Copy of optics quiz.docx
SNC2D NAME: ____Tamima____ DATE: ____June 12, 2026____________
LIGHT & GEOMETRIC QUIZ
1. Match each electromagnetic wave from column A with the term from column B that is most closely related.
Column A Column B
a. X- rays Vitamin D [ f ]
b. ultraviolet light telecommunications [ c ]
c. radio waves cancer treatment [ a ]
d. infrared light radar [ e ]
e. microwaves theatre/concert effects [ g ]
f. gamma rays baggage screening [ b ]
g. visible light DVD player remote control [ d ]
2. Fill in the blanks with the correct term given below in the term bank:
Non-luminous, incandescence, converging lens, diverging lens , optical centre , principal focus, incident ray, image, reflection, perpendicular, reflected ray, reflection, incident light, light ray, opaque, geometric optics, transparent, translucent, luminous, electric discharge, phosphorescence, fluorescence, chemiluminescence, bioluminescence, triboluminescence , semiconductor, conductor, LED., Total internal reflection, mirror, angle of incidence, angle of refraction, normal, medium, visible light, electromagnetic spectrum, radiation, electromagnetic wave,
a. A line on a diagram representing the direction and path that light is travelling.
_____light ray_________
b. the use of light rays to determine how light behaves when it strikes objects.
_____geometric optics___________
c. the use of light rays to determine how light behaves when it strikes an object. ___________________
d. the light emitted from a source that strikes an object. _____Incident light_____________
e. when a material transmits all or almost all incident light; objects can be clearly seen through the material. _____transparent____________
f. When a material transmits some incident light but absorbs or reflects the rest; objects are not clearly seen through the material. _____translucent ________________
g. when a material does not transmit any incident light; all incident light is either absorbed or reflected; objects behind the material cannot be seen at all. ____opaque ________________
f. reproduction of an object through the use of light. _____image _______________
g. any polished surface reflecting an image, ____mirror_______________
h. the bouncing back of light from a surface. _____reflection________
i. the incoming ray that strikes a surface. ________incident ray__________
j. the ray that bounces off a reflective surface._______reflected ray___________
k. the angle between the incident ray and the normal. ___angle of incidence __________
l. the angle between the reflected ray and the normal. ____angle of refraction__________
m. the angle of incidence that results in an angle of refraction of 90 degrees.
___critical angle____________
n. the situation when the angle of incidence is greater than the critical angle?
____Total internal reflection ____________
o. a lens that is thickest in the middle and that causes incident parallel light rays to converge through a single point after refraction. __converging lens ________________
p. a lens that is thinnest in the middle and that causes incident parallel light rays to spread apart after refraction._____diverging lens ____________
q. point at the exact centre of the lens. ____optical centre _________________
r. the point on the principal axis of a lens where light rays parallel to the principal axis converge after refraction. ____principal focus _____________
s. light produced as a result of an electric current flowing only in one direction.
____LED. _________
t. material that allows current to flow in either direction. _______conductor _____________
u. the production of light from friction as a result of scratching, crushing, or rubbing certain crystals. _____triboluminescence ____________
v. the production of light in living organisms as the result of a chemical reaction with little or no heat produced. _____bioluminescence _______________
w. the process of producing light by the absorption of UV light resulting in the emission of the visible light over an extended period of time.______phosphorescence _____________
x. the immediate emission of visible light as a result of the absorption of UV light. _______fluorescence ___________
y. produces its own light. ____luminous ____________________
z. object that does not produce its own light. ____Non-luminous __________
z1. The production of light as a result of high temperature.
_____incandescence ___________________
z2. The process of producing light by passing an electric current through a gas.
____electric discharge ____________
z3. Any physical substance through which energy can be transferred. ___medium___________
z4. A method of energy transfer that does not require a medium; the energy travels at the speed of light. ___radiation ______________
z5. The electromagnetic waves that the human eye can detect.
_____visible light _______________
z6. The classification of electromagnetic waves by energy.
___electromagnetic spectrum __________________.
ANSWER THE FOLLOWING QUESTIONS OR SOLVE THE QUESTION.
3. a. Why are convex mirrors placed on sharp turns in a parking garage?
They bulge outward, which gives drivers a much wider view than a regular flat mirror. This helps people see around blind, sharp corners to avoid car crashes.
b. State other uses of convex mirrors.
Side mirrors on cars ("objects in mirror are closer than they appear"), security mirrors in store corners to spot shoplifters, and small mirrors on ATMs so you can see if anyone is behind you.
4. Describe the laws of reflection.
The incoming light ray, the bouncing light ray, and the normal line (the imaginary 90-degree line) all sit on the exact same flat surface.
The angle the light hits the mirror is exactly equal to the angle it bounces off. (Angle in = Angle out).
5. A concave mirror has a focus of 75 cm. an object is placed 60cm in front of the mirror. Describe the image characteristics of this object.
Because the object is placed at 60 cm, which is closer than the 75 cm focal point, the image will be:
- Larger (magnified)
- Right side up (upright)
- Behind the mirror
- Virtual (not a real image projected on a screen.
6. Do you think it is false advertising when a company claims that a laundry detergent cleans clothes better because the clothes become brighter when washed? Justify your answer?
Yes, it is kind of false advertising. The soap has special chemicals called optical brighteners that stick to the clothes. They absorb invisible UV light from the sun and glow with a blue light. This trick makes the clothes look brighter and whiter to our eyes, but it doesn't actually mean the clothes are any cleaner or that the dirt was removed better.
7. Which way will the light bend if it is travelling ? A. faster in a medium? B. slower in a medium.
A. Bends away from the normal line.
B. Bends toward the normal line.
8. Define index of refraction. Why is it a dimensionless quantity?
It is a number that shows how much light slows down when it enters a material compared to how fast it travels in space. It is a dimensionless quantity because you calculate it by dividing one speed by another speed. Since the units (m/s) are on both the top and the bottom, they cancel each other out completely, leaving just a plain number.
9. The speed of the light in vinegar is 2.30 x 108 m/s. determine the index of refraction for vinegar?
n = speed of light in space ÷ speed in vinegar
n = 3.00 × 10⁸ ÷ 2.30 × 10⁸
Answer: 1.30
10. Why do diamonds sparkle?
Diamonds have a really high index of refraction and a very small critical angle (about 24 degrees). Because the angle is so small, when light gets inside a properly cut diamond, it easily hits the inside edges at wide angles. Instead of escaping, the light bounces around inside like a pinball before shooting out the top into your eyes.
11. Explain how triangular prisms exhibit total internal reflections?
Glass has a critical angle of about 41 degrees. When light enters a triangular prism and hits the inside wall at a 45-degree angle, that angle is bigger than the critical angle. Because it is bigger, the light cannot escape through the glass and instead bounces back inside perfectly, acting exactly like a mirror.
12. The critical angle for sapphire is 34.4 degrees. For each angle of incidence, determine if it would result in total internal reflection in a sapphire.
a. 23.7 degrees - No (Too small, it just refracts out)
b. 34.7 degrees - Yes (Bigger than 34.4°)
c. 53.4 degrees - Yes (Bigger than 34.4°)
d. 31.5 degrees - No (Too small, it just refracts out)
13. What is the index of refraction for fluorite if light travels at a speed of 2.10 X 10 8 m/s in fluorite?
n = 3.00 × 10⁸ ÷ 2.10 × 10⁸
Answer: 1.43
14.A converging lens has a focal length of 16 cm. An insect is located 11 cm from the lens. Where will the image of the insect be located?