Pick the correct statement from the following:
Try it first: pick an option, then read the explanation.
Correct answer: D. All options are correct
Asked in SSC JE 29/01/2018 (Evening)
Detailed Explanation
A helical spring is a wire wound round a cylinder in a helix. Pitch is the axial distance between adjacent coils; the helix angle is the slope of the coil relative to a plane perpendicular to the spring axis.
Why “All options are correct” Is Correct
Statement (a) defines a helical spring, (b) is the defining feature of a close-coiled spring (coils almost touching, helix angle under about 10°), and (c) defines the helix angle. All options are correct.
Why the Other Options Are Wrong
- A. A wire wound in spiral (helical) form is called a helical spring: True, but not the only true statement.
- B. The pitch of a close-coiled spring is very small: True, but not the only true statement.
- C. The angle made by the coil with the horizontal is called the angle of helix: True, but not the only true statement.
Key Point
Close-coiled: very small pitch and helix angle → wire is mainly in torsion under axial load.
Key Concepts for Students
- Open-coiled springs have a large helix angle.
- Pitch = axial length per coil.
- Close-coiled analysis ignores the small helix angle.
Practice more: this is question 1 in Spring MCQs – Part 1. Try the whole set and check every answer instantly.