electric force exerted by Q1 on Q2, and then solves for Q1 from Coulomb's law.
  • x:
    Implementation of ideas, but credit given for effort rather than merit. No clear attempt at applying electric forces, fields, and vector superposition.
  • y:
    Irrelevant discussion/effectively blank.
  • z:
    Blank.
Grading distribution:
Sections 30882, 30883
Exam code: finalLd0c
p: 3 students
r: 2 students
t: 8 students
v: 19 students
x: 4 student
y: 3 students
z: 4 student

A sample "p" response (from student 8282):

A sample "v" response (from student 9224):

20150611

Physics final exam problem: switched-in voltmeter

Physics 205B Final Exam, spring semester 2015
Cuesta College, San Luis Obispo, CA

Cf. Giambattista/Richardson/Richardson, Physics, 2/e, Problems 18.31, 18.72, 18.73

An ideal emf source is connected to two light bulbs (each with the same resistance R), a voltmeter, and an open switch. All of these components are ideal. Determine whether the voltmeter (magnitude) reading will increase, decrease, or remain constant when the switch is closed. Show your work and explain your reasoning using the properties of voltmeters, Kirchhoff's rules and Ohm's law.

Solution and grading rubric:
  • p:
    Correct. Understands that:
    1. when the switch is open, the voltmeter reading will be zero, as there is no potential difference between its terminals, and/or it is "not wired properly" and so will have a null/nonsense reading;
    2. when the switch is closed, no current will flow through the voltmeter (as it has infinite resistance), but it is wired in parallel to the left light bulb, and will read the light bulb's voltage drop ΔV = IR,
    thus closing the switch would result in a higher voltmeter reading.
  • r:
    Nearly correct, but includes minor math errors.
  • t:
    Nearly correct, but approach has conceptual errors, and/or major/compounded math errors.
  • v:
    Implementation of right ideas, but in an inconsistent, incomplete, or unorganized manner.
  • x:
    Implementation of ideas, but credit given for effort rather than merit. May confuse voltmeters with ammeters, and/or discusses how current will start to flow through voltmeter when switch is closed, etc.
  • y:
    Irrelevant discussion/effectively blank.
  • z:
    Blank.
Grading distribution:
Sections 30882, 30883
Exam code: finalLd0c
p: 10 students
r: 7 students
t: 4 students
v: 9 students
x: 9 students
y: 2 students
z: 2 students

A sample "p" response (from student 1288):

20150529

Education research: MPEX pre- and post-instruction results (Cuesta College, spring semester 2015)

The Maryland Physics Expectations survey (MPEX, Redish, Saul, and Steinberg, 1998) was administered to Cuesta College Physics 205B (college physics, algebra-based, mandatory adjunct laboratory) students at Cuesta College, San Luis Obispo, CA. The MPEX was given during the first week of the semester, and then on the last week of the semester, to quantify student attitudes, beliefs, and assumptions about physics using six question categories, rating responses as either favorable or unfavorable towards:
  1. Independence--beliefs about learning physics--whether it means receiving information or involves an active process of reconstructing one's own understanding;
  2. Coherence--beliefs about the structure of physics knowledge--as a collection of isolated pieces or as a single coherent system;
  3. Concepts--beliefs about the content of physics knowledge--as formulas or as concepts that underlie the formulas;
  4. Reality Link--beliefs about the connection between physics and reality--whether physics is unrelated to experiences outside the classroom or whether it is useful to think about them together;
  5. Math Link--beliefs about the role of mathematics in learning physics--whether the mathematical formalism is used as a way of representing information about physical phenomena or mathematics is just used to calculate numbers;
  6. Effort--beliefs about the kind of activities and work necessary to make sense out of physics--whether they expect to think carefully and evaluate what they are doing based on available materials and feedback or not.
Cuesta College
Physics 205B spring semester 2015 sections 30884, 30885
San Luis Obispo, CA campus
(N = 39, matched pairs, excluding negative informed consent form responses)

Percentage of (favorable:unfavorable) responses
Overall   Independence   Coherence   Concepts   Reality link   Math link   Effort   
Initial   57:2346:1748:3058:3071:1554:1965:19
Final   52:2738:2641:3454:2860:2051:2256:23

Previous posts:

Education research: SASS, ECCE and student learning outcomes assessment (Cuesta College, spring semester 2015)

Student achievement of course learning outcomes are assessed by administering an Student Assessment of Skills Survey (SASS), a five-point Likert scale questionnaire (Patrick M. Len, in development), and a shortened version (22 out of 45 questions) of the Electric Circuit Concept Evaluation (David Sokoloff, University of Oregon) to Physics 205B students at Cuesta College, San Luis Obispo, CA. This is the second semester of a two-semester introductory physics course (college physics, algebra-based, mandatory adjunct laboratory).

