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PMU - Year 1 Physics - Part 4(A)

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All Questions uploaded word for word from MCQ book. All Credit to Authors. Mistakes due in process may have been made, use and check your work at your own discretion. Only simple writing allowed, i.e Superscript and Subscript absent. Questions missed due to Figure/Diagrams/Text: 11.44.46.57
Sole C
Quiz por Sole C, atualizado more than 1 year ago
Sole C
Criado por Sole C mais de 9 anos atrás
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Resumo de Recurso

Questão 1

Questão
Protons and neutrons in a nucleus are termed:
Responda
  • Beta-particles
  • Photons
  • Nucleons

Questão 2

Questão
Linear attenuation coefficient of photoelectric absorption (photoelectric effect interaction probability) τ is:
Responda
  • Inversely proportional to the atomic number of the element Ζ
  • Inversely proportional to the mass number A
  • Proportional on the density ρ

Questão 3

Questão
Linear attenuation coefficient of photoelectric absorption τ depends strongly (approximately to the 4-th power) on:
Responda
  • The density of substance
  • The atomic number of element Z
  • The temperature of substance - t

Questão 4

Questão
Linear attenuation coefficient for Compton effect (Compton scattering interaction probability) δ is proportional to:
Responda
  • Atomic mass number A
  • Density of substance
  • The ratio A/Z

Questão 5

Questão
Linear attenuation coefficient for Compton effect is proportional to:
Responda
  • pZ4
  • pZ2
  • pZ/A

Questão 6

Questão
Linear attenuation coefficient for pair production (electron-positron production probability) X is proportional to:
Responda
  • Atomic mass number A
  • The square of the atomic number of the element Z2
  • The ratio of A/Z

Questão 7

Questão
Predominant mode of interaction between conventional diagnostic x-ray and biological tissues (Figure 11. not included) is:
Responda
  • Pair production (electron-positron)
  • Photoelectric absorption
  • Compton effect (scattering)

Questão 8

Questão
Interaction of photonic ionizing radiation with matter will
Responda
  • Reduce radiation intensity
  • Not change radiation intensity
  • Increase radiation intensity

Questão 9

Questão
What type of interaction between diagnostic x-rays and matter is improbable:
Responda
  • Photoelectric absorption
  • Pair production (electron-positron)
  • Compton effect

Questão 10

Questão
Consider attenuation of photon beam in water/soft tissue (figure 11. not included). Which statement is true:
Responda
  • Photons may undergo two successive photoelectric transitions
  • Compton scattering has a threshold energy of 1.022 MeV
  • Photoelectric effect increases with photo energies
  • Photoelectric and Compton effects equal at 25 KeV

Questão 11

Questão
Roentgen Rays are:
Responda
  • Photons
  • Electrons
  • Positrons

Questão 12

Questão
Roentgen rays are:
Responda
  • Electromagnetic Radiation:
  • Protons
  • Electrons

Questão 13

Questão
X-rays have
Responda
  • A wavelength longer than that of the visible light
  • Positive Electric Charge
  • Ionizing Capacity

Questão 14

Questão
The wavelength of the roentgen radiation is within the range of:
Responda
  • 380 - 760 nm
  • 0.76 - 1000 µm
  • 10 - 380 µm
  • Less than 10 nm

Questão 15

Questão
X-rays have:
Responda
  • Frequency higher than that of the visible light
  • Direct ionizing capacity
  • Negative electric charge

Questão 16

Questão
Characteristic x-ray radiation:
Responda
  • Has continuous energy spectrum
  • Does not differ from braking radiation spectrum
  • Is obtained from K and L shell electron transitions from high atomic shells.

Questão 17

Questão
Continuous x-ray energy spectrum:
Responda
  • Contains several photons with different energy
  • Does not differ from the characteristic x-ray spectrum
  • Is a result of rapid deceleration of electrons near target nuclei

Questão 18

Questão
Intensity ψ of radiation in x-ray tube is proportional to:
Responda
  • The atomic number Z of anode's material
  • The 3-th power of anode U3/a
  • The 2-nd power of anode I2/a

Questão 19

Questão
Intensity ψ of roentgen radiation (x-ray tube) is proportional to:
Responda
  • The 3-th power of anode voltage U3/a
  • The anode current Ia
  • The 2-nd power of the atomic number Z2 of anodes material.

Questão 20

Questão
Intensity ψ of roentgen radiation (x-ray tube) if proportional to:
Responda
  • Density p of the cathode material
  • The 2-nd power of anode voltage U2/a
  • The 2-nd power of anode current I2/a

Questão 21

Questão
Minimum wavelength λmin (maximum energy) of x-ray tube radiation depends on:
Responda
  • Anode Voltage Ua
  • Anode current
  • The atomic number Z of the element of which anode is made
  • Density p of the material of which cathode is made

Questão 22

Questão
Filters in x-ray apparatus modify:
Responda
  • The minimum wavelength λmin of x-ray braking spectrum
  • The amount of anode Voltage Ua
  • The intensity ψ of roentgen radiation

Questão 23

Questão
Intensity ψ of the Roentgen rays is proportional to:
Responda
  • U2IZ
  • UI2Z
  • UIZ2

Questão 24

Questão
Hardness of x-ray radiation (harder/softer) is changed by:
Responda
  • Anode voltage Ua
  • Beam intensity ψ
  • Anode current Ia

Questão 25

Questão
The relationship between HVL (Half Value Layer) and linear attenuation coefficient µ is
Responda
  • HVL = ln(2)/µ
  • HVL = µ/ln(2)
  • HVL = µ*ln(2)

Questão 26

Questão
Water is said to be soft tissue equivalent with respect to x-ray attenuation. This is because water and soft tissue have approximately the same properties. Which properties are NOT the same? (there are more than one correct answers)
Responda
  • Effective atomic number Zeff
  • Effective molecular weight
  • Physical density p
  • Attenuation Coefficient µ

Questão 27

Questão
The purpose of the introduction of contrast substances in the roentgen diagnostics is to:
Responda
  • Obtain coloring in the roentgenogram and not only black and white images
  • Increasing the contrast between soft tissues
  • Reduce the radiation dose on patients

Questão 28

Questão
Contrast substances in diagnostics radiology will:
Responda
  • Increase contrast between different soft tissues
  • Increase contrast between soft tissues and bones
  • Obliterate cancer cells

Questão 29

Questão
Which of the listed chemical elements provides maximum contrast in diagnostic radiology:
Responda
  • Calcium: Z = 20, p = 1.55 g/cm3
  • Barium: Z = 56, p = 3.5 g/cm3
  • Iodine: Z = 53, p = 4.94 g/cm3

Questão 30

Questão
Roentgen osteo-densitometry (measurement of bone density) is based on which of the following phenomena:
Responda
  • Diffraction of roentgen rays (x-rays)
  • Scattering of roentgen rays (x-rays)
  • Attenuation of Roentgen rays (x-rays)

Questão 31

Questão
Hounsfield Unit (CT number) for bones is equal to:
Responda
  • 0
  • up to (+3000)
  • (-1000)

Questão 32

Questão
Hounsfield unit (CT number) for air is equal to:
Responda
  • 0
  • Up to (+3000)
  • (-1000)

Questão 33

Questão
Hounsfield unit (CT number) for water is equal to:
Responda
  • 0
  • up to (+3000)
  • (-1000)

Questão 34

Questão
Hounsfield unit (CT number) is defined as:
Responda
  • (µ-tissue + µ-water) / µ-water
  • (µ-tissue - µ-water) / µ-water
  • (µ-tissue - µ-water) / µ-tissue

Questão 35

Questão
Predominant x-ray interaction mode in CT scanning is:
Responda
  • Photoelectric absorption & compton scattering
  • Electron-positron pair production & photoelectric absorption
  • Compton scattering & electron-positron pair production

Questão 36

Questão
CT diagnostic imaging is based on the phenomenon of:
Responda
  • Reflection of reoentgean rays at the boundary between different structures
  • Absorption of roentgen rays by tissues exposed to radiation
  • Attenuation of roentgen rays by tissues exposed to radiation

Questão 37

Questão
What is the meaning of "computed" in name of CT (computed tomography)?
Responda
  • Calculation of radiation dose
  • Control of the scanning process
  • Formation of the final image

Questão 38

Questão
Computed tomography uses higher anode voltage compared to conventional roentgenography because
Responda
  • Patients are placed further away from x-ray source
  • Rotation of x-ray tube exposes more massive parts of patients body radiation
  • CT x-ray detectors are less sensitive

Questão 39

Questão
CT exposes pateints to higher radiation doses compared to conventional roentgenography (x-ray imaging) because:
Responda
  • Anode voltage is higher
  • Multiple images are taken
  • Both A and B

Questão 40

Questão
Radionuclides used in "in vivo" radionuclide diagnostics are:
Responda
  • Alpha-radionuclides
  • Beta-radionuclides
  • Gamma-Radionuclides

Questão 41

Questão
What type of radioactivity is related to SPECT radionuclide diagnostics:
Responda
  • Beta
  • Alpha
  • Gamma

Questão 42

Questão
Alpha-rays are a beam of:
Responda
  • Electrons
  • Helium nuclei
  • Positrons

Questão 43

Questão
Radiopharmaceuticals are:
Responda
  • Contrast substances used in MRI
  • Contact gels used in ultrasound diagnostics
  • Chemical compounds containing radioactive isotopes

Questão 44

Questão
The following quantity participates in the law of radioactive decay:
Responda
  • Huddersfield unit (CT-number)
  • Index of refreaction n
  • Linear attenuation coefficient
  • Decay constant

Questão 45

Questão
Half-life T1/2 is defined as:
Responda
  • Energy of gamma-radiation
  • Probability of radioactive decay
  • The time it takes for radioactivity to be reduced by half.

