Description : __________ is the process used for setting up compressive stresses in the surface of a metal to improve its fatigue strength. (A) Lancing (B) Shot peening (C) Slugging (D) Spinning
Last Answer : (B) Shot peening
Description : Cold worked steel parts are normally subjected to (A) Normalising (B) Hardening (C) Annealing (D) Shot peening
Last Answer : (C) Annealing
Description : -The method used to induce a layer of residual compressive stress on the surface of the spring wire, is (A) shot peening (B) burnishing (C) lapping (D) none of the above
Last Answer : (A) shot peening
Description : Reduction in the grain size reduces the __________ of the material. (A) Fatigue resistance (B) Tensile strength (C) Creep resistance (D) All (A), (B) & (C)
Last Answer : (C) Creep resistance
Description : On decreasing the grain size of a polycrystalline material, the property most likely to deteriorate is (A) Creep (B) Toughness (C) Tensile strength (D) Fatigue
Last Answer : (B) Toughnes
Last Answer : (D) All (A), (B) & (C)
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 : Nitriding of a steel part does not increase its (A) Grain size (B) Fatigue limit (C) Surface hardness (D) Wear resistance
Last Answer : Option B
Description : Fatigue strength of a material increases by (A) Having notches in the specimen (B) Rise in temperature (C) Under stressing the specimen (D) Having scratches on the surface
Last Answer : (C) Under stressing the specimen
Description : Pick out the wrong statement. (A) Both annealing and normalising release the internal stresses of the material besides improving the mechanical properties (B) Low carbon steel does not respond to ... are also used for surface hardening (D) Martempering of a material is a hardening process
Last Answer : Option C
Description : _____ is a surface fatigue failure which occurs when the load on the bearing part exceeds the surface endurance strength of the material. (a) Scoring (b) Pitting (c) Corrosion
Last Answer : (b) Pitting
Description : While normal carburising and nitriding surface treatments increase fatigue strength, excessive treatment may decrease the fatigue strength. Why ?
Last Answer : .Normal carburising/nitriding treatments increase volume due to phase transformation at Surface and introduce residual compressive surface stress and thus increase the fatigue strength. By excessive treatment the ... develop in the regions of high tensile stress and lead to early fatigue failure.
Description : While Normal Carburizing And Nit Riding Surface Treatments Increase Fatigue Strength, Excessive Treatment May Decrease The Fatigue Strength. Why?
Last Answer : Normal carburizes/nits riding treatments increases volume due to phase transformation at the surface and introduce residual compressive surface stress and thus increases fatigue strength. By excessive treatment, the ... in the regions of the high tensile stress and lead o early fatigue failure.
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 : Secondary hardening in steels arises out of the (A) Precipitation of fine alloy carbides at high temperatures (B) Refinement of ferrite grain size by working (C) Decomposition of retained austenite upon heat treatment (D) Precipitation of complex inter-metallic upon heat treatment
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 : __________ 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
Last Answer : (C) Strain ageing
Description : Failure of a material is termed as fatigue failure, if it fails below the yield point. The resistance to fatigue failure of a material is measured by the (A) Ultimate tensile strength (U.T.S.) (B) Endurance limit (C) Elastic limit (D) None of these
Last Answer : (B) Endurance limit
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 : Fatigue resistance of a material is measured by the (A) Elastic limit (B) Ultimate tensile strength (C) Young's modulus (D) Endurance limit
Last Answer : (D) Endurance limit
Description : The maximum stress below which a material can withstand an infinite number of cycle of stress, is termed as the (A) Fatigue strength (B) Creep strength (C) Resilience (D) Endurance limit
Last Answer : D) Endurance limit
Description : The highest stress that a material can withstand for a specified length of time without excessive deformation is called the __________ strength. (A) Creep (B) Endurance (C) Fatigue (D) None of these
Last Answer : Option A
Description : Pick up the correct statement from the following: (A) Catalysts are added to assist and accelerate the hardening of resin (B) The fillers are inert materials and they impart strength and hardness (C) Fibrous fillers increase thermal resistance (D) All the above
Last Answer : Answer: Option D
Description : Case hardening of a material is (A) Followed by tempering or carburising (B) Preceded by its tempering (C) Done to get a soft ductile interior with a very hard surface (D) Carried out to get extreme hardness in its core