The SASS is administered online during the last week of instruction, to be completed before the final exam. The ECCE is administered in class during the last week of instruction.

The SASS results from this semester are compiled below. Values for the mean and standard deviations are given next to the modal response category for each question. Also listed is the percentage of students who have self-assessed themselves as having successfully achieving a learning outcome (responding "average," "above average," or "excellent") as opposed to not achieving success with a learning outcome (responding "very poor" or "below average").

Cuesta College
Student Assessment of Skills Survey (SASS)
Physics 205B spring semester 2015 sections 30882, 30883
N = 37

The questions below are designed to characterize your achievement of each of the learning outcomes by filling in a bubble on the rating scale provided to the right of each statement.

Mark the level of achievement that best describes your learning at the completion of the course.

1. Quantify the frequency, speed and wavelength of light.
(Achieved: 96%, unachieved: 4%)
Very poor.  [0]
Below average.  * [1]
Average.  **************** [16]
Above average.  ******* [7]
Excellent.  * [1]

2. Analyze the polarization of light.
(Achieved: 88%, unachieved: 12%)
Very poor.  [0]
Below average.  *** [3]
Average.  ********** [10]
Above average.  ********** [10]
Excellent.  ** [2]

3. Analyze reflection, refraction, and total internal reflection.
(Achieved: 92%, unachieved: 8%)
Very poor.  [0]
Below average.  ** [2]
Average.  ************* [13]
Above average.  ********* [9]
Excellent.  * [1]

4. Analyze images produced by lenses.
(Achieved: 96%, unachieved: 4%)
Very poor.  [0]
Below average.  * [1]
Average.  ************** [14]
Above average.  ********* [9]
Excellent.  * [1]

5. Understand optical systems such as cameras, eyes, simple magnifiers, microscopes and telescopes operate.
(Achieved: 88%, unachieved: 12%)
Very poor.  * [1]
Below average.  ** [2]
Average.  ************* [13]
Above average.  ******** [8]
Excellent.  * [1]

6. Analyze the constructive/destructive interference of waves.
(Achieved: 96%, unachieved: 4%)
Very poor.  [0]
Below average.  * [1]
Average.  ********* [9]
Above average.  ************ [12]
Excellent.  ** [2]

7. Understand how double-slits produce constructive/destructive interference.
(Achieved: 88%, unachieved: 12%)
Very poor.  [0]
Below average.  *** [3]
Average.  *************** [15]
Above average.  ****** [6]
Excellent.  * [1]

8. Analyze the diffraction produced by a single-slit.
(Achieved: 92%, unachieved: 8%)
Very poor.  [0]
Below average.  ** [2]
Average.  ******************* [19]
Above average.  *** [3]
Excellent.  * [1]

9. Understand how charges behave differently in conductors and insulators.
(Achieved: 64%, unachieved: 36%)
Very poor.  [0]
Below average.  ********* [9]
Average.  *********** [11]
Above average.  ***** [5]
Excellent.  [0]

10. Understand how a source charge exerts a force on a test charge (the direct model).
(Achieved: 83%, unachieved: 17%)
Very poor.  [0]
Below average.  **** [4]
Average.  ************ [12]
Above average.  ******* [7]
Excellent.  * [1]

11. Analyze the electric force exerted on a test charge by several source charges.
(Achieved: 84%, unachieved: 16%)
Very poor.  [0]
Below average.  **** [4]
Average.  *************** [15]
Above average.  ****** [6]
Excellent.  [0]

12. Understand how a source charge creates an electric field, which exerts a force on a test charge (the two-step field model).
(Achieved: 88%, unachieved: 12%)
Very poor.  [0]
Below average.  *** [3]
Average.  ************ [12]
Above average.  ********** [10]
Excellent.  [0]

