Best Mechanical Design Engineering Objective Interview Questions
(1) Pitot tube is used for measurement of
(a) Pressure
(b) Temperature
(c) Discharge
(d) Velocity
Ans.: (d) Velocity
(2) Slow plastic deformation of material under constant stress is
(a) Creep
(b) Fatigue
(c) Endurance
(d) Elastic deformation
Ans.: (a) Creep
(3) Mass balancing is done to
(a) Avoid flutter
(b) Increase bending stress
(c) Reduce drag
(d) Distributing mass on control surface
Ans.: (a) Avoid flutter
(4) Short columns are preferred over long columns from
(a) Strength consideration
(b) Buckling consideration
(c) Weight consideration
(d) None of the above
Ans.: (b) Buckling consideration
(5) Centre of pressure of an aerofoil with an increase of angle of attack will
(a) Move forward
(b) Move backward
(c) Not move
(d) None of the above
Ans.: (a) Move forward
(6) Thermal efficiency of a gas turbine plant as compared to diesel engine plant
(a) Higher
(b) Lower
(c) Same
(d) May be higher or lower
Ans.: (a) Higher
(7) A closed cycle gas turbine works on
(a) Carnot cycle
(b) Rankine cycle
(c) Joule cycle
(d) Atkinson cycle
Ans.: (c) Joule cycle
(8) A bolt of uniform strength can be developed by
(a) Keeping the core dia of threads equal to the dia of unthreaded portion of bolt
(b) Keeping the core dia of threads smaller than the dia of unthreaded portion of bolt
(c) Keeping the nominal dia of threads equal to the dia of unthreaded portion of bolt
(d) None of the above
Ans.: (a) Keeping the core dia of threads equal to the dia of unthreaded portion of bolt
(9) Stress concentration factor is defined as ratio of
(a) Max stress to endurance limit
(b) Nominal stress to endurance limit
(c) Max stress to nominal stress
(d) Nominal stress to max stress
Ans.: (c) Max stress to nominal stress
(10) Principle effect of humidity is
(a) Corrosion
(b) Leaking from sealed enclosures
(c) Permanent set of packing and gaskets
(d) Differential contraction of metal parts
Ans.: (a) Corrosion
(11) Backlash is
(a) Sum of the clearance of two gears
(b) Mutual play between two gears
(c) Amount by which the width of a tooth space exceeds the thickness of the engaging tooth on pitch circle
(d) Any of the above
Ans.: (c) Amount by which the width of a tooth space exceeds the thickness of the engaging tooth on pitch circle
(12) Teflon is used for bearings because of
(a) Low co-efficient of friction
(b) Better heat dissipation
(c) Smaller space constraint
(d) All of the above
Ans.: (a) Low co-efficient of friction
(13) When two elastic bodies collide with each other
(a) Two bodies will momentarily come to rest after collision
(b) The two bodies tend to compress & deform at the surface of contact
(c) Two bodies begins to retain their original shape
(d) All of the above
Ans.: (d) All of the above
(14) Antifriction bearings are
(a) Thick lubricated bearing
(b) Thin lubricated bearing
(c) Ball & roller bearing
(d) Plastic bearing
Ans.: (c) Ball & roller bearing
(15) What is Hertzian stress?
(a) Tensile stress on inner surface of cylinder
(b) Bending stress on two contact surface
(c) Contact stress on two contact surfaces
(d) Shear stress on two contact surfaces
Ans.: (c) Contact stress on two contact surfaces
(16) Mohr’s circle can be used to determine following stress on inclined surface
(a) Principal stresses
(b) Normal stresses
(c) Maximum shear stresses
(d) All of the above
Ans.: (a) Principal stresses
(17) What size of material required for making rolled threads?
(a) Pitch diameter
(b) Root diameter
(c) Major diameter
(d) None
Ans.: (a) Pitch diameter