Chapter 1

Question 1

Who discovered electricity nearly 2000 years ago and what did they notice that brought them to the conclusion?

Answer 1

The Greeks; they noticed that when a material that we now call amber was rubbed with some other materials, it became charged with a mysterious force. The charged amber attracted such materials as dried leaves and wood shavings.

Question 2

Ben Franklin believed there were 2 kinds of electricity. What were they?

Answer 2

Positive and Negative

Question 3

Today, scientists think electricity is produced by what?

Answer 3

Very tiny particles called Protons and Electrons

Question 4

A water molecule is made up of what?

Answer 4

2 Hydrogen atoms and 1 Oxygen atom

Question 5

What is Matter?

Answer 5

Anything that has weight and occupies space.

Question 6

What are Elements?

Answer 6

The basic materials that make up all matter.

Question 7

What is one molecule of Salt made of?

Answer 7

1 Sodium atom and 1 Chlorine atom

Question 8

What 3 subatomic particles make up an atom?

Answer 8

Protons, neutrons, and electrons

Question 9

Which particles are in the nucleus of an atom? Which are in the shells?

Answer 9

Protons and Neutrons are in the nucleus. Electrons orbit the nucleus in shells.

Question 10

The number of protons in the nucleus determines what?

Answer 10

How one atom of an element differs from another.

Question 11

How does a proton compare to an electron in size and weight?

Answer 11

Protons are one-third the diameter of an electron but have almost 1840 times the mass of an electron. Protons are smaller but much heavier.

Question 12

How many electrons does Copper have?

Answer 12

29. Atomic number of 29, meaning 29 protons, so same number of electrons.

Question 13

How do like and unlike charges interact? How do protons and electrons interact?

Answer 13

Like charges repel and opposite charges attract. Protons(+) repel other protons(+). Electrons(-) repel other electrons(-). And protons(+) attract electrons(-).

Question 14

What are charged atoms called?

Answer 14

Ions

Question 15

What makes an atom electrically neutral?

Answer 15

If it contains the same number of protons and electrons. The equal and opposite positive and negative charges cancel each other out, making it electrically neutral.

Question 16

Hydrogen atoms have how many shells?

Answer 16

1

Question 17

Atoms can have up to how many shells?

Answer 17

7

Question 18

What is the Valence Shell?

Answer 18

The outer shell of an atom. It will not have more than 8 electrons.

Question 19

What is the Electric Flow?

Answer 19

The flow of free electrons

Question 20

Atoms with only 1 valence electrons make the best what?

Answer 20

Conductors

Question 21

What are insulators?

Answer 21

Materials from which electrons are hard to free. Their valence shells are filled with 8 electrons or are more than half filled.

Question 22

What is a semiconductor?

Answer 22

Materials that are neither good conductors nor good insulators. They have half their valence shell filled, so 4 valence electrons.

Question 23

How many electrons can the second shell hold?

Answer 23

Up to 8

Question 24

Name 6 ways electricity is produced

Answer 24

Chemicals, Heat, Pressure, Friction, Magnetism, and Light. C.H.P, F.M.L.

Question 25

What is Piezoelectricity?

Answer 25

The name given to the effect of pressure in causing electrical charges.

Question 26

Light in itself is a form of energy, and is generally considered to be made of small particles of energy called what?

Answer 26

Photons

Question 27

How fast does electric current travel?

Answer 27

The speed of light, 186,000 miles per second

Question 28

For every electron that leaves the negative side of the battery, ___________________________?

Answer 28

an electron enters the positive side

Question 29

What happens when a good conducting wire is put directly across the terminals of a battery or generator?

Answer 29

A short circuit is produced

Question 30

Electron current flows from:

Answer 30

A low potential to a high potential, or between any difference of potential.

Question 31

What determines the electrical charge of an object?

Answer 31

The number of electrons that the object lost or gained

Question 32

Light can be produced by electricity without much heat, by such methods as:

Answer 32

Fluorescence, Phosphorescence, and Electroluminescence

Question 33

Any conductor that carries an electric current will act like what?

Answer 33

A magnet

Question 34

Where does a compass needle point?

Answer 34

North Magnetic pole

Question 35

How do the lines of flux flow in relation to the north and south poles?

Answer 35

Flux lines flow OUT of North Pole and INTO South Pole

Question 36

A solenoid is a helically wound coil that is made to produce a strong magnetic field. If the number of loops is increased and the loops are closely wound, what happens to the magnetic field?

Answer 36

It’s becomes even stronger.

Question 37

What is a Holding Relay?

Answer 37

A special relay that has an extra set of contacts to keep current flowing through the relay even after the main switch is released. Meaning another switch must be used to shut the relay off. IE start and stop buttons.

Question 38

How does the buzzer operate differently than a relay?

Answer 38

The contacts in the buzzer are specially arranged so that the electromagnetic coil cannot stay energized continuously.

Question 39

What does the commutator in a generator do in regards to the current?

Answer 39

It keeps it flowing in the same direction, DC. If the commutator was not used, it would produce AC.

Question 40

If a commutator was not used on a generator, what kind of current will it produce?

Answer 40

AC, alternating current