13. Analyze the electric field created by several source charges.
(Achieved: 84%, unachieved: 16%)
Very poor.  [0]
Below average.  **** [4]
Average.  *********** [11]
Above average.  ********** [10]
Excellent.  [0]

14. Understand the relationship between electric potential and electric potential energy.
(Achieved: 92%, unachieved: 8%)
Very poor.  [0]
Below average.  ************ [2]
Average.  *********** [11]
Above average.  *********** [11]
Excellent.  * [1]

15. Analyze the characteristics of parallel plate capacitors.
(Achieved: 88%, unachieved: 12%)
Very poor.  [0]
Below average.  *** [3]
Average.  **** [4]
Above average.  *************** [15]
Excellent.  *** [3]

16. Quantify (using Ohm's law) the resistance, electric potential difference, and current of a circuit element.
(Achieved: 100%, unachieved: 0%)
Very poor.  [0]
Below average.  [0]
Average.  ********* [9]
Above average.  ************* [13]
Excellent.  ** [2]

17. Understand how to reduce configurations of resistors to an equivalent resistance.
(Achieved: 92%, unachieved: 8%)
Very poor.  [0]
Below average.  ** [2]
Average.  ************** [14]
Above average.  ****** [6]
Excellent.  *** [3]

18. Understand how to apply Kirchhoff's circuit rules (the junction rule and the loop rule).
(Achieved: 84%, unachieved: 16%)
Very poor.  [0]
Below average.  **** [4]
Average.  *********** [11]
Above average.  ******* [7]
Excellent.  *** [3]

19. Analyze the power used or supplied by circuit elements.
(Achieved: 84%, unachieved: 16%)
Very poor.  [0]
Below average.  **** [4]
Average.  ************** [14]
Above average.  **** [4]
Excellent.  *** [3]

20. Understand how a source magnet or current-carrying wire creates a magnetic field, which exerts a force on a moving charge or current-carrying wire (the two-step field model).
(Achieved: 92%, unachieved: 8%)
Very poor.  [0]
Below average.  ** [2]
Average.  ************* [13]
Above average.  ****** [6]
Excellent.  **** [4]

21. Analyze the direction of a magnetic fields and forces using the appropriate right-hand rules.
(Achieved: 100%, unachieved: 0%)
Very poor.  [0]
Below average.  [0]
Average.  *********** [11]
Above average.  ********* [9]
Excellent.  **** [4]

22. Understand how generators work.
(Achieved: 88%, unachieved: 13%)
Very poor.  [0]
Below average.  *** [3]
Average.  ******** [13]
Above average.  ******* [7]
Excellent.  * [1]

23. Understand how changing the magnetic flux through a wire loop produces an induced emf and an induced current (Faraday's law and Lenz's law).
(Achieved: 92%, unachieved: 8%)
Very poor.  [0]
Below average.  ** [2]
Average.  ************* [13]
Above average.  ********* [9]
Excellent.  * [1]

24. Analyze the step-up and step-down behavior of transformers.
(Achieved: 80%, unachieved: 20%)
Very poor.  [0]
Below average.  ***** [5]
Average.  ************** [14]
Above average.  *** [3]
Excellent.  *** [3]

25. Understand the conditions for stability and instability in atomic nuclei.
(Achieved: 75%, unachieved: 25%)
Very poor.  * [1]
Below average.  ***** [5]
Average.  *********** [11]
Above average.  ****** [6]
Excellent.  * [1]

26. Analyze various radioactive decay processes (alpha, beta-plus, beta-minus, electron capture, and gamma).
(Achieved: 83%, unachieved: 17%)
Very poor.  ** [2]
Below average.  ** [2]
Average.  *********** [11]
Above average.  ******* [7]
Excellent.  ** [2]

27. Analyze the time-dependent nature of radioactive decay activity.
(Achieved: 88%, unachieved: 12%)
Very poor.  ** [2]
Below average.  * [1]
Average.  **************** [16]
Above average.  ***** [5]
Excellent.  * [1]

28. Understand how Feynman diagrams are used to depict fundamental subatomic processes and interactions.
(Achieved: 68%, unachieved: 32%)
Very poor.  ** [2]
Below average.  ****** [6]
Average.  ************ [12]
Above average.  **** [4]
Excellent.  * [1]

