Substitutional Diffusion MCQ

Test your knowledge with important Substitutional Diffusion MCQ and their applications. These MCQs are beneficial for competitive exams too. Explore 30 + more Substitutional Diffusion MCQs at Bissoy

• T/Tm is known as____________
  ক

  Homologous temperature

  খ

  Analogous temperature

  গ

  Hector temperature

  ঘ

  Hetero temperature
• Calculate the total flux of A-atoms across a stationary plane with respect to the specimen from the following parameters? Diffusive flux is given as 3 (moles/m2s) Flux due to velocity of the lattice is given as 4(moles/m2s)
  ক

  7

  খ

  1

  গ

  12

  ঘ

  8
• Calculate the value of D at 1768K from the given parameters? (In 10-6 m2/s) Self-diffusion D° = 83mm2/s Q = 283.4 KJ/mol
  ক

  0.29

  খ

  0.35

  গ

  0.49

  ঘ

  0.67
• If the inter-diffusion coefficient is given as 3m2/s and the L value is given as 2m. Calculate the relaxation time?
  ক

  0.449

  খ

  0.567

  গ

  0.789

  ঘ

  0.345
• If the mole fraction of A and B are given as 1/3 and 2/3 respectively and their respective diffusion coefficient are 6 and 3. Calculate the inter-diffusion coefficient (in m2/s)
  ক

  3

  খ

  4

  গ

  6

  ঘ

  1
• In general it is found that in any given couple, atoms with the lower melting point possess a higher D. (Diffusion Coefficient).
  ক

  True

  খ

  False
• Correlation factor of a simple cubic crystal structure is _______
  ক

  0.65549

  খ

  0.72149

  গ

  0.78145

  ঘ

  0.932
• Correlation factor in interstitial diffusion is _____
  ক

  0.45

  খ

  0.78

  গ

  0

  ঘ

  1
• Vacancy diffusion is slower than interstitial diffusion, because_______
  ক

  Bonding of Interstitial to the surrounding atom is weaker

  খ

  Bonding of Interstitial to the surrounding atom is stronger.

  গ

  More vacancy sites than interstitial sites

  ঘ

  Intermolecular forces are stronger in interstitials
• When atoms migrate by the vacancy process the jumping of an atom into a vacant site can equally well be regarded as the jumping of the vacancy onto the atom.
  ক

  False

  খ

  True
• Which of the following is known as Darkens equation?
  ক

  D’ = Dв*XA + DA*Xв

  খ

  D’ = Dв*Xв + DA*XA

  গ

  D’ = Dв*XA

  ঘ

  D’ = Dв*Xв
• Consider the atomic jump. An atom next to a vacancy can make a jump provided it has enough thermal energy to overcome the activation energy barrier to migration. However, most of the time the adjacent site will not be vacant and the jump will not be possible. The probability that an adjacent site is vacant is given by_________. (X is the probability that any one site is vacant, z is the number of nearest neighbours)
  ক

  X*z

  খ

  X/z

  গ

  X+z

  ঘ

  X-z
• What is the number of nearest neighbours present in FCC metals?
  ক

  12

  খ

  8

  গ

  6

  ঘ

  10
• In FCC metal, the value of α (jump distance) is given by____________ (a is the length of a side of cubic lattice)
  ক

  a

  খ

  √2a

  গ

  a/√2

  ঘ

  2a
• In a substitutional diffusion, the diffusion coefficient can be related to the jump frequency by the equation_______ (α=distance between the planes, Ʈ=jump frequency, f=correlation factor)
  ক

  D = (1/6)*α2*Ʈ

  খ

  D = (1/2)*α2*Ʈ

  গ

  D = f*(1/6)*α2*Ʈ

  ঘ

  D = f*(1/2)*α2*Ʈ