ASNT RT II TEST QUESTIONS WITH CORRECT ANSWERS GRADED A 2024

low voltage x-ray tubes are generally fitted with windows made of: - beryllium a monochromatic x-ray beam is: - a beam consisting of a single wavelength the general method of producing x-rays involves the sudden deceleration of high velocity electrons in a solid body called a: - target if it were necessary to radiograph a 7" thick steel product, which gamma ray source would most likely be used? - co-60 a co-60 gamma source has an approximate practical thickness limit of: - 9" of steel or its equivalent the absorption of gamma rays from a given source when passing through matter depends on the: - atomic number, density, and thickness of the matter the fact that gases, when bombarded by radiation ionize and become electrical conductors make them useful in: - radiation detection equipment the velocity of electrons striking the target in an x-ray tube is a function of the: - voltage difference between the cathode and anode the uneven distribution of developed grains within the emulsion of a processed x-ray film causes the subjective impression of: - graininess the gamma ray intensity at 1 ft from a 1 Ci source of radioactive co-60 is nearest to: - 15 R/h the focal spot in an x-ray tube: - should be as small as possible without unduly shortening the life of the tube in an x-ray tube, the filament and focusing cup are the two essential parts of the: - cathode the quantity of radiation which will produce, by means of ionization, one electrostatic unit of electricity in 0.001293 g of dry air is known as a: - Roentgen the specific activity of an isotopic source is usually measured in: - curies per gram (Ci/g) which isotope has the longest half-life? - Cs- 137 the primary form of energy conversion when electrons strike a target in an x-ray tube results in the production of: - heat the slope of a straight line joining two points of specified densities on a characteristic curve of a film is known as the: - average gradient an x-ray film having wide latitude also has, by definition: - low contrast the purpose of circulating oil in some types of x-ray tubes is to: - dissipate heat an x-ray tube with a small focal spot is considered better than one with a large focal spot when it is desired to obtain: - better definition one method of reducing radiographic contrast is to: - decrease the wavelength of the radiation used thin sheets of lead foil in intimate contact with x-ray film during exposure increases film density because they: - emit electrons when exposed to x- and gamma radiation which help darken the film x-ray tubes are often closed in a shockproof casing in order to: - protect the operator from high- voltage shock an x-ray tube is rated for a maximum of 250 kVp. this tube may be operated at a maximum of: - 250,000 V peak voltage a voltage selector consisting of an iron core transformer with a single winding having a series of taps at various points on the winding is called: - an autotransformer