Unit 11 Test - Lenses

Refraction occurs

• at any unpredictable time.
• only at a wave front.
• when a wave changes speed and bends as it passes a boundary.

A beam of light travels fastest in (a)  

• air.
• water.
• glass.

A beam of light enters a medium where it travels slower. The beam is bent

• toward the normal.
• away from the normal.
• at 96 degrees upward

A person standing waist-deep in a swimming pool appears to have short legs because of light (a)  

• reflection
• refraction
• interference

Different colors of light travel at different speeds in a transparent medium causing light ___________.

• dispersion
• reflection
• interference

The fact that light reflects and refracts is evidence that it is a (a)  

• Neither
• particle
• wave

Total Internal Reflection occurs when

• the incident angle is less than the critical angle
• the incident angle is equal to the critical angle
• the incident angle is greater than the critical angle

Ray diagrams are used to

(a)  

• find the location of the image.
• find the focal point of a lens
• find the focal length

In drawing a ray diagram, rays can be drawn

• through the focal point in front of the lens
• through the center of the lens.
• both ways

All lenses rely on light rays (a)  

• travelling at a constant speed through the glass.
• changing speed and bending in the glass.
• travelling in straight lines through the glass.