Machine design top 14 mcq
1.The design calculations for members subject to fluctuating loads with the same factor of safety yield the most conservative estimates when using
Goodman relation.
2.If a shaft made from ductile material is subjected to combined bending and twisting moment, calculations based on which one of the following failure theories will give the most conservative value?
Maximum principal stress theory.
3.If the size of a standard specimen for a fatigue testing machine is increased, the endurance limit for the material will
decreases.
4.A solid circular shaft is subjected to pure torsion. The ratio of maximum shear stress to maximum normal stress at any point would be
1 : 1.
5.The maximum distortion energy theory of failure is suitable to predict the failure of which one of the following types of materials ?
Ductile materials.
6.Disruptive strength is the maximum strength of a metal, when
subjected to 3 principal tensile stresses at right angles to one another and of equal magnitude.
7.Who postulated the maximum distortion energy theory?
Mises-Henky.
8.A rotating shaft carrying a unidirectional transverse load is subjected to
Variable bending stress.
9.For bolts of uniform strength, the shank diameter is made equal to
minor diameter of threads.
10.When a nut is tightened by placing a washer below it the bolt will be subjected to
tensile stress.
11.The rivet head used for boiler plate riveting is usually
snap head.
12.The piston rod and the crosshead in a steam engine are usually connected by means of
Cotter joint.
13.For longitudinal joint in boiler, the type of joint used is
butt joint with double cover plate.
14.In a fillet welded joint, the weakest area of the weld is
throat.
