Exam 3: Static Electricity

Electrostatic charges occur on _____.

The semiconductor material used as a coating on copy machine drums is _____.

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.

Copy machines operate on the principle of static electricity.

Current always flows from positive to negative.

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 _____.

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.

Most lightning discharges associated with a cloud occur between the cloud and the ground.

The static charge sometimes used during spray painting is an example of a(n) _____ static charge.

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.

The shock that results from walking across a carpet and touching a doorknob is an example of a(n) _____ static charge.

Lightning is the result of static charges built up in clouds that contain a large amount of moisture.

Power lines are often protected by lightning _______________ that exhibit a very high resistance at the normal voltage of the line.

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

Within a lightning bolt, current flows _____.

Static electricity refers to electrons that _____ moving.

Selenium is a(n) _____.

Lightning rods provide an easy path to ground for current.

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

Nuisance static charges are more likely to occur when the air is _______________.