375) When an open coiled helical compression spring is subjected to an axial compressive load, the stress induced in the wire is

376) The contact ratio for gears is

377) A feather key is generally

378) If the tearing efficiency of a riveted joint is 50%, then the ratio of diameter of rivet to the pitch is

379) The ratio of circumferential stress to longitudinal stress in a thin cylinder subjected to an internal pressure is