Physics quiz archive: capacitors, circuits

Physics 205B Quiz 4, spring semester 2017
Cuesta College, San Luis Obispo, CA
Sections 30882, 30883, version 1
Exam code: quiz04Br7w



Sections 30882, 30883 results

0- 6 :
7-12 :	******* [low = 9]
13-18 :	******** [mean = 17.1 +/- 5.4]
19-24 :	******
25-30 :	** [high = 30]

Astronomy quiz archive: sun/spectra/star properties

Astronomy 210 Quiz 5, spring semester 2017
Cuesta College, San Luis Obispo, CA

Section 30674, version 1
Exam code: quiz05ne0W


Section 30674

0- 8.0 :	* [low = 8.0]
8.5-16.0 :	*
16.5-24.0 :	***
24.5-32.0 :	************ [mean = 26.8 +/- 7.5]
32.5-40.0 :	***** [high = 40.0]

Section 30676, version 1
Exam code: quiz05s4Ha


Section 30676

0- 8.0 :	* [low = 1.5]
8.5-16.0 :	****
16.5-24.0 :	**********
24.5-32.0 :	************** [mean = 26.5 +/- 7.9]
32.5-40.0 :	************ [high = 40.0]

Physics midterm problem: extending telescope length

Physics 205B Midterm 1, spring semester 2017
Cuesta College, San Luis Obispo, CA

Two converging lenses, with focal lengths of +40.0 cm (for the objective lens) and +2.5 cm (for the eyepiece) are used to make a telescope. The length of the telescope (measured from lens-to-lens) is adjusted by sliding cardboard tubes in or out. Starting with the telescope used to look at an object very far away (essentially at infinity), determine how much the length must be extended in order to look at a closer object 10 m away. Show your work and explain your reasoning by using ray tracings and/or thin lens equations, properties of lenses, images, and magnification.


[*] Alan M. MacRobert, "Astronomy with a $5 Telescope," Sky & Telescope, vol. 79 no. 4 (April 1990), p. 384.

Solution and grading rubric:

• p:
  The eyepiece must be moved back by approximately 2 cm because:
  1. the object at d_o1 = +∞ for the objective creates a real image at d_i1 = f₁ = +40.0 cm, which becomes the object at a distance d_o2 = f₂ = +2.5 cm for the eyepiece, thus the telescope length (lens-to-lens distance) is 40.0 cm + 2.5 cm = 42.5 cm;
  2. the object at d_o1 = +10 m for the objective creates a real image at a slightly farther distance of d_i1 = +41.7 cm, which becomes the object at the same distance d_o2 = f2 = +2.5 cm for the eyepiece, thus the telescope length (lens-to-lens distance) is now slightly longer: 41.7 cm + 2.5 cm = 44.2 cm;
  3. thus the slight increase (approximately 2 cm) in the objective image distance d_i1 requires the eyepiece to be moved back by the same amount in order for this image to be placed at its front focal point.
• 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 approach has conceptual errors, and/or major/compounded math errors. At least understands that the telescope length is f₁ + f₂ when focused at ∞, and some attempt at finding the telescope length d_i1 + f₂ when focused at a finite d_o1.
• v:
  Limited relevant discussion of supporting evidence of at least some merit, but in an inconsistent or unclear manner. Some garbled attempt at ray tracings and/or thin lens equations, the properties of lenses, images, and magnifications. May have used microscope magnification equation to find length between lenses.
• x:
  Implementation/application of ideas, but credit given for effort rather than merit. No clear attempt at applying ray tracings and/or thin lens equations, the properties of lenses, images, and magnifications.
• y:
  Irrelevant discussion/effectively blank.
• z:
  Blank.
  

Grading distribution:
Sections 30882, 30883
Exam code: midterm01AhC4
p: 5 students
r: 0 students
t: 7 students
v: 17 students
x: 1 student
y: 0 students
z: 0 students

A sample "p" response (from student 1412):

Astronomy quiz archive: solar system

Astronomy 210 Quiz 4, spring semester 2017
Cuesta College, San Luis Obispo, CA

Section 30674, version 1
Exam code: quiz04nqyL


Section 30674

0- 8.0 :
8.5-16.0 :	****** [low = 12.0]
16.5-24.0 :	****** [mean = 23.6 +/- 7.7]
24.5-32.0 :	*******
32.5-40.0 :	**** [high = 36.5]

Section 30676, version 1
Exam code: quiz04sl4M


Section 30676

0- 8.0 :	* [low = 7.0]
8.5-16.0 :	********
16.5-24.0 :	************** [mean = 22.9 +/- 7.8]
24.5-32.0 :	*********
32.5-40.0 :	******* [high = 36.5]

Astronomy midterm question: Sagittarius as both sun-sign and rising-sign?

