Ch 4: The Xray Circuit

Question 1

define electrodynamics

Answer 1

electricity
electric charges in motion

Question 2

What is a circuit?

Answer 2

a series of moving charges with occasional object or device that affects the flow

Question 3

T/F A closed circuit is a complete path where the electricity will flow.

Answer 3

True

Question 4

What is an open circuit?

Answer 4

pathway of electron/electrical flow is broken
happens when you turn off a light switch (opens the circuit)

Question 5

Describe the electron flow in a Direct current

Answer 5

electrons flow in 1 direction
positive and negative end

Question 6

Why is a DC important in the xray tube

Answer 6

so electrons flow one direction from cathode to anode

Question 7

describe an alternating current

Answer 7

electrons flow rapidly back and forth, changing direction
created by specialized generators
this generator changed the charge (polarity) making electrons flow in different directions

Question 8

Electricity usually results from the movement of the….

Answer 8

electrons through the circuit

Question 9

Electric potential is measure in….

Answer 9

volts

Question 10

Electric potential is selected on the generator as…

Answer 10

kvp

Question 11

Electric current is measured in…

Answer 11

amperes

Question 12

electric current is selected on the generator as…

Answer 12

mA

Question 13

electric resistance is measured in…

Answer 13

Ohm’s

Question 14

Equation for Ohm’s Law

Answer 14

V = IR
v - voltage
I - current
R - resistence

Question 15

What are two types of Electric current?

Answer 15

Alternating current
direct current

Question 16

How are the two types of electric current different?

Answer 16

Alternating: electron flows in both directions, fluctuating voltage
Direct: electrons flow in one direction, stable voltage

Question 17

Differentiate between conductor and insulator

Answer 17

conductor - supports the travel of electricity
insulator - resist electrical flow

Question 18

Define electromagnetism

Answer 18

any flow of electrons are surrounded by magnetic field

Question 19

Define self-induction

Answer 19

fluctuating magnetic field cuts through the turns of the coil creating opposing voltage
(primary/secondary)

Question 20

Define mutual induction

Answer 20

electricity induced in a secondary coil by a moving magnetic field
(step up/step down transformers)

Question 21

What is a transformer?

Answer 21

devices that convert electrical current from one potential diff (voltage) to another

Question 22

Why are transformers important in xray?

Answer 22

they are able to increase/decrease the voltage from the electricity in the wall to the voltage needed for creating the xray being done

Question 23

Define autotransformer

Answer 23

serves as both primary and secondary coil
single core and wire coil around it
turns ratio depends on technique selection

Question 24

What kind of transformer(s) use mutual induction?

Answer 24

step up and step down transformers

Question 25

What kind of transformer(s) use self-induction?

Answer 25

autotransformer

Question 26

Define step-up transformer

Answer 26

more coils in the secondary side of the transformer increases voltage

Question 27

Define step-down transformer

Answer 27

more coils in the primary side of the transformer decreases voltage

Question 28

Differentiate between the three types of transformers used in xray circuit

Answer 28

Auto - self-induction, can act as a step up or step down transformer, ability to increase or decrease voltage Step Up - more coils on the secondary side, increases voltage Step Down - more coils on the primary side, decreases voltage

Question 29

What are the three sections of the xray circuit?

Answer 29

primary (low voltage) side secondary (high voltage) side filament circuit

Question 30

What are the three main components of the x-ray circuit and what is involved in each?

Answer 30

High voltage power supply - transformers control unit to manipulate the power - generator X-ray tube - creating the x-rays

Question 31

Define rectification

Answer 31

converting AC to DC xray circuit is a full wave rectification circuit using 4 rectifiers

Question 32

Within an electrical circuit, the term "current" refers to the movement of what?

Answer 32

electrons

Question 33

In an electrical circuit, the term "voltage" refers to what?

Answer 33

electrical force that moves the electrons through the circuit

Question 34

Commercial power supplying the xray circuit is _____ (direct, alternating) current

Answer 34

alternating

Question 35

What is the primary difference between an AC and DC within an electrical circuit?

Answer 35

direction of electron flow

Question 36

What component of the xray circuit needs to use alternating current in order to function?

Answer 36

transformers

Question 37

Why must an xray tube be supplied direct current?

Answer 37

The electrons need to flow in one direction to prevent damage to the tube - cannot have electrons flowing back into the cathode Electrons move from cathode to anode ONLY

Question 38

T/F Direct current changes polarity but keeps a constant, stable voltage.

Answer 38

False DC does not change polarity (direction/charge)

Question 39

The difference in electrical charge between two points in a circuit is called the...

Answer 39

voltage

Question 40

What is the function of the rectifier within the xray circuit?

Answer 40

convert AC to DC

Question 41

The rectifier is located where in the xray circuit?

Answer 41

step-up transformer and the xray tube

Question 42

T/F Alternating current alternates between negative and positive polarity

Answer 42

True change in polarity causes the electrons to rapidly change directions

Question 43

What is half-wave rectification?

Answer 43

the negative portion of the pulse is removed, leaving large gaps between positive voltage peaks where xrays cannot be made

Question 44

what type of rectifier is used in modern day xray equipment?

Answer 44

Diode-based rectification

Question 45

What is a diode?

Answer 45

small electric device that allows alternating current to come in, but only direct current to go out

Question 46

What type of rectification occurs when negative voltage peaks are turned into positive voltage peaks

Answer 46

full-wave rectification

Question 47

a transformer operates on what principle?

Answer 47

electromagnetic induction

Question 48

How do step-up transformers affect amperage and voltage?

Answer 48

increase voltage, decrease amperage

Question 49

which type of transformer is incorporated within the high voltage portion of the xray circuit

Answer 49

step up transformer

Question 50

Define electromagnetic induction

Answer 50

magnetic field creates an electric current to flow

Question 51

How do you determine the turns ratio of a transformer?

Answer 51

ratio: number of secondary coils to number of primary coils

Question 52

A step down transformer has ___ (more/less) coils in the primary side than the secondary side

Answer 52

more

Question 53

If there are more coils in the secondary side of the transformer, what kind of transformer is it?

Answer 53

step up transformer

Question 54

What type of transformer is needed for the filament in the xray circuit in order for thermionic emission to be possible? Why?

Answer 54

step down transformer increases amperage to the level needed to heat up for thermionic emission