SNC2D – Physics: Light and Geometric Optics

2011 Grade 10 Optics Culminating Review

c = 3.00 × 108 m/s
/
GRASS Method for Problem Solving
G – write down all Given values
R – write down what you are Required to find
A – Analyse the problem to determine what formula or concept should be used
S – calculate the Solution, using the correct units and rounding the answer appropriately
S – write a short Statement which answers the question

Match the source of light to its definition or example:

incandescent phosphorescence fluorescence chemiluminescence electric discharge light emitting diode

triboluminescence bioluminescence

______light produced by the absorption of radiation in one wavelength, followed by the re-radiation in another wavelength over a long time

______mint-flavoured lifesavers produce this kind of light when you crunch down on them with your teeth

______light produced by electric current passing through a semiconductor, highly energy efficient lighting

______angler fish, fireflies

______about 2% of the energy consumed goes towards producing light in these kinds of light bulbs

______light produced when electricity jumps over a large potential difference

______glow sticks, chemical reaction with no accompanying change in temperature

______tonic water under “black” light (ultraviolet radiation) produces this kind of glow


Refraction Questions

Table #1: The Index of Refraction of Various Media

Medium / Index of Refraction (n)
Air/vacuum / 1.00
Water / 1.33
Ethyl alcohol / 1.36
Quartz / 1.46
Vegetable oil / 1.47
Acrylic / 1.49
Glass / 1.52
Zircon / 1.92
Diamond / 2.42

1.  Does light bend towards the normal or away from the normal when it travels from glass to water? Explain.

2.  Why would a piece of quartz be closer to invisible when submerged in vegetable oil rather than in ethyl alcohol?

3.  Calculate the speed of light in glass, using the index of refraction for glass from Table #1. Use the GRASS method. (Answer: v = 1.97 × 108 m/s)


Ray Diagrams and Thin Lens Equation Problems

1.  For the following converging lens system, use the rules for drawing ray diagrams (Parallel Ray, Centre Ray and Focal Ray) to find the resulting image. Describe the image using SALT (Size, Altitude, Location, Type).

Description of Image:

S
A
L
T

2.  For the following converging lens system, draw a ray diagram to show that a virtual image is formed (i.e. the Parallel Ray and Centre Ray will converge on the same side as the object). Describe the image using SALT.

Description of Image:

S
A
L
T

3.  An object located 30 m away from a converging lens produces a focused image 15 cm away from the lens on the other side of the lens.

(a)  What is the magnification of this lens system? (Answer: -0.5)

(b)  What kind of image is produced? (Answer: real)

(c)  Is the image upright or inverted? (Answer: inverted)

(d)  What is the focal length of the lens? (Answer: 10 cm)

4.  A converging lens with a focal length of 20 cm has a 1.5 m tall object placed 80 cm away from the lens.

(a)  Where will the focused image be produced? (Answer: 26.7 cm away, on the other side of the lens)

(b)  What kind of image is produced, and what is its attitude? (Answer: real, inverted)

(c)  What is the magnification of this lens system? (Answer: -0.33)

(d)  How tall is the image? (Answer: 50 cm, or 0.5 m)