Top 1000+ Solved Non Destructive Testing and Evaluation MCQ Questions Answer
Q. If 37 GBq (1 Ci), of Ir-92 produces dose rate of 0.59 Gy/h (59000 mR/h) at 30.5 cm (1foot), how much dose in Gy/h (R/h) will 370 GBq (10 Ci) produce at the same distance?
a. 0.59 Gy/h (59000R/h)
b. 0.0059 Gy/h (590 R/h)
c. 5.9 Gy/h (590,000 R/h)
d. 0.00059 Gy/h (59 R/h)
Q. Co-59 becomes Co-60 when it is placed in a nuclear reactor where it captures:
a. A proton
b. Contamination
c. Neutron
d. An electron
Q. Approximately how long would it take for a 370 GBq (10 Ci) Co-60 source to decay to92.5 GBq (2.5 Ci)?
a. 5.3 days
b. 5.3 years
c. 10.6 days
d. 10.6 years
Q. The specific activity of radioactive isotope is expressed in:
a. MeV (million electron-volts)
b. Ci/g (Curies per gram) or Becquerel per kg
c. R/h (Roentgens per hour or gray per hour
d. Counts per minute
Q. The general method of producing X rays involves the sudden deceleration of highvelocity electrons in a solid body called a:
a. Focus cup
b. Filament
c. Target
d. Cathode
Q. The velocity of electrons striking the target in an X ray tube is a function of:
a. The atomic number of the cathode material
b. The atomic number of the filament material
c. The voltage applied
d. The current flow in the tube
Q. The primary form of energy conversion when an X ray tube is energized results in theproduction of:
a. Primary X rays
b. Secondary X ray
c. Short wavelength X ray
d. Heat
Q. The radiation from 37 GBq (1 Ci) of Co-60 (0.145 Gy or 14.5R at 30.5 cm or 1 foot)is attenuated in air to approximately 5mR/h at a distance of approximately:
a. 914.5 cm (30 feet)
b. 1524 cm (50 feet)
c. 3048 cm (100feet)
d. 6096 cm (200 feet)
Q. The standard dose rate of a radioactive isotope is expressed in:
a. Roentgens per hour per curie at any standardised distance not exceeding 75 feet
b. Roentgens per hour per curie per foot
c. Roentgens per hour at a distance of one foot
d. Curies per hour
Q. At 61 cm (two feet) from a radiation source, radiation intensity is 3 Gy/h (300 R/h).What is the Intensity at 244 cm (8 feet) from the source?
a. 0.12 Gy/h (12R/h)
b. 1.2 Gy/h (120 R/h)
c. 0.1875 Gy/h (18.75 R/h)
d. 0.28 Gy/h (28 R/h)
Q. A good Cobalt-60 shot is made on a 7.6 cm (3 inches) steel casting using an exposure time of 10 minutes and a source-to-film distance of 91.5 (36 inches). If it is necessary to change the source-to-film distance to 61 cm (24 inches), what exposure time would produce a similar radiograph if all other conditions remain the same?
a. 1.6 minutes
b. 4.4 minutes
c. 6.4 minutes
d. 8.8 minutes
Q. A radiographic exposure with 3700 GBq (100 Ci) source of Ir-192 using source to filmdistance of 60 cm results in a radiation intensity of 0.12 Gy/h (11.8 R/h) and a radiographic density of 2.5. The intensity of radiation needed to obtain the same density when the source to film distance is changed to120 cm is:
a. 0.472 Gy/h (47.2R/h)
b. 0.118 Gy/h (11.8 R/h)
c. 0.029 Gy/h (2.9 R/h)
d. 0.236 Gy/h (23.6 R/h)
Q. Radiographic equivalence factors for Inconel and 304 stainless steel are 1.4 and 1.0 respectively. What is the approximate equivalent thickness of Inconel requiring the same exposure as 1.27 cm (½ inch) thickness of 304 stainless steel?
a. 1.27 cm (0.50 inches)
b. 1.78 cm (0.70 inches)
c. 0.9 cm (0.36 inches)
d. 3.55 cm (1.40 inches)
Q. The approximate radiographic equivalence factors for steel and copper at 220 kV are 1.0 and 1.4 respectively. If it is desirable to radiograph a 1.27 cm (0.5 inch) piece of copper, what thickness of steel would require about the same exposure characteristics?
a. 1.78 cm (0.7 inches)
b. 0.9 cm (0.35 inches)
c. 3.55 cm (1.4 inches)
d. 2.54 cm (1.0 inch)