Astronomy 210 Midterm 1, spring semester 2017
Cuesta College, San Luis Obispo, CA

An astronomy question on an online discussion board was asked and answered[*]:

NSt: I recently went to see an astrologer in my town, and was told that that my sun-sign is Libra and my rising sign is Aquarius. Anyways, is that wrong? If you want to figure it out, I was born 12/25 at 8:30 AM.
ArZ: It looks to me like you are clearly both a Sagittarius sun-sign with a Sagittarius rising sign.

Discuss why this answer is correct for an observer in San Luis Obispo, CA. Support your answer by clearly explaining how you used your starwheel to do this, along with any assumptions that you may have made. (Ignore daylight saving time. Assume you can see stars in daylight.)

[*] answers.yahoo.com/question/index?qid=20080921194418AAO10gc.

Solution and grading rubric:

• p:
  Correct. Discussion includes the following:
  1. confirms that Sagittarius is the sun-sign for a 12/25 birthday by finding that it is on the meridian at 12 PM on that day (where the sun also be located); and
  2. confirms that Sagittarius is the rising sign, as it is rising on the east horizon at 8:30 AM on 12/25.
• r:
  Nearly correct (explanation weak, unclear or only nearly complete); includes extraneous/tangential information; or has minor errors.
• t:
  Contains right ideas, but discussion is unclear/incomplete or contains major errors. Only has correct verification of sun-sign or rising-sun only.
• v:
  Limited relevant discussion of supporting evidence of at least some merit, but in an inconsistent or unclear manner. At least attempts to use starwheel in a systematic manner.
• x:
  Implementation/application of ideas, but credit given for effort rather than merit. Discussion not clearly based on using a starwheel in a systematic manner.
• y:
  Irrelevant discussion/effectively blank.
• z:
  Blank.

Grading distribution:
Section 30674
Exam code: midterm01nghT
p: 16 students
r: 0 students
t: 6 students
v: 1 student
x: 0 students
y: 0 students
z: 0 students

Section 30676
Exam code: midterm01sP4m
p: 35 students
r: 4 students
t: 5 students
v: 0 students
x: 0 students
y: 0 students
z: 0 students

A sample "p" response (from student 1988): Another sample "p" response (from student 9449):

Astronomy midterm question: seeing the third quarter moon in the dark sky?

Astronomy 210 Midterm 1, spring semester 2017
Cuesta College, San Luis Obispo, CA

An astronomy question on an online discussion board was asked and answered[*]:

Pdg: Is it possible to see the third quarter moon when the sky is dark at night?
CON: Yes, it is very possible, you just have to be awake and up after midnight and the sky has to be clear, or reasonably clear. Don't wait until dawn.

Discuss why this answer is correct for an observer in San Luis Obispo, CA. Support your answer using a diagram showing the positions of the sun, moon, Earth, and an observer on Earth.

[*] answers.yahoo.com/question/index?qid=20170107045840AA6CMVF.

Solution and grading rubric:

• p:
  Correct. Complete diagram and reasoning includes the following explanations:
  1. the third quarter moon, which is highest overhead at 6 AM, rises six hours earlier at 12 AM, and sets six hours after being highest overhead at 12 PM;
  2. the sun is up from 6 AM to 6 PM;
  3. so the third quarter moon can be visible in a dark sky from 12 AM to (just before) 6 AM.
• r:
  Nearly correct (explanation weak, unclear or only nearly complete); includes extraneous/tangential information; or has minor errors. Diagram and/or explanation has minor errors.
• t:
  Contains right ideas, but discussion is unclear/incomplete or contains major errors. May have not discussed why it is important to not "wait until dawn."
• v:
  Limited relevant discussion of supporting evidence of at least some merit, but in an inconsistent or unclear manner. At least attempts to draw a moon phase diagram and apply rise/overhead/set times.
• x:
  Implementation/application of ideas, but credit given for effort rather than merit. Discussion not clearly based on a moon phase diagram.
• y:
  Irrelevant discussion/effectively blank.
• z:
  Blank.

Grading distribution:
Section 30674
Exam code: midterm01nghT
p: 15 students
r: 1 student
t: 2 students
v: 3 students
x: 2 students
y: 0 students
z: 0 students

Section 30676
Exam code: midterm01sP4m
p: 31 students
r: 1 students
t: 7 students
v: 4 student
x: 1 student
y: 0 students
z: 0 students

A sample "p" response (from student 1337):

Astronomy midterm question: Mars in the east and Venus in the west at sunset?

Astronomy 210 Midterm 1, spring semester 2017
Cuesta College, San Luis Obispo, CA

An astronomy question on an online discussion board was asked and answered[*]:

g12: How can I find Mars and Venus?
Chr: Right now [February 2012] Mars is low in the east at sunset, while at the same time that Venus is low in the west.

