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 1 / 2
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
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