Machine design objective questions with answers part2

Q1. If a load W is applied instantaneously on a bar; then the stress induced in bar will
(A) be independent of ratio of mass of load W to mass of bar (y)
(B) increase with increase in y
(C) decrease with decrease in y
(D) depend on other considerations

Q2. Brittle coating technique is used for
(A) protecting metal against corrosion
(B) protecting metal against wear and tear
(C) experimental stress analysis
(D) non-destructive testing of metals

Q3. Stress concentration is caused due to
(A) variation in properties of material from point to point in a member
(B) pitting at points or areas at which loads on a member are applied
(C) abrupt change of section
(D) all of the above

Q4. The endurance limit of a material with finished surface in comparison to rough surface is
(A) more
(B) less
(C) same
(D) more or less depending on quantum of load

Q5. Plastic flow in ductile materials
(A) increases the seriousness of static load-ing stress concentration
(B) lessens the seriousness of static load¬ing stress concentration
(C) has no effect on it
(D) depends on other considerations

Q6. The maximum stress due to stress concentration in a bar having circular transverse hole, as compared to its static stress without hole will be
(A) same in both cases
(B) 2 times more
(C) 3 times more
(D) 4 times more

Q7. The fatigue life of a part can be improved by
(A) electroplating
(B) polishing
(C) shot peening
(D) heat treating

Q8. Stress concentration in static loading is more serious in
(A) ductile materials
(B) brittle materials
(C) equally serious in both cases
(D) depends on other factors

Q9. Stress concentration in cyclic loading is more serious in
(A) ductile materials
(B) brittle materials
(C) equally serious in both cases
(D) depends on other factors

Q10. Endurance limit or fatigue limit is the maximum stress that a member can withstand for an infinite number of load applications without failure when subjected to
(A) dynamic loading
(B) static loading
(C) combined static and dynamic loading
(D) completely reversed loading

Q11. Pick up wrong statement. Fatigue strength can be increased by
(A) cold working
(B) shot peeing
(C) grinding and lapping surface
(D) hot working

Q12. Which of the following is not correct procedure to increase the fatigue limit
(A) cold working
(B) shot peening
(C) surface decarburisation
(D) under-stressing

Q13. Coaxing is the procedure of increasing
(A) metal strength by cycling
(B) metal hardness by surface treatment
(C) metal resistance to corrosion by coating
(D) fatigue limit by overstressing the metal by successively increasing loadings

Q14. Which is correct statement ? Stress concentration in static loading is
(A) very serious in brittle materials and less serious in ductile materials
(B) very serious in ductile materials and less serious in brittle materials
(C) equally serious in both types of materials
(D) seriousness would depend on other factors

Q15. In Vicker’s hardness testing, the pyramid indentor apex is
(A) 40°
(B) 132°
(C) 136°
(D) 162°

Q16. Which is correct statement ? Stress concentration in cyclic loading is
(A) very serious in brittle materials and less serious in ductile materials
(B) very serious in ductile materials and less serious in brittle materials
(C) equally serious in both types of materials
(D) seriousness would depend on other factors

Q17. In testing a material for endurance strength, it is subjected to
(A) static load
(B) dynamic load
(C) static as well as dynamic load
(D) completely reversed load

Q18. If a material fails below its yield point, failure would be due to
(A) straining
(B) fatigue
(C) creep
(D) sudden loading

Q19. The fatigue limit of a material
(A) is greatly decreased by poor surface conditions
(B) remains same irrespective of surface conditions
(C) depends mainly on core composition
(D) is dependent upon yield strength of material

Q20. Cold working
(A) increases the fatigue strength
(B) decreases the fatigue strength
(C) has no influence on fatigue strength
(D) alone has no influence on fatigue strength