Module 2

Question 1

Who discovered xrays

Answer 1

Wilhelm Rontgen

Question 2

When were xrays discovered?

Answer 2

1896

Question 3

Where were xrays discovered

Answer 3

The Glasgow Royal Infirmary

Question 4

Who took the first Dental Xray

Answer 4

Otto

Walkhoff

Question 5

Radiography Definition

Answer 5

Uses x-rays to produce images of areas inside

objects

Question 6

Radiology

Answer 6

Uses images to diagnose and treat disease

Question 7

What is Electromagnetic radiation is made up from

Answer 7

both electric and magnetic fields

Question 8

What is a Photon

Answer 8

Waves are energy and momentum from one

point to another known as wave packet

Question 9

What is a photon is equivalent to

Answer 9

one quantum of

energy

Question 10

What mass does a photon have

Answer 10

None

Question 11

What happens to a photon is a frequency is doubled?

Answer 11

The photon is doubled

Question 12

How is energy of photons measured

Answer 12

In electron volts

Question 13

What is Frequency

Answer 13

Number of repetitions in a given time period

Question 14

With frequency what happens with more repetitions

Answer 14

More repetitions = higher frequency = shorter

wave length

Question 15

What is the estimated individual does from background radiation

Answer 15

2.7mSv per year

Question 16

ALARP

Answer 16

As Low As Reasonable Practicable

Question 17

List Xray Equipment in Dental Surgery

Answer 17

• Tube head
• Positioning arm
• Control panel
– Wall mounted
– Part of chair
– On wheels
– Hand held

Question 18

What is the outer casing of the tubehead

Answer 18

Lead - must be

checked regularly to ensure no cracks or damage

Question 19

What is the xray tube in and what is it filled with?

Answer 19

A glass envelope which is filled with oil to remove the heat

Question 20

Step up transformer voltage?

Answer 20

Increases 240V to 60 - 90kv

Question 21

Step down transformer voltage?

Answer 21

Decreases the 240v to

7-10v required to heat the filament

Question 22

Aluminum filtration

Answer 22

Removes harmful low energy

x-rays (soft x-rays less than 30kV)

Question 23

What is a cathode?

Answer 23

A tungsten filament centered in a

focusing cup

Question 24

How are Electrons are produced?

Answer 24

By the filament and are focused at the
target on the anode (the x-rays
are produced at the anode)

Question 25

In the Cathode the focusing cup has what charge and why?

Answer 25

The focusing cup has a negative charge – the same as the electrons – this helps direct the electrons to the target

Question 26

What does the focusing cup do?

Answer 26

Aims the stream of electrons to the focal spot on the target

Question 27

What happens when the exposure button is pressed?

Answer 27

the electricity flows from the filament in the cathode – the filament gets hot

Question 28

What do electrons do?

Answer 28

Electrons are released which surround the filament

Question 29

What happens when the filament gets hotter

Answer 29

The hotter the filament gets the greater number of electrons are released

Question 30

What is Anode comprised of?

Answer 30

Comprised of a tungsten target on a copper | base.

Question 31

What happens when electrons from filament hit the target?

Answer 31

When the electrons from the filament hit the target they generate the x-rays and heat. The copper base removes the heat so as it doesn’t get too hot

Question 32

High Voltage (kilovoltage, kV)

Answer 32

Connected between the anode and the cathode to accelerate the electrons from the negative filament to the positive target Kvp or Kilovoltage peak

Question 33

A Current (milliamperage, mA)

Answer 33

Flows from the cathode to the anode – Measurement of the quantity of electrons being accelerated

Question 34

Spacer Cone or Beam Indicating | Device (BID)

Answer 34

Direction the beam and sets the ideal distance from the focal spot on the target to the skin (FSD)

Question 35

What is the collimator

Answer 35

A metal disc with hole in the middle found by the window in the lead casing. It limits and shapes the beam and shapes to the same size as an intra oral film.

Question 36

maximum size of the collimator

Answer 36

40 x 50 mm

Question 37

Aluminum Filtration

Answer 37

moves non diagnostic low energy (soft) xrays which are easily absorbed by the patient and therefore is more damaging

Question 38

Where is Aluminum Filtration

Answer 38

Found between the collimator and the spacer | cone

Question 39

List components of Control Panel

Answer 39

* Mains switch * Timer * Exposure time selector * Film speed selector * Patient size selector * Mains voltage compensator * Kilovoltage selector * Milliamperage switch * Exposure adjustment for digital imaging

Question 40

What is Alternating Current

Answer 40

240V current is an alternating current- half is | negative and half is positive.

Question 41

What is the positive half of alternating current

Answer 41

The positive half only is needed for the production | of x-rays

Question 42

kV

Answer 42

Size of the tube voltage

Question 43

mA

Answer 43

Size of the tube current

Question 44

d

Answer 44

Distance from the target

Question 45

(t)

Answer 45

Time = length of exposure

Question 46

How do xrays travel and what is the law?

Answer 46

X-rays travel in straight lines and they obey the inverse square law – Intensity = I/d² - they decrease as you get further away from the beam

Question 47

What are xrays referred to as?

Answer 47

X-rays are referred to as ionising radiation

Question 48

How can Xrays affect film emulsion?

Answer 48

X-rays can affect film emulsion to produce a visual image and can cause certain salts to fluoresce