Test Flashcards
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
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’
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
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
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
(D) m, kg, s
How many SI units
7
SI unit for temp
Kelvin
What is equal to 1mSv
10-3 Sv
What multiplies is used to express a millionth
Micro
What is equal to A= B/C, where B is at the start
B= C x A
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
C- it always equal in number to the neutrons present
If an atom has 8 protons and 8 neutrons, its atomic number (Z) and atomic mass (A)
will be what?
Z- 8
A= 16
What is the name of th band o electron orbitals that can jump up I’m to from the valence band via excitation
Conduction band
What is a form of electromagnetic ionising radiation
Gamma decay
What type of ionisation radiation are x-rays
Electromagnetic
What is the rotating anode disc made of
Tungsten
.
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.
D