Mechanical Behaviour MCQ

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

• Which condition is okay to use in cyclic stresses?
  ক

  Low hardness surface

  খ

  Machined surface

  গ

  High SFE

  ঘ

  Coarse grain structure
• Hard surface materials have low fatigue strength.
  ক

  True

  খ

  False
• Non-ferrous metals have fatigue ratio of 0.35.
  ক

  True

  খ

  False
• For steel, fatigue strength is __________ of tensile value.
  ক

  Twice

  খ

  Thrice

  গ

  Half

  ঘ

  Quarter
• What is a way to introduce compressive residual stresses?
  ক

  Micro cracking

  খ

  Bridging

  গ

  Shot peening

  ঘ

  Heating
• The ___________ part of the cyclic stress assists crack opening and its propagation.
  ক

  Normal

  খ

  Shear

  গ

  Tensile

  ঘ

  Compressive
• What is not improved by case hardening?
  ক

  Surface hardness

  খ

  Wear resistance

  গ

  Flexibility

  ঘ

  Fatigue life
• What improves fatigue strength of the component?
  ক

  Electroplating

  খ

  Buffing

  গ

  Indentation

  ঘ

  Softening
• What decreases fatigue life?
  ক

  C in steel

  খ

  Polishing

  গ

  Strain ageing

  ঘ

  Porosity
• What increases fatigue life?
  ক

  Decarburized region

  খ

  Machine marking

  গ

  Polishing surface

  ঘ

  Inclusions
• What causes an increase in fatigue strength of steel?
  ক

  Vacancies

  খ

  Micro cracking

  গ

  Bridging

  ঘ

  Strain ageing effect
• Which element has a maximum effect on fatigue strength in steel?
  ক

  Ni

  খ

  Ag

  গ

  C

  ঘ

  Au
• The fatigue ductility exponent x is always positive.
  ক

  True

  খ

  False
• A smaller value of x results in _________ value of fatigue life.
  ক

  Smaller

  খ

  Larger

  গ

  Constant

  ঘ

  Zero
• A log-log plot between the plastic strain range against the number of fatigue cycles yields ____________
  ক

  Straight line

  খ

  Parabola

  গ

  Elliptical

  ঘ

  Exponential
• Which law can predict the fatigue life in low cycle fatigue conditions?
  ক

  Paris-Erodogan

  খ

  Wood’s law

  গ

  Orowan’s law

  ঘ

  Coffin-Manson law
• For what purpose low cycle fatigue is an important consideration?
  ক

  Subzero systems

  খ

  High temperature systems

  গ

  High load systems

  ঘ

  Wet systems
• Low cycle fatigue conditions are frequently created where the cyclic stresses are of ________ origin.
  ক

  Kinetic

  খ

  Impact

  গ

  Thermal

  ঘ

  Compressive
• What is the limit for low cycle fatigue?
  ক

  100 cycles

  খ

  103 cycles

  গ

  104 cycles

  ঘ

  1010 cycles
• What term is used for fatigue that occurs with less than 104 or 105 cycles?
  ক

  High cycle fatigue

  খ

  Low cycle fatigue

  গ

  Fatigue limit

  ঘ

  Stage II fatigue
• By decreasing the number of cycles, the allowable stress ________
  ক

  Increases

  খ

  Decreases

  গ

  Remains constant

  ঘ

  First Increases then decreases
• Paris-Erdogan relationship is applicable to some ceramics and plastics along with metals.
  ক

  True

  খ

  False
• Which of the following material fails by both hysteric heating and crack propagation?
  ক

  Nylon

  খ

  Polyethylene

  গ

  Propylene

  ঘ

  PMMA
• Material with a high surface to volume ratio have _________ fatigue life.
  ক

  Very low fatigue life

  খ

  Very high fatigue life

  গ

  Lower fatigue life

  ঘ

  Improved fatigue life
• Stage of crack growth is called _________
  ক

  I stage

  খ

  II stage

  গ

  III stage

  ঘ

  IV stage
• What term is used for initial crack formation during fatigue?
  ক

  Cracking

  খ

  Stage I fatigue

  গ

  Stage II fatigue

  ঘ

  Micro cracking
• Which theory defines fatigue failure using microscopic slip bands?
  ক

  Orowan’s theory

  খ

  Wood’s theory

  গ

  Cottrell’s theory

  ঘ

  Dislocation theory
• Slip band are notch root of _________ dimensions.
  ক

  Micro

  খ

  Macro

  গ

  Nano

  ঘ

  Atomic
• Wood’s theory is described by _________
  ক

  Microscopic voids

  খ

  Microscopic slip bands

  গ

  Weak crystal

  ঘ

  Grain boundaries
• Orowan’s theory is related to _________
  ক

  Grain boundaries

  খ

  Weak crystal

  গ

  Slip band

  ঘ

  Gas pores