Radiographic Testing Review Questions Flashcards ...

20. At voltages above 400 kV, the use of lead to provide protection may present serious structure as problems.  If this should be a serious problem, which of the following materials would most likely be used as a substitute?
A. Aluminum 
B. Concrete
C. Steel
D. Boron

Level 2Question[Ref] 1Most modern x-ray units (post 's) utilize _____ circuits to provide smooth high voltage supplies to the x-ray tube.[AGFA] a) diode b) triode c) Villard d) thyristor-based 2In a betatron, electrons complete _____ prior to being deflected at a target.[AGFA] a) 1 revolution b) several dozen of revolutions c) tens of thousands of revolutions d) hundreds of thousand revolutions 3In the Van de Graff generator, electrons from the primary electrode are transferred to the high tension electrode via[AGFA] a) a conveyor belt b) alternating electro-magnetic fields c) 1 MeV potential d) osmotic action 4Direct-fluoroscopy, ie. via a mirror or through radiation absorbing glass is suitable for[AGFA] a) thin and or non-metallic specimens b) thick metals c) lead based ceramics d) none of the above 5X-ray television fluoroscopic images of quality equal to film radiography are possible using[AGFA] a) x-ray diffraction b) filtered x-rays c) digitizing and computerized image enhancements d) ultra-fine zinc silicate output phosphors 6In order to check for possible leakage of radioactive material from a cobalt camera the _________ is used.[ASNT] a) TLD b) wipe test c) G-M counter d) DRD 7A radiation detector that indicates the total amount of ionizing radiation received in an area over a period of time is a(n)[ASNT] a) proportional counter b) rate-meter c) integrating radiation detection instrument d) Geiger-counter 8Most thermoluminescence systems use ____ crystals.[ASNT] a) silver bromide b) ferrous sulphate c) lithium fluoride d) zinc sulphide 9Neutrons are classified according to their[ASNT] a) mass b) charge c) spin d) energy 10Which mechanisms are used to detect neutrons?[ASNT] a) (n,à) (n,p) b) (n,d) (n,f) c) (n,ç) d) all of the above can be used 11The first detectable clinical effects of whole body gamma doses would not be seen until exposures of about[Burnham] a) 30æGy b) 30 mGy c) 300 mGy d) mGy 12The so called "sensitive period" during a woman's pregnancy when the fetus is most sensitive to radiation induced abnormalities is[Burnham] a) the first ten days after conception b) ten days to six weeks after conception c) six weeks to three months after conception d) three months until birth 13A small dose of x-radiation received by a pregnant woman will[Burnham] a) result in fetal death b) cause brain damage in the fetus c) increase chances of birth defects d) none of the above 14Which somatic effect of radiation is likely to be considered to have a threshold (non-stochastic)?[Burnham] a) cancer b) erythema (skin reddening) c) serious hereditary ill-health d) leukemia 15Which somatic effect of radiation is likely to be considered to have no threshold (stochastic)[Burnham] a) cataract formation b) erythema (skin reddening) c) benign tumor formation d) none of the above 16When an unstable isotope experiences á decay, the number of neutrons[Friedlander] a) increases by 1 b) decreases by 1 c) increases by 2 d) remains the same 17An isotope has a 12.4 hour half life. If it has an activity of 30mCi at noon today, what was its activity at 3 p.m. yesterday?[Friedlander] a) 110 mCi b) 102 mCi c) 97 mCi d) 88 mCi 18Sr-85 has a 64 day half life. If a sample is presently 200 MBq what was its activity 100 days ago?[Friedlander] a) 589 MBq b) 538 MBq c) 477 MBq d) 369 MBq 19An isotope has a 60 day half life. If its activity is 2GBq today what will its activity be in 3 weeks?[Friedlander] a) 1.14GBq b) 1.57GBq c) 1.61GBq d) 1.77GBq 20If a electron and an alpha particle both had the same energy, the alpha particle would have the greatest[Hall] a) velocity b) frequency c) wavelength d) LET 21If an alpha particle loses 34eV on average for each ion pair it creates, what is the number of ion pairs a 680keV alpha particle can make before coming to rest?[Hall] a) b) c) 20 d) 40 22When radiographing a weld it may be advisable to grind the surface to a smooth or at least clean surface. The purpose of this is to[IIW Handbook] a) reduce exposure time b) ensure uniform density over the total surface c) reduce chance of missing defects d) improve film contrast 23The purpose of indicating distance along a weld on a radiograph by means of lead numbers is to[IIW Handbook] a) correct for parallax b) meet code requirements c) accurately locate defects d) all of the above 24The purpose of the telescopic rod that flips out in front of the window of a spot x-ray tube is to[IIW Handbook] a) centre the x-ray beam on the area of concern b) filter the beam c) protect the beryllium window d) split the x-ray beam in two 25If you use a magnifying lens to assist in viewing a radiograph it is usually 4x to 6x power. If much greater magnification is used[IIW Handbook] a) the high intensity viewer will burn out the retina b) evaluation will be more stringent than code requirements c) film gain will interfere with interpretation d) none of the above 26Mass is not a property of[Training Manual 2] a) x-rays b) beta particles c) alpha particles d) neutrons 27Ultraviolet light has a wavelength that is longer than[Training Manual 2] a) x-rays b) gamma rays c) cosmic rays d) all of the above 28The effect of increasing the frequency of a gamma photon would be to[Training Manual 2] a) increase its wavelength b) increase its velocity c) decrease its wavelength d) decrease its velocity 29The number of electromagnetic waves passing a point per unit time is called[Training Manual 2] a) wavelength b) angstrom unit c) velocity d) frequency 30The electron volt (eV) is a unit of[Training Manual 2] a) electric charge b) power c) energy d) all of the above