ANSWERED GRADED A+
The difference between different forms of electromagnetic radiation is their: - correct answer
✔✔ wavelength
Visible light is defined as electromagnetic radiation observed by the human eye and is in the
range of: - correct answer ✔✔ 400 to 700 nanometers
The "candela" is an SI unit that measures: - correct answer ✔✔ the intensity of a light source
As light moves from the source, intensity is reduced. This is because: - correct answer ✔✔ light
becomes more diffused as it moves away from its source
As light strikes a rough or faceted surface, it is: - correct answer ✔✔ reflected in a number of
directions
Light incident on a material: - correct answer ✔✔ may be absorbed, reflected, or transmitted
depending on the material
A luminance difference from a crack in a sound area will produce what is known as: - correct
answer ✔✔ contrast
Field inspections often require the inspector to: - correct answer ✔✔ wear personal safety
equipment, use additional lighting, and be aware of hazards in the inspection area
, The eyes contain photoactive cells, which send signals to the brain that are then formed into an
image. Familiar images are quickly identified by the brain; however, new images of
discontinuities arriving in the brain: - correct answer ✔✔ may be often overlooked and leave
the discontinuities to remain undetected as they are unknown images
White light is: - correct answer ✔✔ a mixture of colors or wavelengths of light
A reflectivity of 0.3 for a transparent material means that: - correct answer ✔✔ 30% of the
incident light is reflected
During a visual test, a contrast between two points on a surface is established by differences in:
- correct answer ✔✔ reflectivity
Artificial light is used for visual testing because: - correct answer ✔✔ it can be controlled and
kept constant
The units of measurement for illumination are the: - correct answer ✔✔ footcandle and lux
Which of the following would have an effect on sensitivity of a direct visual test? - correct
answer ✔✔ corrosion on the surface
Which of the following tools would only be considered when performing remote visual testing?
- correct answer ✔✔ Robotic devices
Visual testing would typically include all of the following except: - correct answer ✔✔
performing a chemical analysis
In general, the minimum light intensity required during weld inspection is: - correct answer ✔✔
100 footcandles