Physics 2 · Unit 5 · Paper 1

Geometric Optics 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 1 Paper 2 Paper 3

Each paper is built from this unit’s 20 terms and is the same for everyone, so a teacher can assign “Unit 5, Paper 1” 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

Index of refraction

Magnification

Why a magnifying glass must be held close

Predicting image type without calculating

Real vs virtual images

Apparent depth

Fiber optics

Converging vs diverging lens

Chromatic aberration

Convex mirror

Sign conventions for lenses and mirrors

Real image on a screen

Short answer 1. Define or explain: Concave mirror

3 pts

Short answer 2. Define or explain: Law of reflection

3 pts

Short answer 3. Define or explain: Thin lens equation

3 pts

Short answer 4. Define or explain: Why the image of a half-covered lens is dimmer, not halved

3 pts

Free response

10 pts

A converging lens has a focal length of 12 cm. An object 4.0 cm tall is placed 18 cm from the lens on the principal axis. (a) Calculate the image distance and the image height, and state whether the image is real or virtual and upright or inverted. (b) Describe the principal rays you would draw to locate this image. (c) The object is now moved to 6.0 cm from the lens. Calculate the new image distance and magnification, and describe the image. (d) Explain, using your results, how a converging lens is used as a magnifying glass. (e) A student covers the lower half of the lens with tape. Predict the effect on the image formed in part (a) and justify your prediction.