chapter 3 - Electricity

Question 1

Smallest unit of positive charge

Answer 1

Protons

Question 2

Smallest unit of negative charge

Answer 2

Electrons

Question 3

Free to move between orbitals and atoms

Answer 3

Electrons

Question 4

What concerns the distribution and movement of electrons and has little to do with the positively charged protons locked within the atomic nucleus

Answer 4

Electricity

Question 5

zero, neutral (so there wont be shock)

Answer 5

grounding

Question 6

Electric charges at rest

Answer 6

Electrostatics

Question 7

Repulsion

Answer 7

Attraction

Question 8

Do like charges repel or attract

Answer 8

repel

Question 9

Do unlike charges repel or attract

Answer 9

Attract

Question 10

Force between two charges directly proportional to product of their magnitudes and inversely proportional to square of distance between them

Answer 10

Inverse square law

Question 11

where is grounding located

Answer 11

secondary

Question 12

-Charges reside on external surface of solid conductors
-attempt to repel each other due to negative charges

Answer 12

Distribution

Question 13

where will the greatest concentration of chargers gather

Answer 13

they will gather at the sharpest area of curvature

Question 14

Charges move along surface of solid conductor

Answer 14

Movement

Question 15

What charges move along on solid conductor

Answer 15

Only negative

Question 16

Abrasion of two conductive materials creates a transfer of charges between the materials

Answer 16

Friction

Question 17

Physically touching a charged body to a neutral body, creates a transfer of charge

Answer 17

Contact

Question 18

Bring a charged body in close proximity to a neutral object, without physical contact, creates a charge in the neutral object

Answer 18

Induction

Question 19

how to electrons move

Answer 19

high to low concentration

Question 20

Occurs when one object is rubbed on another

Answer 20

Friction

Question 21

Occurs when two objects touch
Permits electrons to move from one object to another

Answer 21

contact

Question 22

Releases excess energy as light photons

Answer 22

static discharge

Question 23

Used in operation of electronic devices
Process of electric fields acting on one another without physical contact

Answer 23

Induction

Question 24

Electrodynamics consist of :

Answer 24

Movement of electrons(negative to positive)
Electric current
Properties of conducting materials
Electrical circuit
Electron sources

Question 25

what is the flow of electrons

Answer 25

negative to positive cathode to anode

Question 26

Conventional current flow

Answer 26

From positive to negative Due to movement of “electron holes” which is opposite to electron movement

Question 27

Quantity of electrons flowing

Answer 27

Current

Question 28

Force with which they travel

Answer 28

Potential difference (expressed as voltage)

Question 29

Direction of travel

Answer 29

Alternating current to Direct current (AC/DC)

Question 30

opposition to current flow

Answer 30

Impedance or resistance

Question 31

What is amperes

Answer 31

The current (how it is measured-unit)

Question 32

Quantity of electrons flowing amperes is the unit

Answer 32

Current

Question 33

-Force that drives electrons -Electromotive force (EMF) -voltage -area of higher to lower concentration of electrons

Answer 33

Potential Difference

Question 34

What current does the xray tube only operate on

Answer 34

xray tube can only operate on direct current

Question 35

what is needed to get direct current

Answer 35

Resistor

Question 36

what is the symbol for resistor

Answer 36

black triangle

Question 37

Resistance is dependent upon four things :

Answer 37

-materials conductivity -length -diamater -temperature

Question 38

-amount of opposition to current -measured in ohms - based upon current type -conductance (DC) - Admittance (AC)

Answer 38

Resistance

Question 39

Valence band and conduction band overlap

Answer 39

Conductors

Question 40

Valence band and conduction band in close proximity

Answer 40

Semi-conductors

Question 41

valence band and conduction band overlap greatly

Answer 41

superconductors

Question 42

valence band and conduction band far apart

Answer 42

Insulators

Question 43

materials conductivity is dependents on configuration of atoms:

Answer 43

-valence band -conduction band

Question 44

individual photon

Answer 44

kev

Question 45

kilovoltage peak

Answer 45

kvp

Question 46

what is the relationship between length and resistance

Answer 46

directly related

Question 47

why do electricians wire buildings using the shortest run possible ?

Answer 47

To lessen total resistance

Question 48

as length of solid conductor increase, what happens to resistance

Answer 48

increases proportionally

Question 49

what does the efficient circuit designs minimize ?

Answer 49

circuit pathways and length

Question 50

What is the relationship between diameter and resistance

Answer 50

inversely

Question 51

as cross sectional diameter of solid conductor increases, what happens to resistance

Answer 51

decreases

Question 52

what do thicker wires offer

Answer 52

less resistance

Question 53

how is the wire when the gauge number is lower

Answer 53

lower number, thicker wire

Question 54

what is the relationship between temperature and resistance

Answer 54

directly related

Question 55

what prevents electrons from flowing freely

Answer 55

increased atomic motion due to increased temperature

Question 56

what happens to resistance when there is an increase temp

Answer 56

decreased resistance (dont want it to heat up - Electronics engineers go to great lengths to minimize circuit heat build-up)

Question 57

Ohms Law

Answer 57

V=IR V= potential difference (volts) I=Current (amperes) R= resistance (ohms)

Question 58

Power

Answer 58

P=IV P=power (watts) I=current (amperes) V=potential difference (volts)

Question 59

A generator converts what energy ?

Answer 59

Mechanical to electrical

Question 60

Current flow is divided between branches of circuit

Answer 60

Parallel Circuits

Question 61

What happens to total resistance, amperage and total voltage as more resistance is added to parallel circuit

Answer 61

As more resistances are added to a parallel circuit, total resistance drops, total amperage increases, and total voltage remains unchanged.

Question 62

Rheostat

Answer 62

Variable resistor

Question 63

Devices to circuits for protection

Answer 63

-circuit breaker -fuse

Question 64

what happens to circuit temps when resistance is added in a parallel circuit

Answer 64

Increases circuit temps

Question 65

in what circuit do you add all the numbers together

Answer 65

series

Question 66

in what circuit do you take the lowest number and cut it in half

Answer 66

Parallel