Imaging Maintenance And Equipment

Front 1

• the study of stationary electric charges

• the study of the distribution of fixed charges

Back 1

electrostatics

Front 2

fundamental unit of electric charge

Back 2

(SI): coulomb (c)

Front 3

measured in volt (V)

Back 3

electric potential

Front 4

potential energy per unit charge

Back 4

volt (1 V = 1 J/C)

Front 5

measured in ampere (A)

Back 5

electric current (I)

Front 6

one coulomb of electric charge flowing per second

Back 6

ampere (1 A = 1 C/s)

Front 7

transfer or movement of electron from one object to another object

Back 7

electrification

Front 8

electrification is created by what

Back 8

• friction

• contact

• induction

Front 9

when one object is rubbed against another

Back 9

friction

Front 10

when two objects touch, permitting electrons to move from one to the other

Back 10

contact

Front 11

the process of electric fields acting on another without contact (most important method used in the operation of electronic devices)

Back 11

induction

Front 12

if one object has too few or too many electrons

Back 12

electrified

Front 13

the object that behaves as a reservoir for stray electric charges

Back 13

electric ground

Front 14

the lines of force that causes charged particles to move from one pole to another

Back 14

electric field

Front 15

points outward

Back 15

positive charge

Front 16

points toward

Back 16

negative charge

Front 17

unlike charges attract, like charges repel

Back 17

repulsion-attraction

Front 18

states that the electrical force between two charged objects is directly proportional to the product of the quantity of charge on the objects and inversely proportional to the square of the separation distance between the two objects.

Back 18

coulomb's law

Front 19

equation form of coulomb's law

Back 19

F = k•Q1•Q2 / d²

Front 20

do not have electric field

Back 20

uncharged particles

Front 21

charges uniformly distributed at the surface

Back 21

distribution

Front 22

the force between two charges.

• directly proportional to the product of their magnitudes

• inversely proportional to the square of distance between them

Back 22

inverse square law

Front 23

only negative charges move along the solid conductors

Back 23

movement

Front 24

what are tightly bound inside the nucleus?

Back 24

protons

Front 25

the study of electric charges in motion

Back 25

electrodynamics

Front 26

movement of electrons along the wire

Back 26

electric current

Front 27

what are the two types of current

Back 27

direct current and alternating current

Front 28

electrons that flow in only one direction

Back 28

direct current

Front 29

waveform of direct current

Back 29

straight line

Front 30

electrons that flow alternately in opposite direction

Back 30

alternating current

Front 31

waveform of alternating current

Back 31

sinusoidal

Front 32

what are the four magnetic states of matter

Back 32

conductor, insulator, semiconductor, superconductor

Front 33

any substance through which electrons flow easily.

example: copper, aluminum, water

Back 33

conductor

Front 34

variable resistance, obeys ohm's law, and requires voltage

Back 34

conductor

Front 35

any material that does not allow electron flow.

example: glass, rubber, clay

Back 35

insulator

Front 36

does not permit electron flow, extremely high resistance, and necessary with high voltage

Back 36

insulator

Front 37

a material that in some condition behaves as an insulator and as a conductor.

example: silicon, germanium

Back 37

semiconductor

Front 38

can be conductive, can be resistive, basis for computers

Back 38

semiconductor

Front 39

any material that allows electrons to flow without resistance.

example: niobium, titanium

Back 39

superconductor

Front 40

no resistance to electron flow, no electric potential required, must be very cold

Back 40

superconductor

Front 41

a pathway that permits electrons to move in a complete circle from their source through the various components and back again

Back 41

electric circuits

Front 42

take note

Back 42

more complex > the greater the resistance > decrease electric current

Front 43

the voltage across the total circuit or any portion of the circuit is equal to the current times the resistance

Back 43

ohm's law

Front 44

formula for ohm's law

Back 44

V = I • R (voltage)

R = V / I (resistance)

I = V / R (current)

Front 45

2 basic types of electric circuit

Back 45

series circuit and parallel circuit

Front 46

elements are connected at their ends rather than lying in a line along a conductor

Back 46

parallel circuit

Front 47

all circuit elements are connected in a line along the same conductor

Back 47

series circuit

Front 48

inhibits flow of electrons

Back 48

resistor

Front 49

provides electric potential

Back 49

battery

Front 50

momentarily stores electric charge

Back 50

capacitor

Front 51

increases or decreases voltage by fixed amount (AC only)

Back 51

transformer

Front 52

allows electrons to flow in only one direction

Back 52

diode

Front 53

• it is measured in watts (W)

• 1 W: 1 A (current) x 1 V (voltage)

Back 53

electric power

Front 54

formulas for electric power

Back 54

• P = IV

• P = I²R (for power losses)

Front 55

• fundamental property of forms of matter

• it has no smallest unit

Back 55

magnetism

Front 56

• any material that produce magnetic field

• has north and south pole

Back 56

magnets

Front 57

magnets thay have two poles

Back 57

• bipolar/dipolar

Front 58

two scientists that did an experiment about electromagnetic induction

Back 58

michael faraday and hans oersted

Front 59

• changing magnetic field induces current

• magnetic field generates electricity

• ammeter: measures current

Back 59

michael faraday's experiment

Front 60

measures current

Back 60

ammeter

Front 61

• moving or spinning charges induces magnetic field

• electricity generates magnetic field

Back 61

hans oersted experiment

Front 62

any charged particle in motion creates a magnetic field

Back 62

magnetism

Front 63

types of magnets

Back 63

• natural magnet (ex. lodestone)

• artificial permanent magnet (ex. compass)

• electromagnets

Front 64

four magnetic states of matter

Back 64

• nonmagnetic - unaffected

ex. wood & glass

• diamagnetic - weakly repelled

ex. water & plastic

• paramagnetic - weakly attracted

ex. gadolinium

• ferromagnetic - strongly magnetized

ex. iron, nickel & cobalt

Front 65

• like magnetic poles repel

• unlike magnetic poles attract

Back 65

magnetic laws

Front 66

• Imaginary lines ofmagnetic field enterthe south pole• Imaginary lines ofmagnetic field leavethe north pole

Back 66

magnetic laws

Front 67

• An electric current is induced in a circuit if some part of that circuit is in a changing magnetic field• Faraday and Oersted Experiment

Back 67

electromagnetic induction

Front 68

• He observed the currentin a changing magneticfield

• He described the first lawof electromagneticinduction

Back 68

michael faraday

Front 69

• He demonstrated thatelectricity can be used togenerate magnetic fields

Back 69

hans oersted

Front 70

The magnitude of the induced current depends on four factors:1. The strength of the magnetic field2. The velocity of the magnetic field as it moves pas the conductor3. The angle of the conductor to themagnetic field4. The number of turns in the conductor

Back 70

faraday's law

Front 71

mechanical motion produces electric current

Back 71

electric generator

Front 72

• it changes the intensity of alternating voltage and current

• applicable only on AC

Back 72

transformer

Front 73

• turns ratio greater than 1

• Ns > Np

• Vs > Vp

• Is < Ip

Back 73

step up transformer

Front 74

• voltage and number of turns are directly proportional

• formula: Vs/Vp = Ns/Np

Back 74

transformer law

Front 75

• current is inversely related to the number of turns and voltage

• formulas:

Is/Ip = Np/Ns

Is/Ip = Vp/Vs

Back 75

transformer law on current