Chapter 3

A thundercloud cannot contain both positive and negative electric charges

False

Current always flows from positive to negative

False

An electroscope can be used to determine the polarity of an electrostatic charge

True

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 application of static electricity is used during the manufacture of sandpaper

True

The discharge of static electricity in thunderclouds creates lightning bolts

True

A precipitator is a type of

air filter

The lightning protection device that does not connect directly to the object to be protected is called the lightning ______________

arrestor

Insulators are the only materials that can hold ____________ stationary

electrons

The current flow that occurs within a lightning bolt flows

from negative to positive

If a thundercloud has a positive charge, the current in the lightning bolt will from from the

ground to cloud

Electrostatic charges occur on _____________

insulators

A static electric charge is an electric charge which ____________ moving

is not

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

If you walk across a carpet, touch the doorknob and get a shock, the shock was a result of a(n) ____________ static charge

nuisance

The static charge that accumulates on clothes in the 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

When an object protected by a lightning ____________ is struck by a lightning, it will bleed the lightning discharge to ground before the protected object can be harmed

rod

The semiconductor material used a a coating on copy machine drums is _______________

selenium

Selenium is a(n) ____________

semiconductor

The static charge sometimes used during spray painting is called a(n) _____________ static charge

useful