Answer to Question #51681 in Optics for samson

16 How far from a magnifying glass do you place an object to view it?
a. closer than than the focal length
b. distance equal to the focal length
c. greater than the focal length but less than twice the focal length
at twice the focal length
d.at twice the focal length
17 Telescopes that use mirrors as the objectives are known as -----------
a. refractors
b. reflectors
c. Galilean telescopes
d. terrestial telescopes
18 The property of light waves that detrmines its brightness is its -----------
a. wavelength
b. velocity
c. frequency
d. amplitude
19 The speed of light in glass is approximately ---------- that in air
a. 100 times faster than
b. 100 times slower than
c. 50 per cent faster than
d. 33 percent slower than