Refraction and Lenses
Practice Test
1.
What does the F on a ray diagram represent?
a.
the location of the object
b.
the focal point
c.
the location of the virtual image
d.
the center of the mirror
Hint
2.
In Figure 16-4, if
r
is decreased to 0.25 m, what will be the illuminance of the sphere?
a.
2224 lx
b.
139 lx
c.
8.69 lx
d.
556 lx
Hint
3.
To make red light white, add __________.
a.
yellow light
b.
magenta light
c.
green light
d.
cyan light
Hint
4.
The formula
represents the period of a pendulum, T. What is the period of a 3.5 m-long pendulum on Earth?
a.
3.2 s
b.
3.8 s
c.
1.4 s
d.
4.6 s
Hint
5.
If a wave's frequency increases, its period __________.
a.
increases
b.
remains the same
c.
decreases
d.
fluctuates
Hint
6.
The speed of a wave depends on the __________.
a.
medium
b.
frequency
c.
energy
d.
amplitude
Hint
7.
When an object is placed between the focal point and a concave mirror, the rays __________.
a.
converge and sight lines diverge and form a virtual image
b.
converge and sight lines converge and form a real image
c.
diverge and sight lines diverge and form a real image
d.
diverge and sight lines converge and form a virtual image
Hint
8.
Unlike mirrors, lenses have __________.
a.
many focal points
b.
no focal points
c.
one focal point
d.
two focal points
Hint
9.
The principle of superposition states that __________.
a.
waves from different mediums can combine to form a new wave
b.
waves can never combine
c.
the energy of a wave depends on its position
d.
two or more waves can combine to form a new wave
Hint
10.
A ray of light travels in a __________.
a.
straight line
b.
circle
c.
back-and-forth motion
d.
curved line
Hint
11.
In nearsightedness, the image is focused __________.
a.
in front of the retina
b.
directly on the retina
c.
in front of the eye
d.
beyond the retina
Hint
12.
For the situation shown in Figure 18-1b, which of the substances listed below should be chosen to put in front of the pencil to make its "break" the most pronounced?
a.
ethanol
b.
flint glass
c.
water
d.
vacuum
Hint
13.
A(n) __________ is a line perpendicular to a reflective surface.
a.
incidence
b.
angle
c.
normal
d.
reflection
Hint
14.
What is the speed of light in a diamond (
n
= 2.42)?
a.
2.42×10
8
m/s
b.
7.26×10
8
m/s
c.
1.24×10
8
m/s
d.
3.00×10
8
m/s
Hint
15.
In Figure 17-6, if the flame on the candle is 2 cm tall, how tall is the flame of the image?
a.
2 cm
b.
4 cm
c.
1 cm
d.
8 cm
Hint
16.
How does light normally travel?
a.
in a straight line
b.
in a curved line
c.
always toward a dark area
d.
in concentric circles
Hint
17.
A second prism will change a spectrum back into white light. This shows that __________.
a.
white light is composed of colors
b.
light travels at a constant speed
c.
prisms are transparent
d.
prisms distort images
Hint
18.
In Figure 14-1, if the spring's constant is 20.0 N/m and x has a value of 0.25 m, what is m equal to?
a.
5.0 kg
b.
0.63 kg
c.
0.51 kg
d.
0.06 kg
Hint
19.
__________ single lenses have chromatic aberration.
a.
Only concave
b.
All
c.
Only parabolic
d.
Only convex
Hint
20.
Farsightedness can be corrected with a __________.
a.
plane lens
b.
parabolic lens
c.
concave lens
d.
convex lens
Hint