Of the 28 student learning outcomes in the SASS, 18 were self-reported as being achieved by at least 85% of students, listed below in order of decreasing success:
16. Quantify (using Ohm's law) the resistance, electric potential difference, and current of a circuit element. (100%)
21. Analyze the direction of a magnetic fields and forces using the appropriate right-hand rules. (100%)
1. Quantify the frequency, speed and wavelength of light. (96%)
4. Analyze images produced by lenses. (96%)
6. Analyze the constructive/destructive interference of waves. (96%)
3. Analyze reflection, refraction, and total internal reflection. (92%)
8. Analyze the diffraction produced by a single-slit. (92%)
23. Understand how changing the magnetic flux through a wire loop produces an induced emf and an induced current (Faraday's law and Lenz's law). (92%)
14. Understand the relationship between electric potential and electric potential energy. (92%)
17. Understand how to reduce configurations of resistors to an equivalent resistance. (92%)
20. Understand how a source magnet or current-carrying wire creates a magnetic field, which exerts a force on a moving charge or current-carrying wire (the two-step field model). (92%)
2. Analyze the polarization of light. (88%)
5. Understand optical systems such as cameras, eyes, simple magnifiers, microscopes and telescopes operate. (88%)
7. Understand how double-slits produce constructive/destructive interference. (88%)
12. Understand how a source charge creates an electric field, which exerts a force on a test charge (the two-step field model). (88%)
15. Analyze the characteristics of parallel plate capacitors. (88%)
22. Understand how generators work. (88%)
27. Analyze the time-dependent nature of radioactive decay activity. (88%)

However, 10 student learning outcomes were self-reported as being achieved by less than 85% of students, listed below in order of decreasing success:
11. Analyze the electric force exerted on a test charge by several source charges. (84%)
13. Analyze the electric field created by several source charges. (84%)
18. Understand how to apply Kirchhoff's circuit rules (the junction rule and the loop rule). (84%)
19. Analyze the power used or supplied by circuit elements. (84%)
10. Understand how a source charge exerts a force on a test charge (the direct model). (83%)
26. Analyze various radioactive decay processes (alpha, beta-plus, beta-minus, electron capture, and gamma). (83%)
24. Analyze the step-up and step-down behavior of transformers. (80%)
25. Understand the conditions for stability and instability in atomic nuclei. (75%)
28. Understand how Feynman diagrams are used to depict fundamental subatomic processes and interactions. (68%)
9. Understand how charges behave differently in conductors and insulators. (64%)

Compare these student learning outcomes self-reported as not being achieved (9, 10, 11, 13, 18, 19, 24, 25, 26, 28) those from the previous semester (spring semester 2014: (5, 9, 11, 12, 14, 15, 22, 23, 24, 25, 26, 27, 28).

Student learning outcomes 16, 17, 18, and 19 for this semester were also directly assessed using a shortened version of Electric Circuit Concept Evaluation.

As per the ACCJC (Accrediting Commission for Community and Junior Colleges), results from this indirect assessment SASS tool, along with the direct assessment ECCE tool will be used for course/program improvement by increasing emphasis on these lowest three learning outcomes in instruction in future semesters.

Education research: ECCE statistics (spring semester 2015)

Students at Cuesta College (San Luis Obispo, CA) were administered a shortened version (22 out of 45 questions) of the Electric Circuit Concept Evaluation (David Sokoloff, University of Oregon) during the first and the last week of instruction. Physics 205B is the second semester of an algebra-based introductory general physics course covering optics, electromagnetism, and modern physics, with a mandatory adjunct laboratory component.

The pre- to post-test gain for this semester at Cuesta College (excluding students with negative informed consent forms (*.pdf), and missing pre- or post-tests) is:

Physics 205B spring semester 2015 sections 30882, 30883
N = 30
<initial%>= 31% ± 11%
<final%>= 40% ± 11%
<g>= 0.12 ± 0.19 (matched-pairs); 0.14 (class-wise)

This semester's ECCE post-instruction score is slightly lower than results from previous semesters at Cuesta College, and this semester's gain is lower than those in previous semesters.

Previous posts:
  • Education research: ECCE statistics (spring semester 2014).
  • Education research: ECCE statistics (spring semester 2012).
  • Education research: ECCE statistics (spring semester 2011).
  • Education research: ECCE statistics (fall semester 2010).
  •