1. The fatigue limit of steel is around ____ times the ultimate tensile strength.
a) 0.3
b) 5
c) 3
d) 0.5
Explanation: The fatigue limit is different for different materials. For the material steel, the fatigue limit is around 0.5 of its ultimate tensile strength. For materials that are non-ferrous in nature, the fatigue limit can 0.3 or 0.4 of its ultimate tensile strength
2. Which of the following are standard inspection methods of aircraft materials?
a) Radiography and fatigue test
b) Magnaflux and bending inspection
c) Radiography and magnaflux inspection
d) Fatigue and bending inspection
Explanation: It is materials being used in aircraft construction that should not experience failure while usage. Hence, it is crucial for the materials to undergo inspection to detect any cracks or defects. There are two standard inspection methods, they are radiography and magnaflux inspection.
3. Which of the following is a non-destructive way of inspecting materials?
a) Fatigue
b) Radiography
c) Welding
d) Bending
Explanation: Non-destructive testing way of materials refers to a process of inspection where the material is not destroyed or harmed in any way. Radiography is a non-destructive way of inspecting materials
4. When radiographs are produced to detect defects, they show up as ___________
a) tubes
b) dark spots
c) invisible spots
d) light spots
Explanation: Radiography is a non-destructive method of inspecting materials. It is performed by passing either X-rays or gamma-rays through the material being tested. Defects or cracks are obtained in the picture in the form of light spots.
5. What wavelengths are classified as X-rays?
a) 10-6 to 10-25 cm
b) 10-6 to 10-9 cm
c) 10-2 to 10-9 cm
d) 25 to 15cm
Explanation: Different types of rays are classified based on their respective wavelengths. The wavelength bracket in which the rays are considered to fit the category of X-rays is from 10-6 to 10-9 centimeters.
6. X-rays can be used to inspect materials of steel up to a thickness of __________ inches.
a) 3
b) 15
c) 0.3
d) 26
Explanation: X-rays can be used to inspect materials made up of steel sufficiently up to a thickness of three inches. If the material being inspected is not as dense as steel, it can also be tested for a higher thickness value.
7. Gammagraphs are obtained by passing __________ through a material.
a) visible rays
b) uv rays
c) gamma-rays
d) x-rays
Explanation: Gammagraphs are a type of radiographs. Hence, they are non-destructive in nature. They are obtained by passing gamma-rays through a material. Radiographs and Gammagraphs are also called shadow pictures.
8. Gamma-rays are rays that have a wavelength of around ___________
a) 10-11
b) 26
c) 10-2
d) 10-22
Explanation: Rays like gamma-rays, X-rays are classified based on their wavelengths. The wavelength bracket in which the rays are considered to fit the category of gamma-rays is around 10-11 centimeters.
9. Gamma-rays are acquired from ___________
a) Radiograph
b) X-ray
c) U.V
d) Radium
Explanation: Gamma-rays are acquired from radium. It is typically in radium sulphate form. Gamma-rays are rays having a wavelength of around 10-11 centimeters. It takes radium 1580 years to decay to one-half it’s original strength
10. Gammagraphs of steel that is as thick as ___________ inches can be acquired.
a) 4
b) 31
c) 8
d) 15
Explanation: Gammagraphs of steel parts or materials as thick as eight inches can also be acquired. This is higher compared to radiographs with X-rays that can be used for steel as thick as only three inches.