Fatigue limit improvement by over stressing the metal by successively increasing the load is called coaxing. In fatigue failure, the material fails ?

Related Mcqs:

1. Which of the following is not a characteristic observed in material failure by fatigue fracture ?

   A. Plastic deformation of material does not occur
   B. Initiation of crack from below the surface does not occur
   C. Initiation of crack occurs on the surface of the machine part
   D. Presence of both rough & smooth zone with conchoidal markings in smooth zone of the

2. Filler material used in welding should have _________________ as compared to the parent metal to be welded ?

   A. Lower melting temperature
   B. Same melting temperature
   C. Same composition
   D. Both ‘B’ & ‘C’

3. The density of the gases (present in air) decreases with increasing altitude to such an extent, that about 70% of the mass of atmospheric air is found in the lower 5 km. of the atmosphere. This lower region of atmosphere is called the_________________?

   A. Ionosphere
   B. Troposphere
   C. Stratosphere
   D. None of these

4. In an amorphous material, atoms defy any definite atomic structure and exist in random pattern just like in liquid. Which of the following is an amorphous material ?

   A. Tin
   B. Lead
   C. Zinc
   D. Glass

5. Which of the following gases is having the widest explosion limit (about 2 to 81% gas in gasair mixture), rendering it the property of the most explosive gas ?

   A. Hydrogen
   B. Acetylene
   C. Carbon monoxide
   D. Ammonia

6. Maximum permissible limit of mercury in human blood is ______________ micrograms/100 c.c?

   A. 1
   B. 7
   C. 19
   D. 82

7. Tolerable limit of nitrogen oxides in air is _____________ ppm?

   A. 0.1
   B. 1
   C. 5
   D. 25

8. The materials which fracture even at small strains are termed as brittle, while those materials which exhibit an appreciable deformation before failure are termed as__________________?

   A. Rigid
   B. Tough
   C. Ductile
   D. Plastic

9. As the entropy of the universe is increasing, day by day, the work producing capacity of a heat engine is_________________?

   A. Not changed
   B. Decreasing
   C. Increasing
   D. Data sufficient, can’t be predicted

10. Increasing the temperature of an aqueous solution will cause decrease in its________________?

    A. Molality
    B. Mole fraction
    C. Weight percent
    D. Molarity