Question 1

Current is measured by:

Accepted Answer

Amps.

Question 2

A volt is a measure of:

Accepted Answer

Energy per electron.

Question 3

Magnetism comes from:

Accepted Answer

Moving electric charge.

Question 4

In a permanent magnet, the magnetism comes from:

Accepted Answer

The spin of the electrons.

Question 5

Magnetic monopoles:

Accepted Answer

Have never been found.

Question 6

Rail guns push the projectile using:

Accepted Answer

Magnetic fields.

Question 7

Tesla wanted to use a transformer to distribute  electricity because:

Accepted Answer

It decreased the current going through long wires to reduce the loss of electricity.

Question 8

You can demagnetize a magnet by:

Accepted Answer

Heating it above the Curie point.

Question 9

Which of the following use or consist of permanent magnets:

Lodestones
Transformers
Compasses
Earphones

Accepted Answer

Lodestones, compasses, and transformers.

Question 10

Theoretically, the Earth should not have a permanent magnet in its core because:

Accepted Answer

Its interior is too hot.

Question 11

The Earth's magnetism comes from:

Accepted Answer

A dynamo in the core.

Question 12

The Earth flips its magnetism, on average, approximately

Accepted Answer

Twice every million years.

Question 13

The north geographic pole of the Earth:

Accepted Answer

Is a south magnetic pole.

Question 14

Compasses point north because:

Accepted Answer

There are electric currents in the iron core of the Earth.

Question 15

Electricity will heat a wire if it has:

Accepted Answer

a high current.

Question 16

Static electricity occurs when two surfaces rub  against each other and:

Accepted Answer

Electrons flow from one to another.

Question 17

Europe uses higher voltage in homes because it:

Accepted Answer

Creates less heat in home wiring.
Carries greater power?

Question 18

Lights and TVs in Europe tend to flicker because Europe uses:

Accepted Answer

220 volts, whereas the US uses 110 volts.

Question 19

When an object loses some electrons, it:

Accepted Answer

Has a positive charge.

Question 20

To get a spark, you normally need:

Accepted Answer

High voltage.

Question 21

A fuse is used in a house to prevent:

Accepted Answer

House wires from overheating.

Question 22

Th Earth's magnetic flips are used for:

Accepted Answer

Geologic dating.

Question 23

In a metal, electrons:

Accepted Answer

Can move freely.

Question 24

The aspect of electricity that would make it most dangerous is high:

Accepted Answer

Current.

Question 25

A certain kind of generator uses its own electricity to strengthen its own magnetic field. Such a generator is called a:

Accepted Answer

Dynamo

Question 26

The original superconductors were cooled with:

Accepted Answer

Liquid helium.

Question 27

Room-temperature superconductors:

Accepted Answer

Are used to carry electric power.

Question 28

High-temperature superconductors operate at approximately:

Accepted Answer

-123 C (Liquid nitrogen temperature)

Question 29

We use AC instead of DC because:

Accepted Answer

AC can use transformers.

Question 30

Topsy was executed with AC:

Accepted Answer

To show the dangers of high voltage.

Question 31

Edison wanted:

Accepted Answer

A power plant on every city block.

Question 32

The current through a flashlight bulb is:

Accepted Answer

About one amp.

Question 33

A stereo speaker produces sound by the force:

Accepted Answer

Of a magnetic field on an electric current.

Question 34

The light from an ordinary light bulb comes from the fact that:

Accepted Answer

The wire is heated by electricity.

Question 35

Tesla coil is a kind of:

Accepted Answer

Transformer.

Question 36

Submarines can be detected by their:

Accepted Answer

Magnetism.

Question 37

At the Curie temperature:

Accepted Answer

Magnetism disappears.

Question 38

Most electric power is generated by:

Accepted Answer

A wire moving through a magnetic field.

Question 39

What invention made it possible to change low voltage AC to high voltage AC?

Accepted Answer

Transformer.

Question 40

To reduce losses from resistance, electric power lines use:

Accepted Answer

Very high current.

Question 41

An example of a transformer is:

Accepted Answer

a Tesla coil.

Question 42

Better motors and earphones have recently been made possible by:

Accepted Answer

Stronger magnets.

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PHY1020-Chapter 6