Discuss how this answer could be correct for an observer in San Luis Obispo, CA, and how you know this. Support your answer using a diagram showing the positions of the sun, Mars, Venus, Earth, and an observer on Earth.

[*] answers.yahoo.com/question/index?qid=20120205171726AAsMiO0.

Solution and grading rubric:

• p:
  Complete diagram and reasoning includes the following explanations for an observer on Earth at sunset (6 PM):
  1. Mars can be placed in an orbit around the sun outside of Earth's orbit such that it is visible low over the observer's east horizon; and
  2. Venus can be placed in an orbit around the sun inside of Earth's orbit such that it is visible low over the observer's west horizon.
• r:
  Nearly correct (explanation weak, unclear or only nearly complete); includes extraneous/tangential information; or has minor errors.
• t:
  Problems with either diagram or discussion. May have:
  1. Mars in an inner orbit and/or Venus in an outer orbit; or
  2. observer not placed at sunset and/or east/west horizons switched.
• v:
  Limited relevant discussion of supporting evidence of at least some merit, but in an inconsistent or unclear manner. Diagram and discussion problematic.
• x:
  Implementation/application of ideas, but credit given for effort rather than merit.
• y:
  Irrelevant discussion/effectively blank.
• z:
  Blank.

Grading distribution:
Section 30676
Exam code: midterm01sP4m
p: 25 students
r: 3 students
t: 14 students
v: 1 student
x: 1 student
y: 0 students
z: 0 students

A sample "p" response (from student 0247):
Another sample "p" response (from student 2412):

Astronomy midterm question: Mars and Mercury both low in the west at sunrise?

Astronomy 210 Midterm 1, spring semester 2017
Cuesta College, San Luis Obispo, CA

An astronomy question on an online discussion board was asked and answered[*]:

Pdg: Can be Mars and Mercury be both low in the west at sunrise?
CON: No. Mars can be low in the west at sunrise, but Mercury cannot.

Discuss how this answer is correct, and how you know this. Support your answer using a diagram showing the positions of the sun, Mars, Mercury, Earth, and an observer on Earth.

[*] answers.yahoo.com/question/index?qid=20170106000722AAkerYG.

Solution and grading rubric:

• p:
  Complete diagram and reasoning includes the following explanations for an observer on Earth at sunrise (6 AM):
  1. Mars can be placed in an orbit around the sun outside of Earth's orbit such that it is visible low over the observer's west horizon; and
  2. Mercury can be placed in an orbit around the sun inside of Earth's orbit but will never be visible low over the observer's west horizon.
• r:
  Nearly correct (explanation weak, unclear or only nearly complete); includes extraneous/tangential information; or has minor errors.
• t:
  Problems with either diagram or discussion. May have:
  1. Mars in an inner orbit and/or Mercury in an outer orbit; or
  2. observer not placed at sunset and/or east/west horizons switched.
• v:
  Limited relevant discussion of supporting evidence of at least some merit, but in an inconsistent or unclear manner. Diagram and discussion problematic.
• x:
  Implementation/application of ideas, but credit given for effort rather than merit.
• y:
  Irrelevant discussion/effectively blank.
• z:
  Blank.

Grading distribution:
Section 30674
Exam code: midterm01nghT
p: 14 students
r: 0 students
t: 6 students
v: 0 student
x: 2 students
y: 0 students
z: 1 student

A sample "p" response (from student 9433):

Physics quiz archive: interference, electrostatics

Physics 205B Quiz 3, spring semester 2017
Cuesta College, San Luis Obispo, CA
Sections 30882, 30883, version 1
Exam code: quiz03d3St



Sections 30882, 30883 results

0- 6 :
7-12 :	* [low = 9]
13-18 :	*****************
19-24 :	******** [mean = 18.6 +/- 4.4]
25-30 :	** [high = 27]

Astronomy quiz archive: telescopes

Astronomy 210 Quiz 3, spring semester 2017
Cuesta College, San Luis Obispo, CA

Section 30674, version 1
Exam code: quiz03n5By


Section 30674

0- 8.0 :
8.5-16.0 :	*** [low = 15.5]
16.5-24.0 :	**********
24.5-32.0 :	***** [mean = 25.3 +/- 7.9]
32.5-40.0 :	***** [high = 40.0]

Section 30676
Exam code: quiz03s4adD


Section 30676

0- 8.0 :	* [low = 6.0]
8.5-16.0 :	*********
16.5-24.0 :	**************** [mean = 22.6 +/- 7.5]
24.5-32.0 :	*********
32.5-40.0 :	***** [high = 40.0]