RI cw 10

(1)

THE WELDING INSTITUTE

Radiographic Interpretation Assessment

Multi – Choice Question Paper (MSR-ARI-1) Name: ………

1. If an exposure time of 2 minutes were necessary using a 3 metre source-to-film distance for a particular exposure, what time would be necessary if a 6 metre source-to-film distance is used and all other variables remain the same?

a. 12 minutes. b. 4 minutes. c. 8 minutes. d. 6 minutes.

2. The characteristic curve of a fast film superimposed on a graph containing a characteristic curve of a slow film, the fast film will?

a. Will be superimposed on top of the curve for the slow film but with a steeper gradient. b. Will be superimposed on top of the curve for the slow film, but the length of the curve

will be different.

c. Will lie to the right of the curve for the slow film. d. Will lie to the left of the curve for the slow film.

3. If we start with 50 curies of Co60, what will the activity be at the end of 15.9 years? a. 12.5 curies.

b. 6.25 curies. c. 3.125 curies. d. 1.75 curies.

4. In welding which of the following processes may be considered for the welding of very thick materials in excess of 100mm?

a. MMA (SMAW) b. Electro-slag (ESW) c. TIG (GTAW) d. Plasma arc (PAW) 5. What are gamma rays?

a. They are the disintegration of a radionuclide.

b. They are a form of excess energy emitted because of certain disintegrations of a radionuclide.

c. They are the sub-atomic particles which are emitted when a radio-isotope disintegrates

(2)

6. Which of the following types of crack is the most common type encountered, associated with welds made on C-Mn steels?

a. Re-heat cracking. b. Lamellar tearing. c. Solidification cracking. d. Hydrogen related cracks. 7. The number 60 in cobalt 60 is:

a. The number of neutrons added to the number of protons. b. The number of neutrons only.

c. The number of protons only. d. Dictates the element type

8. What is the appearance of diffraction mottle? a. Yellow stain

b. Fine porosity. c. Lightning like d. Pink.

9. The projected (effective) focal spot size of an x-ray tube is determined by: a. F.f.d and o.f.d.

b. The total area of the tungsten target set into the anode.

c. The angle of the tungsten target and the size of the electron beam. d. The distance between cathode and anode.

10. A crater crack may also be described as: a. Cold crack.

b. Tearing. c. Star crack. d. Fatigue crack.

11. Which unit has replaced the Rad? a. The sievert.

b. The roentgen. c. The gray. d. The Becquerel.

12. The absorption of radiation by a material varies:

a. Directly with the square of the distance from the source. b. Directly with the thickness of the material.

(3)

d. In an approximately exponential manner with the thickness of the material. 13. Ytterbium 169 is a gamma source which:

a. Produces relatively good quality radiographs at the correct exposure when compared with radiographs produced with Ir192.

b. Produces very short wave length radiation. c. Generally used with fluorometallic screens. d. All of the above.

14. A trace on a radiograph which shows the relationship between the logarithm of the exposure applied to a photographic film and the resulting photographic density is called: a. A bar chart.

b. An exposure chart. c. A logarithmic chart. d. A characteristic curve. 15. In order to reduce penumbra:

a. The object could be made artificially thicker.

b. The radiation should proceed from as large a focal spot as other considerations will allow.

c. The film should be as far as possible from the object being radiographed.

d. The distance from the radiation source to the film should be as long as practicable. 16. Which of the following are reasons for fixation?

a. To remove the undeveloped silver halides in the emulsion.

b. To dissolve silver halide crystals which have an excessive photographic density. c. To reduce the surface tension of the solution.

d. All of the above.

17. A large source size can be compensated for by: a. Increasing the source-to-specimen distance. b. The addition of lead filters.

c. Increasing the specimen-to-film distance. d. None of the above.

18. What is the relationship between gigabecquerels and curies? a. 3.7 1010_{GBq = 1 Ci}

b. 2.7 1010_{GBq = 1 Ci}

c. 37 GBq = 1 Ci d. 109 GBq = 1 Ci

(4)

19. Lead screens used in industrial radiography:

a. To improve the quality of the radiograph by preferentially reducing the effect of scatter.

b. To reduce exposure times. c. To reduce development times. d. Both a and b.

e. All of the above

20. The steeper the gradient of the straight line portion of a specific films characteristic curve: a. The wider the films latitude.

b. The higher the films definition. c. The higher the film contrast d. The lower the film contrast.

21. Which of the following has no effect on film contrast? a. Wavelength of the radiation used.

b. Film density. c. Film type. d. All of the above.

22. A constant potential circuit of x-ray equipment is known as: a. A half-wave rectified circuit.

b. AC circuit

c. An unrectified circuit. d. A Greinacher circuit.

23. The atomic number of an atom is known as its: a. A number.

b. Atomic mass number. c. Z number.

d. N number.

24. Which of the following isotopes has the longest half-life? a. Caesium 137.

b. Thulium 170 c. Cobalt 60 d. Iridium 192.

(5)

25. When producing radiographs with x-ray equipment, if the kilo-voltage is increased: a. The radiographic contrast decreases.

b. The subject contrast increases. c. The film contrast increases. d. The film contrast decreases.

26. If a satisfactory radiograph has been achieved using the following exposure details, exposure time = 2 min 45 seconds, mA = 3, f.f.d. = 10 inch, calculate a new exposure time for the following changes, mA = 4.5, f.f.d. = 12 inch

a. 1.27 minutes.

b. 2 minutes 38 seconds. c. 2.35 minutes

d. 1 minute 27 seconds.

27. What would be the result if a film is placed in a developer solution and allowed to develop without any agitation and tapping?

a. Dichroic fog and mottling. b. Reticulation and white spots c. Yellow fog and dark spots.

d. Bromide streaking and white spots 28. X-ray and gamma rays are types of:

a. Electromagnetic and ionising radiation. b. Electromagnetic and corpuscular radiation. c. Ionising and corpuscular radiation.

d. All of the above. 29. Inherent unsharpness is:

a. Another term given to penumbra.

b. Is caused through the use of large focal spot sizes.

c. To some degree is always present in a radiographic image. d. All of the above.

30. Which standard is entitled “Non-destructive testing Image quality indicators? a. BS EN 2910

b. BS EN 2600 c. BS EN 1435 d. BS EN 462