__________ of a material results, when its strength is increased &
ductility is decreased by heating at a relatively lower temperature after cold
working.
(A) Solid solution hardening
(B) Screw dislocation
(C) Strain ageing
(D) Twinning

1 Answer

Answer :

(C) Strain ageing

Related questions

Description : Strain hardening effect in a metal subjected to cold working is due to the __________ mechanism. (A) Fracture (B) Dislocation (C) Slip (D) Twinning

Last Answer : (C) Slip

Description : Between 230 and 370°C, blue brittleness is caused in mild steel because of the (A) Immobility of dislocation (B) Strain-ageing (C) Increase in Young's modulus (D) Strain hardening

Last Answer : Option B

Description : Strain hardening effect in metals subjected to cold working is due to the __________ mechanism. (A) Slip (B) Fracture (C) Winning (D) Dislocation

Last Answer : (D) Dislocation

Description : In cold working of metal as compared to its hot working (A) Cracks and blow holes are eliminated (B) Ductility and impact strength improves (C) Appreciable strain hardening is produced (D) Yield stress, hardness and fatigue strength is not at all affected

Last Answer : (C) Appreciable strain hardening is produced

Description : Which of the following phenomenon/ phenomena is/are diffusion controlled? (A) Dislocation climb (B) Cross-slip (C) Twinning (D) Recrystallisation

Last Answer : (D) Recrystallisation

Description : 9. The elastic strain energy of a unit length of an edge dislocation as compared to that of a screw dislocation is (A) More (B) Equal (C) Less (D) Double

Last Answer : Option A

Description : Cold working of a material results in increase in hardness, which is termed as the __________ hardening. (A) Cold (B) Work (C) Age (D) Induction

Last Answer : (B) Work

Description : Work hardening of a material (A) Decreases its tensile strength (B) Decreases its ductility (C) Increases its ductility (D) Does not affect its ductility

Last Answer : (B) Decreases its ductility

Description : Exposure to SO2 containing chimney gases results in the (A) Reduction in strength of leather & cloth (B) Acceleration of corrosion rates of metals (C) Increased drying & hardening time of paints (D) All (A), (B) and (C)

Last Answer : (D) All (A), (B) and (C)

Description : For a cold dilute feed to produce thick viscous liquor, backward feeding as compared to forward feeding results in (A) Increased economy (B) Decreased economy (C) Lower capacity (D) No effect on economy

Last Answer : (A) Increased economy

Description : Choose the correct statement regarding thermal cracking. (A) Moderate changes in operating temperature does not change the depth of cracking (B) Increased residence time results in the decreased ... of lighter hydrocarbons are more (D) Greater depth of cracking gives lower octane number gasoline

Last Answer : (D) Greater depth of cracking gives lower octane number gasoline

Description : Dislocation cross-slip is difficult in those materials, which have (A) Large number of slip systems (B) High work hardening rate (C) Coarse grain size (D) Low stacking fault energy

Last Answer : (D) Low stacking fault energy

Description : The graphite in grey irons exists in the form of flakes which act as stress-raisers under tensile loading and consequently grey irons have relatively low tensile strength and ductility. Still grey iron is extensively used in engineering. Why ?

Last Answer : (a) Cheapness. (B) Low melting point and high fluidity making it suitable for castings of intricate shape. (c) Relatively good erosion and corrosion resistance. (d) High damping capacity, with respect to vibration. (e) Relatively good mechanical properties under compressive loading.

Description : To counteract the bad effects of strain hardening on a cold formed part, it must be (A) Tempered (B) Normalised (C) Annealed (D) Hardened

Last Answer : Option C

Description : The heat treatment process applied to cold formed steel parts is (A) Normalising (B) Tempering (C) Artificial ageing (D) Solution annealing

Last Answer : (D) Solution annealing

Description : The high strength of rapid hardening cement at early stage, is due to its (A) Finer grinding (B) Burning at high temperature (C) Increased lime cement (D) Higher content of tricalcium

Last Answer : Answer: Option C

Description : The hardenability of steel decreases with (A) Decrease in dislocation density (B) Increase in solutionising temperature (C) Increase in strength (D) Decrease in grain size

Last Answer : D) Decrease in grain size

Description : The increase in hardness of metal due to its cold working is termed as the __________ hardening. (A) Work (B) Age (C) Induction (D) Flame

Last Answer : (A) Work

Description : A solid material shows case hardening properties while drying. Which of the following should be controlled to control the drying process? (A) Flow rate of inlet air (B) Relative humidity of outlet air (C) Humidity of inlet air (D) Temperature of the solid

Last Answer : (D) Temperature of the solid

Description : Heating the Hypo-eutectoid steels to 30°C above the upper critical temperature line, soaking at that temperature and then cooling slowly to the room temperature to form a pearlite & ferrite structure is called (A) Tempering (B) Hardening (C) Annealing (D) Normalising

Last Answer : Option C

Description : Pick out the wrong statement about the machinability of metals. Machinability of a metal (A) Decreases with increase in strain hardening tendencies (B) Decreases with increase in hardness, in general (C) Depend on the composition, microstructure and physical & mechanical

Last Answer : Option C

Description : For hot feed, forward feeding as compared to backward feeding results in __________ economy. (A) Increased (B) Decreased (C) No effect on (D) None of these

Last Answer : (A) Increased

Description : Increasing the liquor level in the evaporator results in the (A) Decreased capacity (B) Increase in liquor film co-efficient (C) Decreased effect of hydrostatic head (D) Increased true temperature drop

Last Answer : (A) Decreased capacity

Description : Lowering of condenser temperature (keeping the evaporator temperature constant) in case of vapour compression refrigeration system results in (A) Increased COP (B) Same COP (C) Decreased COP (D) Increased or decreased COP; depending upon the type of refrigerant

