Cluster 1 physics part 2

The number of scattered photons reaching a radiographic imaging receptor most likely decreases with increasing:

Which examination would most likely be performed without a scatter removal grid?

Measuring the charge liberated in a mass of air quantifies:

An exposure of 1 R most likely corresponds to an air kerma (Gy) of

Compression in mammography increases:

Subject contrast is most likely to be affected by the:

The most important factor for maximizing film contrast is most likely the film:

A characteristic curve with a high gamma likely results in images with a high:

Increasing the amount of scatter in a radiograph reduce:

Spatial resolution is important when detecting lesions that are characterized as being:

What fraction of cell damage most likely results from direct action of x-ray radiation?

How many cells exposed to an LD50 dose are most likely to be killed (%)?

Which cells are likely to be the most resistant to ionizing radiation?

The energy lost per unit length along the track of charged particles is most likely measure of:

The radiation weighting factor (wR) is used to convert absorbed dose into:

If the absorbed dose to lungs from radon daughters (i.e., alpha emitters is 10 mGy, the lung equivalent dose (mSv) is:

After an acute whole-body dose of 1 Gy, which effect is most likely to be observed?

The threshold dose (Gy) for the induction of deterministic effects in interventional radiology is likely to be:

The fractioned dose (Gy) that can induce permanent sterility in males is most likely:

Stochastic effects of radiation include:

Which of the following is most sensitive to radiation-induced carcinogenesis?

Which radiation-induced cancers have the shortest latency period in exposed adults?

Which of the following is least likely to affect the fetal dose in a radiographic examination?

All of the following organs have a tissue weighting factor (w) of 0.04 except:

Which is least likely to be categorized as an x-ray detector?

Absorbed x-ray doses may be quantified by heating thermoluminescent dosimeters and measuring the emitted:

When ionization chambers absorb x-rays, they most likely measure the resultant:

Which of the following works on the principle of air ionization?

Which is least likely to be required is designing the shielding for an x-ray room?

These are the purposes of a vacuum x-ray tube; 1. To allow the number and speed of the accelerated electrons to be controlled independently. 2. To serve as a source of secondary electrons. 3. To avoid variation in tube current.

What is the wavelength of red in the region of visible light if its frequency is equal to 4.29 x 1014 Hz? 1. 7000 Å 2. 700 nm 3. 7 x 10-7 m

Refers to the number of electrons flowing per second from the filament to the target:

As the number of electrons that flow from the filament to the target increases, so the qualities of the x-ray beam.

The average amount of current needed to heat the filament wire and the focusing cup is about:

The following are true regarding the function of an autotransformer, except:

It is the emission of electrons resulting from the absorption of thermal energy.

Anode stem of rotating anode x-ray tube is made of what kind of material?

When the high-speed electrons lose energy and interacts with the nucleus of the tungsten atoms, it will produce: 1. Bremsstrahlung radiation 2. General radiation 3. Slowed down radiation

Which of the following statements is true regarding the anode heel effect:

Vaporized tungsten coat on the glass wall of the x-ray tube may result in:

When a high-speed electrons collide with the electrons in the shell of the target tungsten atom, it will produce;

Which of the following circuits supply the power that heats the filament?

Which of the following are true regarding the filament: 1. The filament should never be heated for longer periods than necessary. 2. Vaporization of the filament acts to shorten the life of an x-ray tube. 3. Filament can vaporize and be deposited as an extremely thin coating on the inner surface of the glass wall of the x-ray tube.

This principle is used to produce x-ray tubes capable of withstanding the heat generated by large exposures.

Type of exposure timer that has been developed to eliminate human error by measuring the amount of radiation required to produce the correct exposure for a radiographic examination.

145. It is the variation in the voltage across the x-ray tube expressed as a percentage of the maximum value.

Radiation produced when high-speed electrons interact with metal surfaces other than the focal track of the anode.

The circuit that regulates current flow through the filament of the x-ray tube:

How many changes in a filament voltage would result to a 20% - 30% change in x-ray tube current?

The area of the tungsten target that is bombarded by electrons from the cathode.

