2014/5/12
Week 7
We’ll start at 7:00
PHYS 1C PROBLEM SESSION COURSE INSTRUCTOR: DR. FRANK WUERTHWEIN
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Quiz Preparation Guidelines: 1. 2. 3. 4. 5.
Do the practice quiz questions Do the assigned homework Bring your own calculator Organize your own cheat sheet Remember your exam number
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Quiz Reminders: 1. The cheat sheet should be letter-sized and used only on one side. 2. You’re not allowed to use someone else’s calculator or cheat sheet during the quiz. 3. Only your Scantron will be collected when you are finished. 3
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Send Your Feedback Online
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Part I
Practice Questions
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A) 6
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Part I
Practice Questions
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A) 7
Spherical Mirrors •
Focal Point / Center of Curvature
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Ray Diagrams •
Parallel to the principal axis reflected to the focus
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Through the focus reflected parallel to the principal axis
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Through the center of curvature reflected back on
Spherical Mirrors Mirror Equation Thin Lenses Thin Lens Equation Practice Problems
itself 8
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Spherical Mirrors •
Concave Mirrors •
P < F : Upright , enlarged , virtual
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P = F : Impossible to see the image (infinitely faraway)
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C < P < F : Inverted , enlarged size , real
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P = C : Inverted , same size , real
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P > C : Inverted , reduced size , real
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Spherical Mirrors Mirror Equation Thin Lenses Thin Lens Equation Practice Problems
Ray diagram is risky in the quiz!
(Why?)
Spherical Mirrors •
Convex Mirrors •
P < |F| : Upright , smaller , virtual
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P = |F| : Upright , smaller , virtual
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C < P < |F| : Upright , smaller , virtual
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P = C : Upright , smaller , virtual
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P > C : Upright , smaller , virtual
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Ray Diagram Qualitative
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Mirror Equation Quantitative
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Spherical Mirrors Mirror Equation Thin Lenses Thin Lens Equation Practice Problems
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Ch26
Question 2
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(i) a c (ii) e (iii) a c
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Ch26
Question 9
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(C)
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Mirror Equation •
Quantitative - When it comes to: •
Location (where is the image / what is the focal length)
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Magnification (the size / factor of the image)
1 1 1 + = 𝑝 𝑞 𝑓 •
Spherical Mirrors Mirror Equation Thin Lenses Thin Lens Equation Practice Problems
Signs really matter Put it on the cheat sheet
Carefully copy it onto your cheat sheet!
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Magnification •
Orientation •
Positive – Upright
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Negative – Inverted
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ℎ′ 𝑞 𝑀= =− ℎ 𝑝
Size of the image
ℎ′
= 𝑀ℎ
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M < 1 : The image is smaller
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M = 1 : The image’s size is the same as the object’s
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M > 1 : The image is bigger
Spherical Mirrors Mirror Equation Thin Lenses Thin Lens Equation Practice Problems
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Ch26
Question 6
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(d) 16
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Thin Lenses •
Lens-makers’ equation
1 1 1 = (𝑛 − 1)( − ) 𝑓 𝑅1 𝑅2 • •
R1 / R2 is positive when the center of curvature is in back of lens. R1 / R2 is negative when the center of curvature is in front of the lens.
Thin Lenses 1 1 1 = (𝑛 − 1)( − ) 𝑓 𝑅1 𝑅2
Spherical Mirrors Mirror Equation Thin Lenses Thin Lens Equation Practice Problems
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Spherical Mirrors Mirror Equation Thin Lenses Thin Lens Equation Practice Problems
• •
f > 0 Converging Lens f < 0 Diverging Lens
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Thin Lens – Ray Diagram •
Ray Drawing Rules •
Parallel to the principle axis
Spherical Mirrors Mirror Equation Thin Lenses
refracted and through the focal point on the back side
Thin Lens Equation •
Through the focal point on the front side refracted and parallel to the principle axis
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Through the center of the lens continues in a straight line (no turns)
Thin Lens – Ray Diagram •
Converging Lens •
P < f : Upright , bigger , virtual
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P = f : No image (infinitely faraway)
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f < P < 2f : Inverted , bigger , real
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P = 2f : Inverted , same size , real
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P > 2f : Inverted , smaller , real
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Practice Problems
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Spherical Mirrors Mirror Equation Thin Lenses Thin Lens Equation Practice Problems
Diverging Lens •
P anywhere : Upright , smaller , virtual 20
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Ch26
Question 4
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(i) e (ii) a c
Thin Lens Equation 1 1 1 + = 𝑝 𝑞 𝑓 •
As well as the magnification formula
𝑀= •
ℎ′ 𝑞 =− ℎ 𝑝
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Spherical Mirrors Mirror Equation Thin Lenses Thin Lens Equation Practice Problems
Again, signs really matter. 22
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Sign Convention for Thin Lens Equation
The table is different from that for mirrors!
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Ch26
Question 3
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(b)
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Ch26
Question 8
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1.05
Ch26
Question 11
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(C) 26
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Spherical Mirrors
Practice Questions Part 2
Mirror Equation Thin Lenses Thin Lens Equation Practice Problems
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Part 2
Practice Questions
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D) 28
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Part 2
Practice Questions
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B) 29
Part 2
Practice Questions
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B) 30
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Part 2
Practice Questions
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A) 31
Part 2
Practice Questions
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A) 32
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Part 2
Practice Questions
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A) 33
Good Luck!
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