Electrical Fundamentals

Question 1

Name three requirements for producing an induced voltage

Answer 1

1. Magnetic Field
2. Conductor
3. Relative motion between the two

Question 2

A Force moving through a distance is defined as:

Answer 2

Work

Question 3

The capacity to do work is defined as:

Answer 3

Energy

Question 4

Terms used to indicate the amount of something

Answer 4

Base units

Question 5

The symbol for work

Answer 5

W

Question 6

The symbol for energy

Answer 6

W

Question 7

The base unit for work

Answer 7

Joule (J)

Question 8

The base unit for energy

Answer 8

Joule (J)

Question 9

Force x Distance =

Answer 9

Work

Question 10

The base unit for force

Answer 10

newton (approximately 0.2248 pounds)

Question 11

The base unit for distance

Answer 11

meter (approximately 39.4 inches)

Question 12

1 newton-meter =

Answer 12

1 joule

Question 13

Formula for expressing efficiency (as a percentage)

Answer 13

useful energy out / useful energy in times (x) 100

Question 14

The smallest particle of a substance that still has all of its characteristics is called a:

Answer 14

molecule

Question 15

a molecule consists of

Answer 15

2 or more atoms

Question 16

matter composed of a single type of atom is called

Answer 16

an element

Question 17

when different kinds of atoms combine chemically they form

Answer 17

compounds

Question 18

The three major particles of an atom are

Answer 18

electron, proton and neutron

Question 19

The center of an atom is called a

Answer 19

nucleus

Question 20

The first shell of an atom can contain a maximum of _____ electrons

Answer 20

Two

Question 21

The second shell of an atom can contain a maximum of _____ electrons

Answer 21

Eight

Question 22

What is the maximum number of electrons that can occupy the third shell of an atom?

Answer 22

18

Question 23

What is the maximum number of electrons that can occupy the forth shell of an atom

Answer 23

32

Question 24

The electrons in the outermost shell of an atom are called

Answer 24

valence electrons

Question 25

Why are electrons capable of doing work?

Answer 25

All electrons possess energy. The possess energy because they have weight and they are moving

Question 26

Valence electrons that have been temporarily separated from an atom are called

Answer 26

free electrons

Question 27

A valence electron is freed from its atom when:

Answer 27

energy is added to the atom.

Question 28

An atom with a positive or negative charge is called

Answer 28

an ion

Question 29

The base unit of charge is a:

Answer 29

coulomb

Question 30

The symbol for charge is:

Answer 30

Q

Question 31

The abbreviation for coulomb is:

Answer 31

C

Question 32

The movement of charged particles in a specified direction is the definition for

Answer 32

Electric current

Question 33

The symbol for current is:

Answer 33

I | The symbol I was chosen because early scientists focused on the Intensity of electricity in a wire

Question 34

current that travels in the same direction all the time is called:

Answer 34

direct current (DC)

Question 35

The process of emitting electrons from a heated surface is called:

Answer 35

thermionic emission

Question 36

The base unit of current

Answer 36

ampere (coulombs per second)

Question 37

1 coulomb = (x) electrons

Answer 37

6.25 x 10 to the 18th power

Question 38

The electric pressure that causes current to flow

Answer 38

voltage

Question 39

The symbol for voltage

Answer 39

V

Question 40

energy in motion

Answer 40

kinetic energy

Question 41

energy at rest

Answer 41

potential energy

Question 42

the base unit of voltage

Answer 42

volt (joules per coulomb)

Question 43

List the 5 ways to produce voltage

Answer 43

``` Mechanical energy (generator) Chemical energy (battery) Heat energy (thermocouple) Pressure energy (piezoelectric crystal) Light energy (solarvoltaic cells) ```

Question 44

The opposition to current flow

Answer 44

resistance

Question 45

materials that offer little resistance to current flow

Answer 45

conductors

Question 46

materials that offer high resistance to current flow

Answer 46

insulators

Question 47

the sharing of valence electrons

Answer 47

covalent bonding

Question 48

materials that have no resistance to current flow

Answer 48

superconductors

Question 49

materials that are neither good conductors nor good insulators

Answer 49

semiconductors

Question 50

the base unit of resistance

Answer 50

ohm

Question 51

what 4 factors determine the resistance of an object?

Answer 51

1) Type of material 2) The length of the material 3) The cross sectional area of the material 4) The temperature of the material

Question 52

The change in resistance corresponding to a change in temperature is known as

Answer 52

temperature coefficient of resistance

Question 53

Give the formula for the relationship of resistance to length, cross-sectional area and resistivity of a material

Answer 53

Resistance (R) = resistivity (K) X length (L) / area (A) R = KL/A

Question 54

Materials with no free electrons are called:

Answer 54

insulators

Question 55

Semiconductors have ____ free electrons

Answer 55

four

Question 56

The characteristic resistance of a material is known as

Answer 56

resistivity

Question 57

The rate of doing work or using energy

Answer 57

power

Question 58

The base unit of power

Answer 58

watt or joule per second (J/s)

Question 59

Give the formula for the relationship between power, energy and time

Answer 59

Power (P) = energy (W) / time (t) P = W/t

Question 60

Give the formula for efficiency as it relates to power

Answer 60

% eff. = P-out / P-in X 100

Question 61

1 horsepower = ____ watts

Answer 61

746

Question 62

a drawing that uses only symbols to show how components are connected together is called a

Answer 62

schematic diagram

Question 63

A meter that measures only one quantity is called a:

Answer 63

panel meter

Question 64

cells that are not rechargeable are called

Answer 64

primary cells

Question 65

cells that are rechargeable are called

Answer 65

secondary cells

Question 66

the capacity of a cell or battery is expressed in

Answer 66

ampere-hours (Ah)

Question 67

a lead acid cell produces about _____ volts

Answer 67

2.1

Question 68

What is the chemical composition of the positive plate in a charged battery

Answer 68

lead peroxide (PbO2)

Question 69

What is the chemical composition of the negative plate in a charged lead acid battery

Answer 69

lead (Pb)

Question 70

What is the chemical composition of the electrolyte in a charged lead acid battery

Answer 70

dilute sulfuric acid (H2SO4)

Question 71

When a lead acid battery is overcharged water from the electrolyte is converted into:

Answer 71

hydrogen gas and oxygen gas

Question 72

The ratio of the weight of a substance to the weight of water is the definition for

Answer 72

specific gravity

Question 73

What is the specific gravity range for a fully charged lead acid cell?

Answer 73

1.21 to 1.28

Question 74

The typical automotive battery is fully charged at a specific gravity of

Answer 74

1.26

Question 75

A lead acid cell is considered discharged when the specific gravity drops below

Answer 75

1.12