X-rays can be used to : 1. inspect welded joints between two metal parts of a machine. 2. study structure of crystals. Select the answer using the code given below :
- A.1 only
- B.2 only
- C.Both 1 and 2
- D.Neither 1 nor 2
Correct answer
Explanation
The correct answer is C, Both 1 and 2. X-rays can pass through solid materials and their wavelength is close to the spacing of atoms, so they serve both purposes.
X-rays are electromagnetic waves of very short wavelength, roughly 0.01 to 10 nanometres. In industrial radiography they are passed through a welded joint or casting; cracks, gaps and trapped gas show up on the film or detector, so the weld is inspected without cutting it. Since their wavelength matches the distance between atoms in a crystal, a crystal diffracts X-rays into a pattern from which its structure can be worked out. This is X-ray crystallography, built on Bragg's law, and it revealed the structure of DNA.
Option A is wrong because X-rays are also used to study crystals. Option B is wrong because weld inspection is a standard X-ray use. Option D is wrong because both uses are real.
Exam tip: X-rays are used for medical images, weld and casting checks, airport baggage screening and crystal structure (Bragg's law).
Practice Questions
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- A.nickel
- B.iron
- C.tin
- D.aluminium
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- A.Hydrometer
- B.Hygrometer
- C.Hypsometer
- D.Pycnometer
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Read the full explanation →Which one of the following elements is present in the green pigment of leaves?
- A.Magnesium
- B.Iron
- C.Calcium
- D.Copper
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1. Detection of car crash/collision which results in the deployment of airbags almost instantaneously
2. Detection of accidental free fall of a laptop towards the ground which results in the immediate turning off of the hard drive
3. Detection of the tilt of the smartphone which results in the rotation of display between portrait and landscape mode
In how many of the above actions is the function of accelerometer required?
- A.Only one
- B.Only two
- C.All three
- D.None
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Read the full explanation →Consider the following statements :
1. Carbon fibres are used in the manufacture of components used in automobiles and aircrafts.
2. Carbon fibres once used cannot be recycled.
Which of the statements given above is/are correct?
- A.1 only
- B.2 only
- C.Both 1 and 2
- D.Neither 1 nor 2
Show answer
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