Test

Question 1

A tungsten target can produce a continuous spectrum of x-ray photons when the X-ray tube is active. When considering the spectrum, define both x-ray beam intesnity (quantity) and the x-ray beam quality

Answer 1

Intensity= number of x-ray photons in the beam/ amount of energy passing through a unit area per unit of time

Quality= range of photon energies carried by x-ray beam. ‘Penetrating power’

Question 2

Explain how any of the following would/nt affect intesnity and quality of diagnostic x ray beam

1) size of tube current
2) distance of the detector from the target
3) exposure time
4) target material

Answer 2

1) tube current has affect on beam INTENSITY but no effect on QUALITY

2) The distance from anode target effects beam INTENSITY owing to INVERSE SQUARE LAW, no effect on quality as it doesn’t change x-ray output spectrum.

3) length of exposure affects INTENSITY as this is related to number of x-ray photons produced in a period. It has no effect on quality as it doesn’t influence max and effective photon energies produced

4)target material affects intensity by reducing it as production of breaking radiation os reduced
Quality is affected depending upon the content

Question 3

Q3) Derived quantities are produced from a combination of SI base units and always
contain one of the following three base units:

A) mol, K, s
(B) m, A, s
(C) mol, kg, s
(D) m, kg, s

Answer 3

(D) m, kg, s

Question 4

How many SI units

Answer 4

7

Question 5

SI unit for temp

Answer 5

Kelvin

Question 6

What is equal to 1mSv

Answer 6

10-3 Sv

Question 7

What multiplies is used to express a millionth

Answer 7

Micro

Question 8

What is equal to A= B/C, where B is at the start

Answer 8

B= C x A

Question 9

ATOMIC STRUCTURE
Q12) Which of the following statements about a proton is incorrect?
(A) It has a positive charge.
(B) It resides within the nucleus.
(C) It is always equal in number to the neutrons present.
(D) It is 1820 times the mass of an elect

Answer 9

C- it always equal in number to the neutrons present

Question 10

If an atom has 8 protons and 8 neutrons, its atomic number (Z) and atomic mass (A)
will be what?

Answer 10

Z- 8
A= 16

Question 11

What is the name of th band o electron orbitals that can jump up I’m to from the valence band via excitation

Answer 11

Conduction band

Question 12

What is a form of electromagnetic ionising radiation

Answer 12

Gamma decay

Question 13

What type of ionisation radiation are x-rays

Answer 13

Electromagnetic

Question 14

What is the rotating anode disc made of

Answer 14

Tungsten

Question 15

.
Q19) Which of the following is not a required characteristic of the filament in an X-Ray
machine?
(A) Low thermionic work function.
(B) Low vapour pressure.
(C) A strong metal.
(D) A melting point less than 1000 degrees Celsius.

Answer 15

D

Question 16

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Q20) A continuous X-Ray spectrum is produced by which of the following interactions?
(A) An electron interacting with the inner shell electrons of an atom in the target
material.
(B) An X-Ray photon being absorbed by an electron in an atom.
(C) An electron interacting with the nucleus of an atom in a target material.
(D) An X-Ray photon being scattered by an electron in an at atom

Answer 16

C

Question 17

Define attenuation

Answer 17

Reduction in the energy per unit area iof the x-ray beam

Question 18

Which of the following doesn’t lead to attenuation of an X-ray
Photoelectric absorption
Inelastic scatter
Filtration
Collimation

Answer 18

Collimation

Question 19

What is the half value sickness

Answer 19

The thickness of a substance that will transmit 50% of the x-ray photons to which it is exposed

Question 20

What does mAs indicate

Answer 20

Tube charge

Question 21

What does kV represent

Answer 21

Thousands of volts

Question 22

Q25) What does ‘0.25mm lead equivalent’ mean?
(A) A material has the same mass as 0.25mm of lead.
(B) A material is made of 0.25mm of lead.
(C) A material attenuates the x-ray beam as much as 0.25mm of lead.
(D) A material has the same density as 0.25mm lead

Answer 22

C

Question 23

24) In a Compton interaction, which of the following is true?
(A) The scattered photon can be diverted in any direction.
(B) The photon is totally absorbed.
(C) A characteristic x-ray and an electron are emitted.
(D) An alpha particle is spontaneously emitted by the photon.

Answer 23

A

Question 24

when can a person carry out exposure

Answer 24

in administration , the practitioner and employer are licensed to undertake the intended exposure

it has been justified by the practitioner as showing a sufficient net benefit

it has been authorised by the practitioner or the operator

reseacrh programme which has been approved

enquired pregnancy for childbearing potential

urgency of exposure

Question 25

what are the general duties of an employer

Answer 25

regularloy test equipment and its performance

Question 26

what is the operator and practioner responsible for

Answer 26

responsible for carrying out the radiation exposure.
Practitioners and Operators are responsible for justifying and authorising individual medical exposures based upon assessment information supplied by the Referrer

Question 27

what is the refferer resposnible for

Answer 27

a justifyable reasoning for refferel

Question 28

what is a milli

Answer 28

10 -3

Question 29

what is a micro

Answer 29

10 -6

Question 30

list types of ionising radiation

Answer 30

alpha particles, beta particles, positrons, gamma rays, and X-rays

Question 31

when are x-ray photons produced

Answer 31

when fast moving electrons (acceleratedby cathode) are suddenly stopped by the impact with the metal target (anode)

ke of electrons is converted to x-ray photons and into heat

Question 32

in a mass attenuation coefficents pb graph, what is on the x and y axis

Answer 32

bottom x= photon energy
y= mass attenuation coefficency

compton scatter dominates over a wide range of energies with all materials

Question 33

what is kVp

Answer 33

The kilovoltage peak (kVp) is the difference in potential applied to the X-ray tube