# Physics

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Scattered radiation can be describes as:
Noise which does not convey useful information for the patient
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If the focus of the x-ray tube is 1 mm, the focus is 100cm from the detector and the object is 1 cm from the detector calculate the unsharpness:
0.01 mm
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The grid ratio is:
The height of the lead ***** to the thickness of the interspace
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The voltage of an X-ray beam is conventionally measured in:
kVp
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If a radiographic image requires 20 mAs to produce the required density and the mAs was set at 200 mAs, what is the time setting?
0.01 seconds
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if the output of an x-ray tube is measured at 20 mGy at 100cm, what will the approximate output at 3m?
2.2 mGy
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The SI base of absorbed radiation dose is the:
Gray
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The SI unit of dose equivalent is the:
Sievert
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The SI unit of radioactivity is the:
Becquerel
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Ten to the power of 2 (10 2) is equivalent to:
100
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If we consider carbon written as follows: 12 C 6 which statement is true? The atoms have:
6 protons, 6 neutrons and 6 electrons
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Which statment bes describes electrons
Negative charge with an atomice weight of 1/1840 that of a proton
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Which statment best describes elements?
Elements are made of one type of atom
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Which statment best describes an isotpe?
Is an atom with less or more neutrons than protons.
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not influenced by external factors such as heat or pressure and does NOT involve electrons
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Radioactive emissions have different abillity to penetrate materials. Alpha particles are?
Relatively big and heavy in atomic terms and a highly ionising form of radiation but not able to penetrate skin
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Waves have three main components; amplitude, frequency and speed. The amplitude is:
Is the height of the wave
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Electrical charge is present if:
There are more protons than electrons resulting in a net positive charge overall
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Radiation that the wavelenght varies according to the frequency
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Classified by both its frequency and wavelenght
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With reference to the interaction of electrons from the cathode with atoms of the anode, what percentage of heat typically occurs?
9 Per cent
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The inner envelope of an x-ray tube is usually made from:
Ceramics
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Typical anode angles in general diagnostic X-ray tubes tend to be between:
16 and 20
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The X-ray tube incroporates an angled target in order to:
Decrease the size of the apparent focal spot
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The following material is added to the anode disc of a rotating x-ray tube to prevent the crazing effect
Rhenium
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The added filtration of a diagnostic x- ray tube typically consists of:
Aluminium or copper
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The filtration of an x-ray beam has the effect of
Improving the quality of the transmitted x-ray beam
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When X-rays are produced, the maximum energy of an X-ray photon is determined by the:
keV
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When X-rays are emitted from the X-ray tube, the minimum energy of the radiation beam is determined by the;
mA
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In diagnostic radiography, photoelectric absorption occurs most in;
Bone
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Attenuation of an X-ray beam within matter is not affacted by:
Transmission of X-rays
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Mass attenuation increases with:
Electron density
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The linear attenuation coefficient:
Defines the probability of absorption or scattering process taking place
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The probability of Photoelectric absorption occuring is greatest when:
The energy of the incoming photon is equal to or just above ionisation energy of the atom with which it is interacting
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As the photon energy of an x-ray beam increases:
The incidence of Compton scattering and photoelctric absorption both decrease
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The mass attenuation coefficient is:
Equal to the linear attenuation process divided by the density
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The probability of a Compton interaction is:
Proportional to electron density of the medium
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In the photoelectric absorption process:
The vacancy from the photoelectron is filled by an electron from an orbital (shell) further out in the atom
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## Other cards in this set

### Card 2

#### Front

If the focus of the x-ray tube is 1 mm, the focus is 100cm from the detector and the object is 1 cm from the detector calculate the unsharpness:

0.01 mm

### Card 3

#### Front

The grid ratio is:

### Card 4

#### Front

The voltage of an X-ray beam is conventionally measured in:

### Card 5

#### Front

If a radiographic image requires 20 mAs to produce the required density and the mAs was set at 200 mAs, what is the time setting?