Questão 46

Questão
Isomeric transition is a type of decay that changes:
Responda
  • The atomic number Z of the element
  • The energy of the nucleus
  • The mass number A of the nucleus

Questão 47

Questão
Radionuclides produced in generators have:
Responda
  • Long half-life T1/2
  • Short half-life T1/2
  • High energy gamma-radiation

Questão 48

Questão
Radionuclide generators contain:
Responda
  • Only gamma-radionuclides
  • A meta-stable mother radionuclide
  • A metastable daughter radionuclide
  • Mother (parents) and daughter radionuclides - metastable radionuclides

Questão 49

Questão
Radionuclides are:
Responda
  • Transformers of radiowaves
  • Radioactive nuclei
  • Ultrasound detectors

Questão 50

Questão
How does activity of a radio-pharmaceutical change after sterilization for intravenous application (sterilization time ignored):
Responda
  • Reduces abruptly due to chemical changes
  • Increases abruptly due to chemical changes
  • Remains unchanged

Questão 51

Questão
Radio-pharmaceuticals used in nuclear medicine include:
Responda
  • Elements with radioactive nuclei
  • Transformers of infared rays
  • Sources of ultrasound

Questão 52

Questão
Radio-pharmaceuticals used for "in vivo" diagnostics contain radionuclides with the following mode of radioactivity:
Responda
  • Isometric Transition
  • Beta minus decay
  • Alpha decay

Questão 53

Questão
Time required for intial activity A0 for a radioactive source to decay to 10% is between:
Responda
  • 1 and 2 half-lives
  • 2 and 3 half-lives
  • 3 and 4 half-lives
  • 4 and 5 half-lives

Questão 54

Questão
The decay constant for 182TA is 0.006 day-1. Which is its half life:
Responda
  • 0.006 days
  • 83 days
  • 115 days
  • 167 days

Questão 55

Questão
The phenomenon of radioactivity is associated with:
Responda
  • Decay of atoms
  • Decay of nucleus
  • Fusion of nuclei
  • Emission of valence Orbital electrons

Questão 56

Questão
Electron capture involves:
Responda
  • An electron combining with a neutron
  • A neutron being ejected from the nucleus
  • An electron combining with a proton
  • An electron being ejected from the nucleus

Questão 57

Questão
In alpha decay:
Responda
  • Z and A are unchanged
  • Z decreases by 4 and A decreases by 2
  • Z decreases by 2 and A decreases by 4
  • Z decreases by 4 and A decreases

Questão 58

Questão
Isomeric transition involves:
Responda
  • The emission of a gamma-ray
  • The conversion of a neutron to a proton
  • The conversion of a proton to a neutron
  • Electron Capture

Questão 59

Questão
An alpha-particle consists of:
Responda
  • One proton and two neutron
  • Two proton and one neutron
  • Two proton and two neutron
  • One proton and One neutron

Questão 60

Questão
For pair production interactions it is true that:
Responda
  • Have no energy threshold
  • Occur near the electric field of the nucleus
  • Produce 1.022 MeV annihilation radiation
  • Are important in diagnostic radiology
  • All of the above

Questão 61

Questão
99Tc-m has a half-life t1/2 = 6h. What is the approximate value of 99tc-m decay constant:
Responda
  • 0.12 sec-1
  • 0.12 min-1
  • 0.12 hr-1

Questão 62

Questão
After 40 half-lives have elapsed, the activity A of radionuclide is equal to:
Responda
  • A0/40
  • A0/(2*40)
  • A0/(2 40)

Questão 63

Questão
Polonium-210 has a half-life of 4.5 months, and decays into the stable daughter isotope of lead-206. By measuring the proportion of polonium to lead in a sample, one can establiosh the production date of polonium. If the proportion is 1:15 (Po:Pb), how many months have elapsed since production date?
Responda
  • 3
  • 15
  • 18

Questão 64

Questão
What type of radiation can NOT be detected with scintillation detector?
Responda
  • Alpha particles
  • Beta Particles
  • Gamma Rays

Questão 65

Questão
Ionizing radiation used for "In vivo" radionuclide diagnostics:
Responda
  • Alpha and gamma radiation
  • Beta minus radiation
  • Gamma and annihilation radiation

Questão 66

Questão
Which quantity is NOT a parameter of radionuclides:
Responda
  • Activity A
  • Half-Life T1/2
  • Radiation yield
  • Decay constant

Questão 67

Questão
Activity A is a parameter of:
Responda
  • Laser radiation
  • Radionuclides
  • Radioactive sources

Questão 68

Questão
Why is technetium-99m (99mTC) preferred over iodine-131 (131-I) for thyroid gland diagnostics?
Responda
  • 99mTC is more cost-effective
  • 99mTC has fewer side effects
  • 99mTC is a "pure" gamma source and the radiation is orders of magnitude less
  • Natural deposits of 99mTC exists in some tissues

Questão 69

Questão
1987 an old radiotherapy source of cesium-137 (T1/2 = 30 years) was stolen from an abandoned hospital in the brazilian city of goiania. It was subsequently handled by many people, resulting in four deaths and 249 cases of high radiation exposure. If the activity of the source was 74TBq (Terebecquerels) in 1971, what was the activity in the time of the accident?
Responda
  • 51 TBq
  • 37 TBq
  • 30 TBq

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