Last Answer : (D) Carried out to get extreme hardness in its core
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 : 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 : When a material is subjected to fatigue loading, the ratio of the endurance limit to the ultimate tensile strength is (a) 0.20 (b) 0.35 (c) 0.50 (d) 0.65
Last Answer : (c) 0.50
Description : The resistance to fatigue of a material is measured by (a) elastic limit (b) Young's modulus (c) ultimate tensile strength (d) endurance limit
Last Answer : (d) endurance limit
Description : Which of the following is not a characteristic observed in material failure by fatigue fracture? (A) Plastic deformation of material does not occur (B) Initiation of crack from below the surface does ... (D) Presence of both rough & smooth zone with conchoidal markings in smooth zone of the surface
Description : Pick out the wrong statement. (A) Cold cracking of a weld is due to the presence of hydrogen gas in the weld (B) True stress is given by, σ = σE (1 + εE), where σE and εE ... in the iron blast furnace (D) High residual stress at the surface is beneficial for fatigue properties of a material
Description : Hard peening is a) Hammering the weld across the length while the joint is hot b) Hammering the weld along the length while the joint is hot c) Hammering the weld along the length while the joint is cold d) Hammering the weld across the length while the joint is cold
Last Answer : b) Hammering the weld along the length while the joint is hot
Description : Sodium depletion occurs in excessive sweating, and cannot be corrected by drinking water alone. When uncorrected, it may lead to A. Increase of urea in blood B. Swelling of ankles and feet C. Muscle cramps, loss of energy, fatigue and faintness D. Renal failure
Last Answer : ANSWER: C
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 : Wohler test is a destructive test to find out the __________ strength of a prepared metal specimen. (A) Creep (B) Fatigue (C) Endurance (D) Tensile
Last Answer : (B) Fatigue
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 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 : Pick up the correct statement from the following: (A) Water cement paste hardens due to hydration (B) During hardening cement binds the aggregates together (C) Cement provides strength, durability and water tightness to the concrete (D) All the above
Description : Rapid hardening cement attains early strength due to (A) Larger proportion of lime grounded finer than normal cement (B) Lesser proportion of lime grounded coarser than normal cement (C) Lesser proportion of lime grounded finer than normal cement (D) Excess percentage of gypsum
Description : Early attainment of strength in rapid hardening cement is mainly due to (A) Gypsum (B) Finer grinding (C) Tri-calcium silicate (D) Tri-calcium aluminate
Last Answer : Answer: Option B
Description : Assertion A : Pure lime takes a long time to develop adequate strength. Reason R : Pure lime has slow hardening characteristics. Select your answer according to the coding system given below: (A) Both A and R is true ... explanation of A (C) A is true but R is false (D) A is false but R is true
Description : Which of the following cements is expected to have the highest compressive strength after 3 days (a) Ordinary Portland cement (b) Rapid hardening cement (c) High alumina cement (d) Sulphate resisting cement.
Last Answer : (c) High alumina cement
Description : Rapid hardening cement is used (a) Where high early strength is desired (b) Where form work is to be removed as early as possible (c) For construction of road pavements. (d) All of the above
Last Answer : (d) All of the above
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 : .Incresase amount of the non grain material on the straw Walker the walker (a) Decrease (b) Increase (c) Unaffected (d) Equal
Last Answer : b) Increase
Description : Increase amount of non-grain material on the straw walker _______ the walker losses a) Decreases b) Increases c) Unaffected d) Equal
Description : Yield strength of a polycrystalline metal with an average grain size ‘d’, is proportional to (A) d1/2 (B) d-1/2 (C) d (D) d-1
Last Answer : (B) d-1/2
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 : Pick out the correct statement. (A) Stainless steel is nothing but chromium coated steel (B) Hardening of a soft metal can be done by alloying it with another metal or non-metal (C) ... its temporary distortion under the action of applied stress (D) Rusting of iron is not electrochemical in nature
Last Answer : (B) Hardening of a soft metal can be done by alloying it with another metal or non-metal
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 : Spheroidising of a material is a/an __________ process. (A) Normalising (B) Annealing (C) Tempering (D) Hardening
Last Answer : (B) Annealing