Which of the following is/are the correct characteristic(s) of an ideal elastic fastening? 1. It should be able to maintain correct and uniform gauge 2. It should be of a very particular type 3. It shall offer elasticity of low level Select the correct answer.
- A1 onlyCorrect
- B2 and 3 only
- C3 only
- D1, 2 and 3
Solution
Concept
Requirements of rail fastenings
Step-by-step solution
1. An ideal fastening must maintain the gauge (statement 1 correct). 2. It should be of a simple, general type and not very particular (statement 2 wrong). 3. It must offer a high degree of elasticity (statement 3 wrong).
Explanation
Elastic fastenings are expected to hold the rail firmly, keep the gauge and absorb vibrations, which needs good elasticity.
Why the other options are wrong
Statements 2 and 3 are contrary to the requirements.
Shortcut
Ideal fastening: gauge + high elasticity + simple.
Common mistake
Accepting low elasticity.
Correct answer: A) 1 only