专业英语复习题

1.The thickness of any given material where 50% of the incident energy has been attenuated is known as the:

A)Half-value layer

B)Linear attenuation coefficient

C)Decay rate

D)Mass attenuation coefficient

2.Radiographic inspection should be used for crack detection only when

A)The crack is large

B)The test componet is a casting

C)The test component is a weldment

D)The orientation of the crack is known

3.There are four types of radiation-matter interactions that can contribute to the total attenuation. These are:

A)Compton scattering, pair production, photoelectric absorption, rayleigh scattering

B)Compton scattering, electron exchange, photoelectric absorption, rayleigh scattering

C)Electron exchange, pair production, photoelectric absorption, rayleigh scattering

D)None of the above

4.The number of X-ray or Gamma photons that are transmitted through a material depends on the:

A)Energy of the photons

B)Thickness of the material

C)Atomic number of the material

D)All of the above

5.When penetrating radiation is directed at a material, the radiation intensity decreases:

A) Decreases exponentially with increasing material thickness

B) Increase linearly with increasing material thickness

C) Decrease linearly with increasing material thickness

D) None of the above

6.Radiographic contrast describe:

A) The sharpness of lines in a radiograph

B) The differences in photographic density in a radiograph

C) The average photographic density in a radiograph

D) The difference in density between two different radiographs

7.Image quality indicators are usually placed:

A) Anywhere on the back side of the film

B) On the front side of the film near the primary area of interest

C) On the front side of the test component in an area of similar thickness to the primary area of interest

D) On the back side of the test component in the area of interest

8.After traveling through two half-value layers, the incident radiation has been reduced to:

A) 50%

B) 35%

C) 25%

D) None of the above

9.On a film radiograph, an area of high density in the test component will appear:

A) Lighter than the surrounding area

B) Darker than the surrounding area

C) More defined than the surrounding area

D) Less defined than the sorrounding area

10.Film contrast is determined by:

A) The type of film used

B) The process by which the film was developed

C) The radiation energy used

D) Both A and B

11.The amount of geometric unsharpness in a radiograph is affected by:

A) The source to film distance

B) The source to object distance

C) The size of the source

D) All of the above

12.Ionizing radiation can be used in industrial radiography because the health hazards:

A) Have been eliminated with controls and procedures

B) Are minimized through controls and procedures

C) Are worth the risk

D) Are being ignored

13.Thin sheets of lead foil in contact with the film during exposure increase the film density because:

A) They act as a filter to harden the radiation beam

B) They reduce the amount of scatter radiation

C) Incident radiation liberates electrons which help to expose the film

D) None of the above

14.Which of the following does not affect radiographic contrast?

A) Attenuation differences in the component being inspected

B) The wavelength of the radiaiton used

C) The amount of scattered radiation

D) The level of current used for the exposure

15.Lowering the energy of the radiation used to produce a radiograph will generally result in:

A) Less latitude

B) Higher contrast sensitivity

C) A Longer exposure time

D) All of the above

16.When flaws are in unknown locations, radiography is best suited for the detection of:

A) V olumetric defects such as porosity

B) Tight linear defects such as cracks

C) Material delaminations

D) The flaw type does not matter

17.In order to have a reasonable chance at detecting a discontinuity, the reflective surface of the discontinuity must have a dimension that is at least as long as ________ wavelength.

A) One-half

B) One