Top 1000+ Solved Non Destructive Testing and Evaluation MCQ Questions Answer
Q. Natural discontinuities comparable in size to the penetrameter holes shown on aradiograph may not be detected because:
a. Natural discontinuities may contain less dense material than the penetrameter holes
b. Natural discontinuities may be thicker than the penetrameter holes
c. Natural discontinuities do not necessarily have as sharp edges as the penetrameter holes
d. All of the above
Q. If the radiation intensity is 1 Gy/h (100 R/h) at a distance of 152.4 cm (5 feet) from asource, what is the intensity at 610 cm (20 feet)?
a. 0.0625 Gy/h (6.25 R/h)
b. 0.25 Gy/h (25 R/h)
c. 16 Gy/h (1600 R/h)
d. 4 Gy/h (400 R/h)
Q. Fluorescent screens are seldom used in industrial radiography because:
a. Light leaks degrade the film image
b. Film fogging can result if used in the vicinity of fluorescent lights
c. Poor definition and screen mottle can result
d. None of the above
Q. Calculate geometric unsharpness for the following conditions: Source size = 2 mm × 2mm; SFD = 700 mm; test piece thickness = 25 mm
a. 0.6 mm
b. 0.06 mm
c. 6,0 mm
d. 0.15 mm
Q. The gamma factor of Ir-192 is:
a. 1.37 R·h-1·Ci-1at one metre
b. 0.59 R·h-1·Ci-1at one metre
c. 0.0062 R·h-1·Ci-1at one metre
d. 0.38 R·h-1·Ci-1at one metre
Q. A test piece with large differences in thickness would have:
a. High film contrast
b. High subject contrast
c. Low subject contrast
d. Low film contrast
Q. A quantity expressed by the formula, 0.693/(absorption co-efficient) is called:
a. Half value layer
b. Mass attenuation constant
c. Half-life
d. Specific activity
Q. Which of the following techniques would probably reduce the amount of scatteredradiation reaching the film during a radiographic exposure?
a. Using a finer grained film
b. Using a filtered X ray beam
c. Removing lead screens
d. All of the above
Q. A radiographic indication in a weld, characterised by two parallel dark lines in the filmimage, would probably be caused by:
a. Incomplete penetration
b. Lack of fusion
c. Slag inclusions
d. Tungsten inclusions
Q. To produce the sharpest image, which of the following should be true?
a. The radiographic source should be small
b. The radiographic source should be as close as possible to the test piece
c. The planes of the test piece and the film should be at oblique angles to each other
d. All of the above
Q. ‘Undercut’ or ‘burned out’ edges of the test piece film image are caused by:
a. Geometric unsharpness
b. Scattered radiation
c. Inadequate source to film distance
d. Old film
Q. Which of the following is an advantage of gamma ray over X ray sources forradiography?
a. Portability
b. No external power supply needed
c. Ruggedness
d. All of the above
Q. The intensifying effects of fluorescent screens are caused by:
a. Electron emission
b. Light emission
c. Secondary X rays
d. All of the above
Q. If the required X ray exposure time for a 225 kV, 5 mA exposure is 3 minutes,approximately what exposure time would be required at 10 mA?
a. 1/2 minute
b. 1 minute
c. 1.5 minutes
d. 3 minutes