#1
A converging lens will be prescribed by the eye doctor to
correct which of the following?
a. glaucoma
c. farsightedness
b. nearsightedness
d. astigmatism
#2
You are designing contact lenses for someone whose near point
is 43 cm. What focal length lens should you prescribe so that an
object can be clearly seen when placed at 25 cm in front of the
eye?
a. 43 cm
c. 15 cm
b. 18 cm
d. 60 cm
#3
A lens is used as a magnifier. Which of the following statements
is incorrect?
a. The focal length of the lens must be negative.
b. The magnification is greatest when the eye focuses at
the near point.
c. The refractive power of the lens is positive.
d. The lens is convex.
#4
You are building a compound microscope with an objective lens
of focal length 1.1 cm and an eyepiece lens of focal length 5.0
cm. You mount the lenses 18 cm apart. What is the
approximate magnification of your microscope?
#5
The Yerkes refracting telescope has a 1-m diameter objective
lens of focal length 20 m and an eyepiece of focal length 2.0
cm. What is the magnification of the planet Mars as seen
through this telescope?
#6
Doubling the f-number of a camera lens will change the light
intensity admitted to the film by what factor?
a. 1/4
c. 1/2
b. 4
d. 2
#7
A camera lens is initially set at f/16 for a shutter speed of 1/30
s. If the amount of lighting on the subject is unchanged, and the
lens is set at f/5.6, what is the proper shutter speed at this
setting?
Answers
1: C
2: D
3: A
4: 80
5: 1000
6: A
7: 1/250 s