Delmars Unit 3
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
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
A ____ charge can either be positive or negative
static
_____ means not moving
static
Electrostatic charges occur on _____.
insulators
Selenium changes it's conductivity with a change of
light intensity
the charge that accumulates on an object is determined by the ___ used to produce the charge
materials
The semiconductor material used as a coating on copy machine drums is _____.
Selenium
a lighting bolt has an average voltage of about
15,000,000 volts
_____ electricity is caused by an imbalance of electrical charges (positive and negative)
Static
A precipitator is a type of _____.
air filter
A lightning protection device that is grounded at one end, with the other end close to but not touching the object to be protected, is called a lightning _____
arrestor
Power lines are often protected by lightning _______________ that exhibit a very high resistance at the normal voltage of the line.
arrestors
Power lines are protected by lightning ____
arrestors
two types of protection from lightning strikes are
arrestors and insulators
when selenium is in the prescience of heavy light, it has high ____
conductivity
Nuisance static charges are more likely to occur when the air is _____.
dry
Insulators are the only materials that can hold _____ stationary.
electrons
an object can be positively charged by ____ from it
removing electrons
Selenium is a(n) _____.
semiconductor
The discharge of ___ in thunderclouds creates lightning bolts
static electricity
Before a electroscope can be used, it must first be _____
charged
A instrument that can be used to determine the polarity of the electrostatic charge of an object is a ____
electroscope
Within a lightning bolt, current flows _____.
from negative to positive
_____ is a semiconductor material that changes its conductivity with a change of light intensity
Selenium
an object can be negatively charged by ___ to it
adding