Calculate the bending stress induced in the strip of the helical spring. The spring is subjected to a moment of 1250N-mm with breadth and thickens of the strip being 11mm and 1.5mmm respectively.
(a) 508.8N/mm²
(b) 612.2N/mm²
(c) 606.1N/mm²
(d) 564.3N/mm²
This question was asked to me in a job interview.
I found this question in the Concentric & Spiral Springs topic in Springs of Machine Design