This set of Casting, Forming and Welding Multiple Choice Questions & Answers (MCQs) focuses on “Radiography”.
1. On what voltage do the X-rays operate?
a) 350 kV
b) 375 kV
c) 400 kV
d) 475 kV
Explanation: The X-ray are waves are having very short wavelength. The object which has to be tested, is exposed to the X-rays, for doing this, high voltage supply is required. The X-rays ideally operate on 400 kV.
2. X-rays are useful in detecting defects in casts up to what thickness?
a) 60 mm
b) 61 mm
c) 62 mm
d) 63 mm
Explanation: The X-rays are waves of high amount of energy in them and are very useful in detection of defects in the casts. They need a high amount of voltage supply for this and are able to detect defects up to a thickness of 62mm.
3. What is the lower range of wavelength of the X-rays?
a) 0.001 x 10-5 cm
b) 0.001 x 10-6 cm
c) 0.001 x 10-7 cm
d) 0.001 x 10-8 cm
Explanation: X-rays are known to be waves with very low amount of wavelength. For the production of X-rays, one may usually need an X-ray tube. The shortest X-ray wavelength is calculated to be 0.001 x 10-8 cm.
4. What is the lower range of wavelength of the X-rays?
a) 40 x 10-7 cm
b) 40 x 10-8 cm
c) 40 x 10-9 cm
d) 40 x 10-10 cm
Explanation: The X-rays are considered to be rays having a short wavelength. These X-rays can be produced with the help of an X-ray tube or a Cobalt-60 isotope. The longest wavelength of an X-ray is 40 x 10-8 cm.
5. Which of the following is not a source of production for gamma rays?
Explanation: Among all the above given isotopes, a Cobalt – 60 isotope, Iridium-192 isotope and a Caesium-167 isotope are mainly used for producing gamma rays but not Americium-241 isotope, it is used for making alpha rays.
6. What should the diameter of a Cobalt-60 source used for producing gamma rays?
a) 2 mm
b) 3 mm
c) 4 mm
d) 5 mm
Explanation: For the production of gamma rays, there are some radioactive particles employed. One of them is a Cobalt-60 isotope. The diameter of the source of this isotope is calculated to be around 3 mm in length.
7. For what thickness of a material, do the X-rays give best results?
a) 50 mm
b) 55 mm
c) 60 mm
d) 65 mm
Explanation: X-rays are considered to be having a larger wavelength as compared to that of gamma rays. Owing to this fact, the penetration power of the X-rays is less. Hence, for a shorter thickness, it would give good detection. The best results are obtained in X-ray detection, when the thickness of the material is below 50mm.
8. Which of the following can be a wavelength of gamma ray?
a) 2 x 10-8 cm
b) 3 x 10-8 cm
c) 4 x 10-8 cm
d) 5 x 10-8 cm
Explanation: Gamma rays are supposedly known to have a shorter wavelength as compared to that of X-rays. The wavelength of gamma rays ranges from 0.005 x 10-8 cm to 3 x 10-8 cm.
9. The film produced by an X-ray is called as a radiograph.
Explanation: The film produced by an X-ray is called as an exograph. The film that is produced using gamma rays is called as gamma graph and the combination of the two is called as a radiograph.
10. The penetration power of X-rays depend only on the wavelength of the radiation.
Explanation: In radiography, there is an X-ray wave used for the non-destructive testing. The penetration power of the X-ray depends not just on the wavelength of the radiation but also on the absorbing power of the material.
Sanfoundry Global Education & Learning Series – Casting, Forming and Welding.
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