Take A Free ASNT NDT RT Level 3 Practice Test – Quiz Course

1.

Nature of Penetrating Radiation

Atoms of the same element that have different numbers of neutrons are called_______ of the element.

2.

The number of positive charges on the nucleus of an atom equals the:

3.

Unlike beta and alpha particles, neutrons have no:

4.

Radiation scattering increases as:

5.

Interaction Between Penetrating Radiation and Matter

A consequence of a series of single events occurring as a radiation beam passes through a material is a decrease in intensity. The process is called:

6.

Imaging by Film
According to accepted theory, the spots at which the latent image is localized on the emulsion are local concentrations of:

7.

Imaging by Fluorescent Materials
The bunsen-roscoe reciprocity law, which states that the developed film density depends only on the product of radiation intensity times exposure duration, fails for:

8.

Imaging by Electronic Devices

Unlike other commercially available X-ray intensification systems, the direct X-ray pickup tube:

9.

Radiometry
The roentgen is defined as the amount of:

10.

Generators and Tubes os on an integrated System

X-ray generators built to provide X-rays at very low energy levels are used in special areas in nondestructive testing. The single section X-rays tubes in these low voltage units are usually built with thin windows of what material to permit soft X-rays to emerge from the vacuum envelope?

11.

Sources of Electrons

The focusing cup of the cathode in an X-ray tube determines the size of the electron beam by:

12.

Target Materials And Characteristics
Tungsten is the preferred target material for X-ray tubes used in industrial X-ray machines because it provides a double advantage. One ofthe advantages is that:

13.

Equipment Design Considerations

Another way to alleviate the localized heating of the target is with a:

14.

Isotope Sources
Of the isotopes listed below, which is a fission fragment from the induced fission of Ur-235?

15.

Film Principles and properties
Suppose a radiograph is made using film Whose characteristic graph is shown in Figure 4. The film is exposed for 12 mA per minute and has a density of 0.8 in the area of interest. It is desired to increase the density to 2.0.
What milliamperage per minute would produce such a change?

16.

Solid-State Detectors
The obtainable counting speed using a scintillation counter is limited fundamentally by the:

17.

Real-Time imaging
In comparing electronic image intensifier systems that use TV presentation with those using solid-state screens and high-sensitivity closed-circuit TV systems, which of the following statements is false?

18. TV and Optical Systems
A fluoroscopic system for the inspection of welds in 25.4 mm (1 in.) thick steel has the following features:

• X-ray source-to-image plane spacing of 431.8 mm (17 in.);
• X-ray Focal spot size of 3.8 mm (0.15 1n.);
• Steel (weld)-to-image plane spacing of 76.2 mm(3 in.)
• Image plane length of 228.6 mm (9 in.) in the vertical scan direction of TV system used to view image plane and
• TV system with 525 line scans, with image, fully focused on image tubes.

During tests, it is found that this fluoroscopic system does very poorly in resolving wire image quality indicators (IQIs) and imperfections of less than 0.89 mm (0.035 in.) when they are oriented parallel to the horizontal scan lines of the TV. Assuming that the image screen, optical system, and TV frequency response are capable of much better resolution than this,

Which of the following will increase the resolution of the system the most?

19. Other Non film Devices
In the past, several companies have designed TV cameras with large faceplates and phosphors that directly convert the received X-rays to electron scanning-beam variations. The thickness of the glass faceplate is recognized to prevent use at lower kilovoltage applications, but use at higher kilovoltages has never gained acceptance either, compared with other techniques.

Which of the following is not correct for this type of system?

20.

Gaseous Ionization Detectors
One desirable property for a gas to be used in an ionization detector is a:

21.

Instrumentation
An amplifier to be used in a survey instrument designed to measure high levels of radiation should have the following characteristics:

22.

Gasing And Control Processes
69. A system of X-ray thickness gaging in which X-rays are collimated and projected through a test item and the quantity of unabsorbed radiation is measured is referred to as:

23.

Exposure Hazards
Sources of radioactive material used for radiography are required by regulations to be leak tested at intervals not to exceed

24.

Methods of Controlling Radiation Exposure
Distance is an effective means of external radiation protection because:

25.

Operational and Emergency Procedures
Survey instruments used to monitor gamma radiation must be capable of measuring radiation in the range of:

26.

Sensitivity
Radiographic sensitivity depends on the combined effects of two independent factors. One is radiographic contrast; the other is:

27.

Contrast and Definition
Which of the following parameters does not directly affect radiographic definition?

28.

Geometric Factors
Which of the following is not a factor to be considered to reduce geometric unsharpness?

29.

Intensifying Screens
Variation in the thickness of lead screens from 0.1 mm (0.005 in.) to 0.2 mm (0.01 in.):

30.

Scattered Radiation
Which is generally the greater source of scatter radiation?

31.

Source Factors
Short wavelength photons are normally used on thick sections of steel instead of long-wavelength photons because:

32.

Exposure Curves
Which one of the following is not a specific condition which applies to a given exposure chart?

33.

Darkroom Procedures
The frequency with which a developer solution needs replacement is dependent on the rate and density of films processed, but as a rule, the solution should be replaced:

34.

Darkroom Equipment and Chemicals
When using acid to make the stop bath mixture, the acid is added slowly to the water for which the following reasons?

35.

Film Processing
Holding all other parameters constant, an increase in the time of development of a given film will result in a characteristic curve showing:

36.

Illuminator Requirements
Which of the following is not a requirement for illuminators used in the interpretation of radiographs?

37.

Background Lighting
The contrast sensitivity of the human eye is greatest when the surroundings compared to the area of interest on a radiograph have:

38.

Optical Aids
A stereoscope is a device that:

39.

Judging Rodiogrophic Quality Density
The Density of any radiographic image is primarily dependent upon:

40.

Contrast
Which of the following is independent, for most practical purposes, of the wavelength and distribution of the radiation reaching the film?

41.

Definition
By increasing the source to-film distance in a given exposure, the image sharpness is:

42.

Artifacts
When using lead foil intensifying screens, a fuzzy radiographic image is a sign:

43.

Courses and Correction of Unsatisfaclory Rodiogrophs
Omission of the stop bath or rinsing of the film May cause:

44.

Exposure Calculations
If an exposure time of 1 min was necessary using a 1.8 m (6 ft) source-to-film distance for a particular exposure, what time would be necessary if a 0.9 m (3 ft) source-to-film distance is used and all other variables remain the same?

45.

Blocking and Filtering
Filtering an X-ray beam is analogous to:

46.

Multifilm Techniques
The primary purpose of using two or more films of unequal speed in the same cassette is to:

47.

Special Radiographic Techniques
A setup by which an arrangement of prisms or mirrors permits each eye to see but a single one of a pair of radiographs is known as:

48.

Control of Diffroclion Effects
A method for distinguishing between diffraction mottling and other causes of mottling is to:

49.

Gaging
In routine thickness gaging setups using gamma-ray sources, which one of the following radiation detectors is most commonly used?

50.

Discontinuities: Their Causes and Effects
A definite discontinuity that exists because of the imperfect fusion of two streams of metal that have converged is:

51.

Image-Object Relationships
Using geometric enlargement principles, determine the image size if the object is 150 mm (6 in.) in diameter, the source-to-film distance is 910 mm (36 in.), and the source-to-object distance is 760 mm (30 in.).

52.

Moleriol Processing
A consequence of insufficient heat, or the presence of scale on the fusion face of the weld bevel, maybe:

53.

Radiographic Appearance of Discontinuities
A term used to describe the oxides and other solids, which are shown radiographically as elongated or rounded inclusions, is: