Material Science Mid - II, November - 2014

1.Brittle materials such as castiron, concreate, silicate glasses under tensile stress show ____ deformation to point of fracture
  • Plastic
  • Elastic
  • Uniform
  • Non-uniform
Answer: B
2.The change in young’s modulus of ordinarily elastic materials between OK and melting point is
  • 10-20 % increase
  • No change
  • 10-20% decreases
  • 80-90% decrease
Answer: C
3.In tensile tasts necking starts at
  • Lower yield stress
  • Under yield stress
  • Ultimate tensile stress
  • Just before fracture
Answer: C
4.The methods to increase yield strength of crystalline material are
  • Grain refinement
  • Annealing
  • Surface hardening
  • Normalising
Answer: A
5.Most desirable method of increasing yield strength of mild steel
  • Grain refinement
  • Cold working
  • Solute additions
  • Precipitation hardening
Answer: A
6.Methods which does not improve fatigue resistance of materials
  • Fine garin size
  • Shot peening
  • Polishing surfaced
  • Decar burizing steel
Answer: D
7.Residual stress in interior of tempered glass are
  • Nil
  • Tensile
  • Compressive
  • Highly compressive
Answer: B
8.Pree free coating is required when
  • Coating is noble with respect to protected metal
  • Coating is base with respect to protected metal
  • Coating has same potential as protected metal
  • None of the above
Answer: A
9._______does not harden when cool rapidly
  • Pearlite
  • Marten site
  • Ferrite
  • Austenite
Answer: C
10.The method of improving physical properties of some of non- ferrous alloys by solid state reaction
  • Age hardening
  • Precipitation hardening
  • Surface hardening
  • Both a and b
Answer: D
11.______________ is operation or combination of operations involving heating and cooling of metal or alloy in its solid state with object of changing characteristics of material.
Answer: Heat treatment
12.On heating rubber under tensile force, it _______________.
Answer: Shrinks
13.B.C.C iron, residual carbon occupies the mid points of _____________.
Answer: <100>
14.During stretching of ideal elastomer, its enthalpy __________________.
Answer: Remains constant
15.In tensile test, the engineering stress corresponding to maximum load is called ____________________.
Answer: Tensile strength
16.The melting point of polyethylene is1400c, it will not creep at _____________.
Answer: -1960 c
17.Schottky defect is __________________.
Answer: Purely an Interstitial Defect
18.Giffth equation, fracture stress is proportional to __________________.
Answer: 1/C1/2
19.____________ Steels are mixture of pearlite & lementite.
Answer: Hard
20.Articles which are ___________________ heated have no scale effect.
Answer: Induction