Section 20.1
Electric Charge
Practice Test
1.
Materials that allow charges to move about easily are called __________.
a.
plastics
b.
insulators
c.
conductors
d.
facilitators
Hint
2.
The best explanation for why the phenomenon in Figure 20-1 occurs is ____.
a.
the same electrical charges on the ruler and paper bits are attracted to each other.
b.
the paper bits are gravitationally attracted to the ruler.
c.
the opposite electrical charges on the ruler and paper bits are attracted to each other.
d.
the paper bits are magnetically attracted to the ruler.
Hint
3.
Charges placed on a conductor ____________.
a.
gather in the center of the conductor
b.
vanish after a few moments
c.
spread out over the surface of the conductor
d.
stay where they are placed
Hint
4.
If a positively-charged glass rod is suspended so that it turns easily, and another positively-charged glass rod is brought close to it, the two rods will __________.
a.
not react
b.
attract each other
c.
repel each other
d.
fuse
Hint
5.
If the positive charge of an atom's nucleus exactly balances the negative charge of the surrounding electrons, the atom is __________.
a.
positively-charged
b.
neutral
c.
static
d.
electrified
Hint
6.
What are the two kinds of electrical charges?
a.
destructive and constructive
b.
positive and negative
c.
high and low
d.
static and dynamic
Hint
7.
If the charge of an atom's nucleus is +2 and the charge of the surrounding electrons is -2, the atom is __________.
a.
electrically neutral
b.
positively-charged
c.
unstable
d.
negatively-charged
Hint
8.
Materials through which electrical charges will not move easily are called __________.
a.
insulators
b.
ions
c.
grounders
d.
conductors
Hint
