Unit 3 and 4

within a lightning bolt,current flows_______.

from negative to positve

An _____ can be used to determine the polarity of a. electrostatic charge

electroscope

lodestone is a name for naturally occurring magnetic material that is also called_____.

magnetite

In a clothes dryer, the greatest static charges generally are built up on _______fabrics.

man made

The precitator uses a high voltage DC power supply to provide a set of wires with positive charges and a set of plates with_______ charge.

negative

Bringing a charge 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

To locate the north pole of an electromagnet, use the ________-hand rule.

right

When an object protects by lightning _______ is struck by a lightning bolt, it will bleed the lightning discharge to ground before the protected object cab be harmed.

rod

_______is the results of static charges built up in clouds that contain a large amount of moisture

Lightning

A lightning protection device that is ground at one end , with the other end close to but not touching the object to be protected is called a lightning ________.

arrestor

a basic law of magnetism states that unlike poles ______and like poles____.

attract,repel

What type of magnent depends o. flow current to produce a magnetic field.

electromagnet

Magnetism can be explained in terms of _____spin pattern

electron

If a thunder cloud has a positive charge the current in the lightning bolt will flow from the ______.

ground to the cloud

if a permanent magnent is cut into pieces, each piece _______ a separate magnent

is not

Man-made permanent magnent retain their magnetism_______than natural magnents.

longer

I. the English system , the total force producing a magnetic field is the_________.

magnentomotive force

The measure of a materials ability to be megnatized is called_______.

permeability

When a magnetic materials are all lined up, and increase in current flow no longer courses increase in magnetic field strength, the material has reached_______.

saturation

selenium is an______.

semiconductor

Earth contains magnetic_____.

poles

The measure of a materials resistance to magnetism is known as _______.

reluctance

The static charge sometimes used during spray painting is an example is a____static charge.

useful