91. During hot working of metals,
porosity of the metal is largely eliminated
grain structure of the metal is refined
mechanical properties are improved due of refinement of grains
all of the above
✅ The correct answer is option D.
Machine Design MCQs
92. The dedendum is the radial distance from the
pitch circle to the top of a tooth
pitch circle to the bottom of a tooth
top of a tooth to the bottom of a tooth
addendum circle to the
✅ The correct answer is option B.
93. Auto frettage is the method of
joining thick cylinders
calculating stresses in thick cylinders
prestressing thick cylinders
increasing the life of
✅ The correct answer is option C.
94. The radial stress across the thickness of a thick cylinder is maximum at the inner surface and zero at the outer surface.
TRUE
FALSE
✅ The correct answer is option A.
95. The flank of the tooth is the
surface of the top of the tooth
surface of the tooth above the pitch surface
surface of the tooth below the pitch surface
width of the tooth mea
✅ The correct answer is option C.
96. A screw is said to be a self locking screw, if its efficiency is
less than 50 %
more than 50%
equal to 50%
none of these
✅ The correct answer is option A.
97. If T1 and T2 are the tensions on the tight and slack sides of the belt respectively, and Tc is the centrifugal tension, then initial tension in the belt is equal to
T1 – T2 + Tc
T1 + T2 + Tc
✅ The correct answer is option D.
98. All stresses produced in a belt are
compressive stresses
tensile stresses
both tensile and compressive stresses
shear stresses
✅ The correct answer is option B.
99. In designing a connecting rod, it is considered like __________ for buckling about Y-axis.
both ends hinged
both ends fixed
one end fixed and the other end hinged
one end fixed and the
✅ The correct answer is option B.
100. According to Rankine’s theory, the failure occurs at a point in a member
when the maximum shear stress in a bi-axial stress system reaches the shear stress at elastic limit in a simple tension test
when the maximum principal stress in a bi-axial stress system reaches the elastic limit of the material in a simple tension test
when the strain energy per unit volume in a bi-axial stress system reaches the strain energy at the elastic limit per unit volume as determined from a simple tension test
when the maximum princ
✅ The correct answer is option B.