These are true statements regarding the x-ray tube, except:

What are the disadvantages of full-wave rectification? 1. Produces low-energy x-ray 2. Produces heat in the target 3. Decreases patient dose

These are the disadvantages of self-rectification, except:

Type of generator used in mobile radiography that must be charge immediately prior to use:

If an impurity with five valence electrons is added to the silicon lattice, then it is:

In self-rectification, the rectifier is the:

A circuit in x-ray generator that requires maximum insulation.

How much power is needed to heat the filament wire to its appropriate temperature?

Which of the following serves as an insulator and prevents sparking between the various components of the transformer assembly?

What is the unit used to measure the energy photons? 1. Electron volt 2. Joule (J) 3. Angstrom

It is the energy acquired by a single electron when crossing one volt.

What are the two types of anode of the x-ray tube? 1. Stationary 2. Rotating 3. Fixed

A device which converts the smoothed DC into a chopped DC.

Generator used in portable x-ray unit that can operate completely without connection to an outside power supply.

What principle is used in autotransformers?

This allows the operator to select the appropriate kVp, mA and exposure time for a particular radiographic examination.

A device that either increases or decreases the voltage in a circuit.

Which of the following units is/are defined as the charge produced in a given mass of air? 1. Gray 2. Sievert 3. Roentgen 4. Rad

Angstrom is a unit of wavelength, an angstrom is equivalent to: 1. 10-10 m 2. 0.0001 μm 3. 0.1 nm

What is the frequency of blue light with a wavelength of 4000 Å?

The attractive force between the positively charged nucleus and the negatively charged electron that keeps the electrons in the atom. 1. Binding force 2. Electron binding energy 3. Centripetal force

A device that counts the number of electrons flowing in a conductor per unit time.

What are the major components of the transformer assembly? 1. Low-voltage transformer 2. High-voltage transformer 3. Rectifiers 4. Oil

The equation used to express the relationship between ultrasound velocity, wavelength and frequency is:

These are true statements regarding tungsten as the target material, except:

It is the distinct bundles of energy and each of these bundles of energy is called: 1. Radiation 2. Photon 3. Quantum

The chemical interactions between various elements are mainly determined by:

Which of the following statements are correct?

Rank the following binding energies from largest to smallest: 1. Electron binding energy for outer-shell electrons 2. Nuclear binding energy 3. Electron binding energy for inner-shell electrons

Lighter nuclides with an excess of neutrons tend to decay by:

When orbital electrons move from an outer shell to an inner shell, which of the following is not true?

Which type of shielding is suspended from the radiographic collimator to absorb the primary beam photons before they reach the reproductive organs? 1. Contact 2. Shadow 3. Flat

What term describes radiation effects which become evident in the descendants of the irradiated individuals?

Which of the following results of irradiation of cell DNA would have the least potential for lethal consequences?

What is the primary purpose of placing a filter in the primary beam of a diagnostic radiographic unit?

Which of the following sets of technical factors would most likely produce the least patient exposure?

Which of the following patients would contribute the highest genetically significant dose as a result of a colon examination?

Which of the following projections would afford the greatest radiation protection to the lens of the patient’s eye?

What term describes the safety measure that assure that automatic exposure control exposures will not reach the x-ray tube limit if improper console settings are made (i.e., tube is centered to an upright bucky while table ion sensors are activated)?

Which of the following filtrations would result in the highest entrance skin exposure to a patient?

Which of the following x-ray generator configurations and ripple factors would produce the highest, average x-ray energy and the lowest patient exposure?

If all other factors remain the same, which of the following would result in the lowest patient exposure dose?

Which of the following are general effects of radiation on the embryo and fetus? 1. Lethality 2. Congenital abnormalities 3. Long-term effects

Which of the following are normally included in radiation effect discussions of the hemopoietic system? 1. Bone marrow 2. Circulating blood 3. Heart

Which of the following may be result of red bone marrow damage due to radiation? 1. Skin erythema 2. Spinal cord myelitis 3. Anemia

Which of the following would be the most likely result of repeatedly subjecting the hands to radiation (such as the early radiologists did) or to treatment for conditions such as ringworm and acne with high dose of low-energy x-rays?

What is the relationship between film/screen combination and patient exposure dose?

What are the purposes of a collimator? 1. Reduce secondary scattered radiation 2. Filtration 3. Restricting the primary beam to the area of interest

Which of the following is a primary cell radiosensitizer?

Which of the following projections would afford the greatest radiation protection to the breast?