Flat spiral springs are used in:
Try it first: pick an option, then read the explanation.
Correct answer: D. watches
Asked in SSC JE 01/03/2017 (Morning)
Detailed Explanation
A flat spiral spring is a strip wound in a plane spiral. Winding it bends the strip and stores energy, which it returns as a nearly steady torque.
Why “watches” Is Correct
That makes it ideal for watches and clocks (the mainspring and hairspring), as well as toys and gramophones.
| Spring type | Typical use |
|---|---|
| Flat spiral | Watches, clocks, toys |
| Leaf (laminated) | Road vehicles, railway wagons |
| Close-coiled helical | Cycle saddles, valves, buffers |
| Disc (Belleville) | Heavy loads in small space |
Why the Other Options Are Wrong
- A. cycles: Cycles use helical springs (saddles, suspension).
- B. road vehicles: Road vehicles use leaf and helical springs.
- C. railway wagons: Railway wagons use leaf and helical springs.
Key Point
Flat spiral spring → watches/clocks; leaf spring → vehicles and wagons.
Key Concepts for Students
- The strip of a spiral spring is in bending.
- Leaf springs carry vehicle loads by bending.
- Helical springs under axial load work in torsion.
Practice more: this is question 5 in Spring MCQs – Part 1. Try the whole set and check every answer instantly.