Machine Design on Physics related Questions and Answers

Question :   The cracks in helical springs used in railway carriages usually start on the inner side of the coil because of the fact that 1. it is subjected to a higher stress than the outer side 2. it is more stretched than the outer side during the manufacturing process 3. it is subjected to a higher cyclic loading than the outer side 4. it has a lower curvature than the outer side Answer :   3 - it is subjected to a higher cyclic loading than the outer side