NAO Volume 2 Questions with Complete
Solutions
Absorption - Correct Answer in terms of light and lens- when a ray of light enters a lens some of the
light will not completely travel through the lens
Deviation (Angle of) - Correct Answer the angle a ray of light is changed from its original path
Diffuse Relection - Correct Answer a reflection from a rough surface- the reflection does not produce
a clear image
Incidence (Angle of) - Correct Answer the angle which a ray of light makes the surface of a refracting
medium
Reflection - Correct Answer the return of light waves from a surface the production of an image
Refraction - Correct Answer the bending of light when going from one medium into another
Refraction (Angle of) - Correct Answer the angle created when a ray of light passes from one medium
into another
Specular Reflection - Correct Answer the forming of a clear image when light strikes a surface
Why is a red pencil red? - Correct Answer It reflects red rays back toward the eye and absorbs all the
other rays of visible light
Why is the blacktop black? - Correct Answer It does not reflect any rays back toward your eye; rather
it absorbs them all
If a light beam passes through a green sunglasses lens, why will the exciting light be green? - Correct
Answer The green rays are refracted through the lens and all other color rays are absorbed by the
pigments in the lens material
, When a ray of light travels from air into water (which is denser than air) what happens to the ray of
light if the ray is perpendicular to the surface? - Correct Answer If the ray is perpendicular to the
surface it slows down but does not change direction; it is not deviated or displaced
When a ray of light travels from air into water (which is denser than air) what happens to the ray of
light if the ray is not perpendicular to the surface? - Correct Answer If the ray is not perpendicular to
the surface it slows down and changes direction toward the normal; it is deviated from its original
path
When a ray of light travels from water into air ( which is rarer than water) what happens to the ray of
light if the ray is perpendicular to the surface? - Correct Answer If the ray is perpendicular to the
surface it speeds up but does not change direction; it is not deviated or displaced
hen a ray of light travels from water into air ( which is rarer than water) what happens to the ray of
light if the ray of light is not perpendicular to the surface? - Correct Answer If the ray is not
perpendicular to the surface it speeds up and changes direction away from the normal; it is deviated
from its original path
What does critical angle mean? - Correct Answer a light ray leaving a denser material is rarer material
that is at an angle of normal that results in it traveling parallel to the surface of the material. If the
angle of incidence is greater than the critical angle the ray will reflect inside the material and will not
exit into the rarer material
What are the three things that can happen to a ray of light when it passes through a lens? - Correct
Answer absorbed, reflected, refracted
What is the difference between a high index lens and a aspheric lens - Correct Answer high index
refers to the material of the lens; aspheric refers to the surface design of the lens
What is transposition? - Correct Answer is the changing of a precription from plus cylinder to minus
cylinder or the other way around
What type of image is formed by a minus lens? - Correct Answer virtual
A plus lens does what to a light ray that passes through it? - Correct Answer makes them converge
Solutions
Absorption - Correct Answer in terms of light and lens- when a ray of light enters a lens some of the
light will not completely travel through the lens
Deviation (Angle of) - Correct Answer the angle a ray of light is changed from its original path
Diffuse Relection - Correct Answer a reflection from a rough surface- the reflection does not produce
a clear image
Incidence (Angle of) - Correct Answer the angle which a ray of light makes the surface of a refracting
medium
Reflection - Correct Answer the return of light waves from a surface the production of an image
Refraction - Correct Answer the bending of light when going from one medium into another
Refraction (Angle of) - Correct Answer the angle created when a ray of light passes from one medium
into another
Specular Reflection - Correct Answer the forming of a clear image when light strikes a surface
Why is a red pencil red? - Correct Answer It reflects red rays back toward the eye and absorbs all the
other rays of visible light
Why is the blacktop black? - Correct Answer It does not reflect any rays back toward your eye; rather
it absorbs them all
If a light beam passes through a green sunglasses lens, why will the exciting light be green? - Correct
Answer The green rays are refracted through the lens and all other color rays are absorbed by the
pigments in the lens material
, When a ray of light travels from air into water (which is denser than air) what happens to the ray of
light if the ray is perpendicular to the surface? - Correct Answer If the ray is perpendicular to the
surface it slows down but does not change direction; it is not deviated or displaced
When a ray of light travels from air into water (which is denser than air) what happens to the ray of
light if the ray is not perpendicular to the surface? - Correct Answer If the ray is not perpendicular to
the surface it slows down and changes direction toward the normal; it is deviated from its original
path
When a ray of light travels from water into air ( which is rarer than water) what happens to the ray of
light if the ray is perpendicular to the surface? - Correct Answer If the ray is perpendicular to the
surface it speeds up but does not change direction; it is not deviated or displaced
hen a ray of light travels from water into air ( which is rarer than water) what happens to the ray of
light if the ray of light is not perpendicular to the surface? - Correct Answer If the ray is not
perpendicular to the surface it speeds up and changes direction away from the normal; it is deviated
from its original path
What does critical angle mean? - Correct Answer a light ray leaving a denser material is rarer material
that is at an angle of normal that results in it traveling parallel to the surface of the material. If the
angle of incidence is greater than the critical angle the ray will reflect inside the material and will not
exit into the rarer material
What are the three things that can happen to a ray of light when it passes through a lens? - Correct
Answer absorbed, reflected, refracted
What is the difference between a high index lens and a aspheric lens - Correct Answer high index
refers to the material of the lens; aspheric refers to the surface design of the lens
What is transposition? - Correct Answer is the changing of a precription from plus cylinder to minus
cylinder or the other way around
What type of image is formed by a minus lens? - Correct Answer virtual
A plus lens does what to a light ray that passes through it? - Correct Answer makes them converge
