Elect 3 of 5 study guide
Electrostatic charges occur on _____.
insulators
A static electric charge is an electric charge which _____ moving.
is not
An electroscope can be used to determine the polarity of an electrostatic charge.
True
The discharging of static electricity in thunderclouds creates lightning bolts.
True
If a thundercloud has a positive charge, the current in the lightning bolt will flow from the _____.
ground to the cloud
The precipitator uses a high-voltage DC power supply to provide a set of wires with a positive charge and a set of plates with a _____ charge.
negative
The semiconductor material used as a coating on copy machine drums is _____.
selenium
The static charge sometimes used during spray painting is called a(n) _____ static charge.
useful
The application of static electricity is used during the manufacture of sandpaper.
True
A precipitator is a type of _____.
air filter
If you walk across a carpet, touch a doorknob and get a shock, the shock was the result of a(n) _____ static charge.
nuisance
The static charge that accumulates on clothes in a dryer is a(n) _____ charge.
nuisance
Bringing a charged test object near the ball of a charged electroscope causes the leaves to move closer together. This indicates that the test object charge is the _____ polarity as the electroscope charge.
opposite
Insulators are the only materials that can hold _____ stationary.
electrons
The current flow that occurs within a lightning bolt flows _____.
from negative to positive
When an object protected by a lightning _____ is struck by a lightning bolt, it will bleed the lightning discharge to ground before the protected object can be harmed.
rod
Lightning is the result of static charges built up in clouds that contain a large amount of moisture.
True
Lightning rods provide an easy path to ground for current.
True
The lightning protection device that does not connect directly to the object to be protected is called the lightning _____.
arrestor
A thundercloud cannot contain both positive and negative electric charges.
False
Current always flows from positive to negative.
False
Selenium is a(n) _____.
semiconductor