Electric Fields
Practice Test
1.
An electric field is about 150 N/C downward. What is the direction of the force on a positively-charged particle?
a.
changes rapidly
b.
stationary
c.
upward
d.
downward
Hint
2.
In Figure 21-7b, if both charges were 7.0
μ
C and the left charge were held in place while the right charge were moved from a separation of 0.4 m" to "0.40 m, how much work would be done on the system?
a.
2.2 J
b.
1.1 J
c.
-2.2 J
d.
-1.1 J
Hint
3.
__________ is the change in direction of a wave when it intersects a boundary between two different media.
a.
Diffraction
b.
Refraction
c.
Reflection
d.
Diffusion
Hint
4.
Objects that are lifted against the force of gravity have stored energy known as __________.
a.
potential energy
b.
kinetic energy
c.
reference levels
d.
resistance
Hint
5.
The formula
represents the period of a pendulum, T. What is the period of a 3.5 m-long pendulum on Earth?
a.
3.8 s
b.
3.2 s
c.
4.6 s
d.
1.4 s
Hint
6.
Amorphous solids have no __________.
a.
shape
b.
liquid phase
c.
volume
d.
crystalline pattern
Hint
7.
A large chunk of ice with mass 12.0 kg falls from a roof 6.00 m above the ground. Ignoring air resistance, what is the speed of the ice when it reaches the ground?
a.
12.1 m/s
b.
12.5 m/s
c.
7.67 m/s
d.
10.8 m/s
Hint
8.
If the charge of an atom's nucleus is +2 and the charge of the surrounding electrons is -2, the atom is __________.
a.
positively-charged
b.
unstable
c.
negatively-charged
d.
electrically neutral
Hint
9.
In the set-up of Figure 21-9, if a drop is moving down with a constant speed, then ___.
a.
the lower plate must be negatively charged
b.
the gravitational force on the drop must be greater than the electric force on the drop
c.
the upper plate must be negatively charged
d.
the gravitational force on the drop must be equal to the electric force on the drop
Hint
10.
The magnitude of the charge of an electron is called the __________.
a.
negative charge
b.
frequency
c.
elementary charge
d.
secondary charge
Hint
11.
According to Coulomb's law, the force on a test charge is __________ the test charge.
a.
equal to
b.
greater than
c.
proportional to
d.
less than
Hint
12.
Why is it important to take thermal expansion into account when building bridges?
a.
so the bridge materials can change state as the weather changes
b.
so the bridge materials don't deteriorate
c.
so the bridge materials expand and contract with the changes in weather
d.
so the bridge will not move at all
Hint
13.
A pulse traveling along a bullwhip is an example of a __________ wave.
a.
compressional
b.
longitudinal
c.
transverse
d.
surface
Hint
14.
Materials through which electrical charges will not move easily are called __________.
a.
grounders
b.
conductors
c.
insulators
d.
ions
Hint
15.
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.
0.51 kg
b.
5.0 kg
c.
0.63 kg
d.
0.06 kg
Hint
16.
Coulomb's law states that __________.
a.
the magnitude of the force between two charges is proportional to the magnitude of the charges and inversely proportional to the square of the distance between them
b.
the ratio of the potential difference to the current is constant
c.
the magnitude of the force between two charges is inversely proportional to the magnitude of the charges and proportional to the square of the distance between them
d.
the direction of the magnetic field in a wire is perpendicular to the flow of electric current in the wire
Hint
17.
What does a wave carry?
a.
heat
b.
matter
c.
particles
d.
energy
Hint
18.
Waves become inverted if they reflect off a medium that is __________ than the initial medium.
a.
less dense
b.
softer
c.
more gaseous
d.
more dense
Hint
19.
You lift a 2.73-kg textbook from the floor to a shelf 1.75 m above the floor. What is the book's gravitational potential energy relative to the floor?
a.
14.3 J
b.
93.1 J
c.
-46.8 J
d.
46.8 J
Hint
20.
A bike rider approaches a hill at a speed of 3.5 m/s. The mass of the bike and rider together is 77 kg. The rider coasts up the hill. Assuming that there is no friction, at what height will the bike come to rest?
a.
0.62 m
b.
3.7 m
c.
4.1 m
d.
1.6 m
Hint
