Exam 2: Phy 123 Study Guide
(These are guidelines only, you are expected to know all material covered in assignments,
lecture, readings, labs, and tutorials.
4. Reflection and Ray Optics
a. Understand how images and objects can be located by:
• Parallax
• Ray-Tracing
b. State the Law of Reflection and give examples to illustrate its meaning.
c. Use Ray-Tracing to show the following characteristics of an image in a curved mirror
(concave and convex):
• Image Location
• Image Type
• Image Size compared to the Object Size (Magnification)
• Image Orientation
5. Refraction and Ray Optics
a. State the Snell’s Law and give examples to illustrate its meaning.
b. Use the concept of refraction to predict the path (and speed) of light as it moves from
one substance to another.
c. Use Snell’s Law and the concept of Refraction to explain the function of a lens.
d. Apply Snell’s law to the explain the operation of such devices as:
• Optical Fiber
• Our eyes
• Glasses
• Prisms
• Cameras
• Telescopes
• Microscopes
6. Calculation related to image formation:
a. Understand the sign conventions with each of the following:
• Concave mirrors
• Convex mirrors
• Diverging lenses
• Converging lenses
b. Use the mirror equation or the thin-lens equation to calculate the following for single or
multiple optical devices:
• Object location
• Image location
• Focal length
• Magnification
Phys. 116: Outcomes
Eyres: wtr13
Review Mirrors and Lenses:
• The worksheet for lenses and curved mirror ray diagrams. You were asked for ray
diagrams, coordinate systems to find whether xi, xo, si, so were positive or negative.
• Equations relating to curved mirrors and lenses.
• The similar triangles that gave us the equations.
• Parallax
• Lab on Lenses
Review Snell’s Law:
• Lab on Snell’s Law
• You should be able to predict the direction of propagation when a wave travels from
one medium to another. Review the relationship of v, f, , n,  for these situations.
7. Light as a Wave
a. Use the concept of wave superposition to explain the fringe pattern resulting from:
• A Double-slit source
• Thin film interference
Review:
• Lab where we measured the wavelength of light.
Do You Understand Outcomes 4-7?
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You should be able to predict image location and characteristics from a verbal
description of the situation, from ray diagrams and from equations. You should also be
able to explain the coordinate system(s).
Can you describe in words or by drawing a picture what one would see when looking
into a mirror or through a lens for different situations and materials?
What would you predict when light (or other waves) pass from one medium to another.
Could you predict relationships (equations and graphs) between variables such as v, f, ,
n, Or between xi, x0, si, s0, f for lenses and mirrors?
You should be able to calculate wavelengths of light or any other particle given the
appropriate information. You should know what methods are available and what
measurements would be needed.
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Phys. 116: Outcomes
Eyres: wtr13