Top 550+ Solved Machine Design MCQ Questions Answer
Q. The basic design stress adopted for the design of light gauge steel members is
a. the stress at limit of proportionality
b. the yield stress divided by 1.85
c. the yied stress
d. the permissible stress
e. Increasing the diameter of threaded portion
Q. Lewis equation in ears is used to evaluate
a. Tensile stress in bending
b. Compressive stress in bending
c. Creep stress
d. Endurance limit
e. Shear stress on flank
Q. If a machine member is loaded in such a way that the three principal stresses at a point are 600 kg/cm2 tension, 800 kg/cm2 compression and zero. The maximum shear stress at the point will be
a. 400 kg/cm2
b. 800 kg/cm2
c. 600 kg/cm2
d. 1000 kg/cm2
e. 200 kg/cm2
Q. In V-belt drive the belt touches
a. At bottom
b. At sides only
c. Both at bottom as well as sides
d. Anywhere
e. None of the above
Q. Ball bearing type screws
a. Sliding friction is replaced by rolling friction
b. There is a ball bearing provided on the screwed shafts
c. Are self-locking
d. Friction is more
e. Have load bearing capacity for more than vee threads
Q. Stub teeth are provided on gears
a. For high velocity ratios
b. Low noise
c. Large power transmission
d. Improved capability to withstand shock and vibrations
e. All of the above
Q. Which of the following is not the result of cold work?
a. Increased tensile strength
b. Increasing the diameter of threaded portion
c. Reduced ductility
d. Reduced shock resistance
e. Reduced hardness
Q. In a stone jaw crusher the main crank bearings are
a. Taper roller bearings
b. Roller bearings
c. Ball bearings
d. Double row ball bearings
e. Self-aligning ball bearings
Q. The piston of a internal combustion engine is subjected to
a. fully reversed stresses
b. repeated stresses
c. Increasing the diameter of threaded portion
d. partly repeated stresses
e. partly reversed stresses
Q. Spring stiffness is
a. Load carrying capacity of spring
b. Load per unit area of base
c. Load/cross-sectional area of spring
d. Load/unit deflection
e. None of the above
Q. In a central heating system, the seamless copper tubing used has an inside diameter of 20 mm and a wall thickness of 0.6 mm. For a maximum pressure of 1750 Kpa, when allowable stress is 225 Mpa, the safety factor will be
a. 7.7
b. 9.9
c. 3.3
d. 5.5
e. Increasing the diameter of threaded portion
Q. While designing for screw threads care should be taken to provide adequate length of engagement for the screw and nut threads so as to prevent failure of threads in
a. Tension
b. Compression
c. Torque
d. Shear
e. None of the above
Q. In a bolt the plane of shear
a. Should be across threaded portion of the shank
b. Should never be acress threaded portion of the shank
c. Should be parallel to the axis of bolt
d. Should be normal so the threaded portion of the shank
e. None of the above
Q. In case of rivets, the countersunk heads are used to
a. connect unequal sections
b. Increasing the diameter of threaded portion
c. provide a fluish surface
d. connect structural members
e. connect different materials
Q. Bolts in structures are often tightened
a. upto 90% of yield point
b. below yield point
c. Increasing the diameter of threaded portion
d. upto breaking point
e. upto or beyond yield point