Material Science for Chemical Engineering Mid - II, November - 2014

1.Phase transformations that involve a change in the microstructure can occur through:
  • Diffusion
  • Maintaining the type and number of phases (e.g., solidification of a pure metal, allotropic transformation, recrystallization, grain growth.)
  • Diffusionless
  • All of the above
Answer: D
2.Phase transformation requires which processes:
  • nucleation
  • growth
  • Both a & b
  • Filaments
Answer: C
3.Which is a coarse phase that forms at temperatures close to the eutectoid temperature.
  • spheroidite
  • Pearlite
  • bainite
  • martensite
Answer: A
4.When a sufficient load is applied to a metal or other structural material, it will cause the material to change shape. This change in shape is called
  • deformation
  • transformation
  • demolition
  • modification
Answer: A
5.When the stress is sufficient to permanently deform the metal, it is called
  • elastic deformation
  • plastic deformation
  • rubber deformation
  • visco elastic eformation
Answer: B
6.Materials that can be magnetized, which are also the ones that are strongly attracted to a magnet, are called
  • silicomagnetic
  • ferromagnetic
  • calciomagnetic
  • magnesiomagnetic
Answer: B
7.Depending on the ability of material to undergo plastic deformation before the fracture the fracture modes can be defined into
  • Ductile
  • Brittle
  • Both a & b
  • crack
Answer: C
8.Under fluctuating / cyclic stresses, failure can occur at loads considerably lower than tensile or yield strengths of material under a static load called as
  • Fatigue
  • Strain
  • Stress
  • Fracture
Answer: A
9.Reduction Reaction must have higher potential than the oxidation reaction or they will not form a
  • anodic cell
  • cathodic cell
  • galvanic cell
  • photovoltaic cell
Answer: B
10.Which is the gradual destruction of materials (usually metals) by chemical reaction with their environment.
  • Corrosion
  • Metal dusting
  • Pitting corrosion
  • Passivation
Answer: A
11.During …………., the nuclei grow in size at the expense of the surrounding material
Answer: Growth
12.When cooling proceeds below the eutectoid temperature (727 oC) nucleation of ……………… starts
Answer: Pearlite
13.A very important structure is ……………., which forms when cooling austenite very fast (quenching) to below a maximum temperature that is required for the transformation.
Answer: Martensite
14.A temporary shape change that is self-reversing after the force is removed, so that the object returns to its original shape, is called……………..
Answer: elastic deformation
15.Elastic deformation is a change in shape of a material at low stress that is recoverable after the …………is removed. This type of deformation involves stretching of the bonds, but the atoms do not slip past each other.
Answer: stress
16.An ………………….. is made from a coil of wire that acts as a magnet when an electric current passes through it but stops being a magnet when the current stops.
Answer: electromagnet
17.…………………separation of a body into pieces due to stress, at temperatures below the melting point
Answer: Fracture
18.…………………materials - little plastic deformation and low energy absorption before fracture
Answer: Brittle
19.Plating, painting, and the application of enamel are the most common ……………………..treatments
Answer: Anticorrosion
20.Microbial corrosion, or commonly known as microbiologically influenced corrosion (MIC), is a corrosion caused or promoted by microorganisms, usually ………………..
Answer: chemoautotrophs