Last Answer : (A) Increased COP

Description : Other parameters remaining same, the recrystallisation temperature of an alloy is lowered, when (A) Strain rate is increased (B) Grain size is increased (C) Prior cold deformation is increased (D) Not affected by any of the above parameters

Last Answer : (A) Strain rate is increased

Description : The permanent mode of deformation of a material known as _____________ a) Elasticity b) Plasticity c) Slip deformation d) Twinning deformation

Last Answer : b) Plasticity

Description : High percentage of tricalcium silicate and low percentage of dicalcium silicate in cement results in. (a) Rapid hardening (b) High early strength (c) High heat of generation (d) All the above

Last Answer : (d) All the above

Description : Normalising of an object does not (A) Refine coarse grain structure obtained during hot working (B) Improve ductility (C) Improve yield strength (D) Improve mechanical properties

Last Answer : (B) Improve ductility

Description : The property of material, by which a given amount of energy is absorbed by it without plastic deformation, is called the (A) Resilience (B) Toughness (C) Ductility (D) Impact strength

Last Answer : (A) Resilience

Description : The property of material, by which a given amount of energy is absorbed by it, without plastic deformation, is called (A) Resilience (B) Toughness (C) Ductility (D) Impact strength

Last Answer : (A) Resilience

Description : Which of the following statements are true of the multiple organ dysfunction syndrome (MODS)? A. The two-hit model proposes that secondary MODS may be produced when even a relatively ... intensive care units has decreased owing to increased awareness, prevention, and treatment of the syndrome.

Last Answer : Answer: ABC DISCUSSION: MODS is part of a clinical continuum that begins with the systemic inflammatory response syndrome, which is the host's stress response to any major insult such ... pathogenesis of MODS, the incidence of MODS continues to increase without a significant improvement in outcome

Description : Pick out the wrong statement. (A) The toughness of a material decreases, when it is heated (B) Crane hooks are normally made of wrought iron (C) Cold working of a metal decreases its ... (D) The temperature at which new grains are formed in a metal is known as the recrystallisation temperature

Last Answer : (C) Cold working of a metal decreases its fatigue strength

Description : When the steel is subjected to normalising, its __________ decreases. (A) Yield point (B) Ductility (C) Ultimate tensile strength (UTS)

Last Answer : (B) Ductility

Description : ________ cannot increase the fatigue strength of a material. (A) Grain refining (B) Grain coarsening (C) Surface hardening (D) Shot peening

Last Answer : (B) Grain coarsening

Description : The cement whose strength is a little lower than the ordinary cement during the first three months but attains afterwards the same strength, is known as (A) Low-heat Portland cement (B) Rapid hardening Portland cement (C) Portland blast slag cement (D) Portland pozzolana cement

Last Answer : Answer: Option A

Description : Normalising does not __________ of a metal. (A) Improve machinability & tensile strength (B) Remove internal stresses (C) Refine the structure (D) Remove strains caused by cold working

Last Answer : Option B

Description : Copper has very low (A) Malleability (B) Ductility (C) Tensile strength (D) Thermal & electrical conductivity

Last Answer : (C) Tensile strength

Description : Mild steel is (A) A low carbon steel (0.05 to 0.3% carbon) (B) Highly resistant to corrosion (as much as stainless steel) (C) A high carbon steel (0.5 to 1.5% carbon) (D) Very poor in strength & ductility

Last Answer : (A) A low carbon steel (0.05 to 0.3% carbon)

Description : Cast iron compared to steel is better in (A) Ductility (B) Fluidity & castability (C) Strength (D) Malleability

Last Answer : (B) Fluidity & castability

Description : Wrought iron does not have (A) Uniform strength in all directions (B) Ability to hold protective coating (C) High ductility & corrosion resistance (D) Easily weldable characteristics

Last Answer : Option A

Description : Occurrence of 'case hardening' during drying of a high moisture solid cake __________ the drying rate. (A) Increases (B) Decreases (C) Does not affect

Last Answer : (B) Decreases

Description : The ductility of metal is usually expressed in terms of the: A. Yield strength (point where the material is not longer elastic) B. Percent elongation C. Modulus of elasticity (stiffness of the material)

Last Answer : B. Percent elongation

Description : The percentage elongation and the percentage reduction in area depends upon (a) Tensile strength of the material (b) Ductility of the material (c) Toughness of the material (d) None of these

Last Answer : B

Description : Cold cracking in the heat affected zone of a high strength steel weld can take place because of the (A) Retained austenite (B) Martensite formation (C) Relatively high sulphur content in the base metal (D) Sufficient hydrogen present in the welding arc

Last Answer : (B) Martensite formation

Description : For absorbers, high pressure drop results in (A) Increased efficiency (B) Decreased efficiency (C) High operating cost (D) Better gas liquid contact

Last Answer : (C) High operating cost

Description : An increase in the NH3 /CO2 ratio in urea manufacture results in (A) Increased degree of conversion of CO2 to urea (B) Decreased degree of conversion of NH3 to urea (C) Decreased yield of urea (D) Decreased specific volume of molten mass

Last Answer : (A) Increased degree of conversion of CO2 to urea

Description : During drying of a solid, the critical moisture content increases with (A) Decreased drying rate (B) Increased thickness of the solid (C) Increased drying rate (D) Both (B) and (C)

Last Answer : (D) Both (B) and (C)

Description : The heating time constant of a totally enclosed motor is relatively Select one: a. higher b. lower c. independent of type of enclosure. d. small .

Last Answer : B

Description : Dry powdery solid materials are transported by a __________ conveyor. (A) Belt (B) Bucket (C) Screw (D) None of these

Last Answer : (C) Screw