This sets of MCQ's most focuses on design of machine elements questions with answers for preparing your exams...
SET 1 of Design of Machine Elements MCQ
Q.no 1. The causes of stress concentration are
A : Variations in properties of materials
B : Abrupt change in cross section
C : Discontinuities in components
D : any one of the above
Answer:-D : any one of the above
Q.no 2. The Number of stress cycles that the standard specimen can complete before appearance of first fatigue crack is
A : fatigue life
B : endurance limit
C : ultimate strength
D : yield strength
Answer:-A : fatigue life
Q.no 3. A self-locking screw has
A : fine threads
B : coarse threads
C : two nuts
D : coefficient of friction more than tangent of lead angle
Answer:-D : coefficient of friction more than tangent of lead angle
Q.no 4. Stress concentration occurs due to
A : abrupt change in cross-section
B : discontinuities in component
C : internal cracks and flaws
D : any one of the above
Answer:-D : any one of the above
Q.no 5. A knuckle joint is used to transmit
A : axial tensile force only
B : axial tensile or compressive force
C : axial compressive force only
D : combined bending and torsional moment
Answer:-A : axial tensile force only
Q.no 6. Universal coupling is a type of ____
A : Flexible coupling
B : Rigid coupling
C : Both a. and b
D : None of the above
Answer:-A : Flexible coupling
Q.no 7. Which of the following materials has maximum ductility
A : grey cast iron
B : mild steel
C : alloy steel
D : high carbon steel
Answer:-B : mild steel
Q.no 8. When mechanical component is subjected to fluctuating loads, it fails at the stress which is
A : lower than ultimate tensile strength
B : higher than ultimate tensile strength
C : equal to ultimate tensile strength
D : any value of ultimate tensile strength
Answer:-A : lower than ultimate tensile strength
Q.no 9. In a steam engine, the valve rod is connected to an eccentric rod by means of
A : Cotter joint
B : Knuckle joint
C : Universal joint
D : Flange coupling
Answer:-B : Knuckle joint
Q.no 10. In a fusion welding process,
A : only heat is used
B : only pressure is used
C : combination of heat and pressure is used
D : none of these
Answer:-A : only heat is used
SET 1 of Design of Machine Elements MCQ
Q.no 11. The fulcrum pin of lever is designed on the basis of
A : torsional moment
B : axial tensile force
C : bending moment
D : bearing pressure
Answer:-D : bearing pressure
Q.no 12. If the stiffness of parts held together by bolt is too large compared with the stiffness of bolt (hard gasket), then the resultant load on the bolt is equal to
A : initial tension
B : external load
C : sum of initial tension and external load
D : higher of initial tension and external load
Answer:-D : higher of initial tension and external load
Q.no 13. In design of screw jack from buckling considerations, the end conditions are assumed as
A : both ends are hinged
B : both ends are fixed
C : one end fixed and other hinged
D : one end fixed and other free
Answer:-D : one end fixed and other free
Q.no 14. The helix angle in case of closely coiled helical spring is
A : Less than 10°
B : 10° to 15°
C : 15° to 20°
D : More than 20°
Answer:-A : Less than 10°
Q.no 15. If friction angle is 30’ then the maximum efficiency of the screw is
A : 0.33
B : 0.66
C : 0.5
D : Noe of the mentioned
Answer:-A : 0.33
Q.no 16. The maximum amplitude of completely reversed stress that the standard specimen can sustain for 1 million cycles is
A : fatigue life
B : endurance limit
C : ultimate strength
D : yield strength
Answer:-B : endurance limit
Q.no 17. If core diameter of bolt is 13.8cm the it’s nominal diameter is given by?
A : 17.27mm
B : 15.34mm
C : 14.67mm
D : 16.34mm
Answer:-A : 17.27mm
Q.no 18. The spring in which number of leaves, which are held together by U-clips are called as
A : Leaf spring
B : semi-elliptical leaf
C : Helical spring
D : elliptical springs
Answer:-B : semi-elliptical leaf
Q.no 19. The angle of twist for a transmission shaft is inversely proportional to
A : shaft diameter
B : (shaft diameter)2
C : (shaft diameter)3
D : (shaft diameter)4
Answer:-D : (shaft diameter)4
Q.no 20. The spring used in mechanical toys is
A : Leaf spring
B : Spiral spring
C : Helical spring
D : All of these
Answer:-B : Spiral spring
