Mechanical Engineering (MCQs)

Mechanical Engineering (MCQs)

  • Theory of Machine
  • Machine Design
  • Engineering Materials
  • Strength of Materials
  • Engineering Mechanics
  • Engineering Drawing
  • Engineering Thermodynamics
  • Heat and Mass Transfer
  • Hydraulics and Fluid Mechanics in ME

  • Compressors, Gas Turbines and Jet Engines
  • Refrigeration and Air Conditioning
  • Steam Boilers, Engines, Nozzles and Turbines
  • Internal Combustion Engines (I.C. Engines)
  • Power Plant Engineering
  • Automobile Engineering
  • Manufacturing and Production Technology
  • Workshop Technology
  • Industrial Engineering and Production Management

  • Which is false statement about annealing? Annealing is done to_____.

    • A. Relieve stresses
    • B. Harden steel slightly
    • C. Improve machining characteristic
    • D. Soften material
    Answer: Option B.
    Explanation: 

    annealing of steels Increased cold shaping possibilities because intermediate annealing can be utilized to improve the forming properties after the material is compressed during other operations such as cold heading.

    annealing of steels Reduced chance of distortion during secondary operations such as machining.

    annealing of steels Controlled atmosphere annealing decreases the chance of oxidation to annealed parts.

    annealing of steels Improved reaction time and greater control of emergency product need fulfillment.

  • In which of the following cases, consideration of creep is important_____.

    • A. Flywheel of steam engine
    • B. Cast iron pipes
    • C. Cycle chains
    • D. Gas turbine blades
    Answer: Option D.
    Explanation: 

    Gas turbine blade is made up of exotic materials superalloys to withstand in the difficult environment inside the gas turbine .
    As a consequence of operating the gas turbine at high temperature and high stresses, the turbine blades are subjected to certain deformation (creep)

  • The following types of materials are usually the most ductile_____.

    • A. Face centered cubic lattice
    • B. Body centered cubic lattice
    • C. Hexagonal close packed lattice
    • D. All of the above
    Answer: Option A.
    Explanation: 

    A face-centered cubic crystal structure will exhibit more ductility (deform more readily under load before breaking) than a body-centered cubic structure.
    The bcc lattice, although cubic, is not closely packed and forms strong metals. Alpha-iron and tungsten have the bcc form.

  • Bronze is an alloy of_____.

    • A. Copper and zinc
    • B. Copper and tin
    • C. Copper, tin and zinc
    • D. None of these
    Answer: Option B.
    Explanation: 

    Bronze is an alloy consisting primarily of copper, commonly with about 12–12.5% tin and often with the addition of other metals (such as aluminium, manganese, nickel or zinc) and sometimes non-metals or metalloids such as arsenic, phosphorus or silicon.

  • Nimonic contains ______ percentage of nickel as that of Inconel.

    • A. Same
    • B. Less
    • C. More
    • D. None of these
    Answer: Option A.
    Explanation: 

    Nimonic is nickel-based high-temperature low creep superalloys. Nimonic alloys typically consist of more than 50% nickel and 20% chromium with additives such as titanium and aluminium.

  • Iron-carbon alloys containing 1.7 to 4.3% carbon are known as_____.

    • A. Eutectic cast irons
    • B. Hypoeutectic cast irons
    • C. Hypereutectic cast irons
    • D. None of these
    Answer: Option B.
    Explanation: 

    Iron-carbon alloys containing 1.7 to 4.3% carbon are known as Hypoeutectic cast irons

  • The ratio of the volume occupied by the atoms to the total volume of the unit cell is called_____.

    • A. Coordination number
    • B. Atomic packing factor
    • C. Space lattice
    • D. None of these
    Answer: Option B.
    Explanation: 

    The ratio of the volume occupied by the atoms to the total volume of the unit cell is called Atomic packing factor

  • Eutectoid reaction occurs at_____.

    • A. 600°C
    • B. 723°C
    • C. 1147°C
    • D. 1493°C
    Answer: Option B.
    Explanation: 

    in eutectoid reaction, the austenite transforms into a phase mixture of ferrite (containing 0.76% C) and cementite.
    This phase mixture is known as pearlite.
    The eutectoid reaction occurs at a constant temperature.
    This is known as eutectoid temperature and is 727°C

  • Which one of the following metals would work-harden more quickly than the others?

    • A. Copper
    • B. Brass
    • C. Lead
    • D. Silver
    Answer: Option B.
    Explanation: 

    Unlike steel alloys, brass cannot be hardened by heating.
    Brass can only be strain or work-hardened.
    The hardening occurs when the material is worked mechanically, e.g. by cold working.
    The action of force does not harden brass

  • Manganese is added in low carbon steel to_____.

    • A. Make the steel tougher and harder
    • B. Raise the yield point
    • C. Make the steel ductile and of good bending qualities
    • D. All of the above
    Answer: Option C.
    Explanation: 

    The effect of manganese in improving the mechanical properties of steel depends on its carbon content. Manganese also reduces the critical cooling rate during hardening, meaning it increases the hardenability of steel. Its effect on hardenability is higher than other alloying elements. Hadfield steel is recognized for its ability to be work-hardened due to the addition of 10% to 14% of manganese.

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