Refraction and Lenses
Practice Test
1.
Surface waves move in a position __________ to the direction of the wave motion.
a.
parallel
b.
both parallel and perpendicular
c.
in a circular motion relative
d.
perpendicular
Hint
2.
In Figure 16-4, if
r
is decreased to 0.25 m, what will be the total luminous flux striking the inside of the sphere?
a.
875 lm
b.
438 lm
c.
7000 lm
d.
1750 lm
Hint
3.
If in Figure 17-4 the image of the lamp is 5 ft behind the mirror and the girl is 1 ft in front of the mirror, where is the lamp?
a.
10 ft behind the girl
b.
4 ft behind the girl
c.
6 ft behind the girl
d.
5 ft behind the girl
Hint
4.
When an object is placed between the focal point and a concave mirror, the rays __________.
a.
converge and sight lines converge and form a real image
b.
diverge and sight lines converge and form a virtual image
c.
diverge and sight lines diverge and form a real image
d.
converge and sight lines diverge and form a virtual image
Hint
5.
In Figure 14-4, if you quadrupled the length of the string, what effect, if any, would it have on its period?
a.
The period would be doubled.
b.
The period would be quadrupled.
c.
The period would be halved.
d.
It would have no effect.
Hint
6.
In nearsightedness, the image is focused __________.
a.
beyond the retina
b.
directly on the retina
c.
in front of the retina
d.
in front of the eye
Hint
7.
Which type of mirror produces an image that is always erect, always the same height as the object, and always virtual?
a.
concave
b.
plane
c.
diffuse
d.
convex
Hint
8.
An image of a flower is seen through a lens. What is the object?
a.
a mirror
b.
a flower
c.
a lens
d.
an image
Hint
9.
__________ is the change in direction of a wave when it intersects a boundary between two different media.
a.
Diffusion
b.
Diffraction
c.
Refraction
d.
Reflection
Hint
10.
The incident angle that causes a refracted ray to lie along the boundary of a substance is the __________.
a.
critical angle
b.
refracted angle
c.
reflected angle
d.
normal angle
Hint
11.
A polarizer and analyzer will block all light if they are at __________ to each other.
a.
180° angles
b.
right angles
c.
parallel angles
d.
30° angles
Hint
12.
Farsightedness can be corrected with a __________.
a.
parabolic lens
b.
convex lens
c.
concave lens
d.
plane lens
Hint
13.
In Figure 14-4, if you doubled the mass of the pendulum, what effect, if any, would it have on its period?
a.
The new period would be the old period, divided by the square root of two.
b.
The new period would be the old period, times the square root of two.
c.
It would have no effect.
d.
The new period would be half the old period.
Hint
14.
Danish astronomer Ole Roemer first measured the speed of light by studying __________.
a.
the orbit of Io, a moon of Jupiter
b.
the Moon
c.
how lasers travel in space
d.
how light traveled around two mountains
Hint
15.
How does light normally travel?
a.
in a curved line
b.
in a straight line
c.
always toward a dark area
d.
in concentric circles
Hint
16.
When a wave pulse strikes a wall, it reflects back and is __________.
a.
amplified
b.
inverted
c.
changed from compressional to transverse
d.
reduced to zero
Hint
17.
Through which medium is the speed of light the fastest?
a.
air
b.
glass
c.
water
d.
vacuum
Hint
18.
The refractive indices of lenses are __________.
a.
independent of the refractive index of air
b.
less than air
c.
the same as air
d.
greater than air
Hint
19.
A single bump or disturbance that travels through a medium is a ___________.
a.
surface wave
b.
compressional wave
c.
continuous wave
d.
wave pulse
Hint
20.
How do the frequencies of red and violet light compare?
a.
They cancel each other out.
b.
Violet is higher.
c.
Violet is shorter.
d.
They are identical.
Hint
