646. Wohler test is a destructive test to find out the __________ strength of a prepared metal specimen.
A. Creep
B. Fatigue
C. Endurance
D. Tensile
✅ The correct answer is option B.
648. In BOF, desiliconisation is a first order reaction. So the silicon content of the metal decreases
A. Linearly with time
B. Exponentially with time
C. Logarithmically with time
D. In proportion to the square root of time
✅ The correct answer is option A.
650. The process of removal of scale formed during hot rolling of steel is termed as
A. Descaling
B. Shot blasting
C. Pickling
D. Skimming
✅ The correct answer is option C.
652. Earing is a defect found in steels after the following metal working operation (s).
A. Deep drawing
B. Rolling
C. Extrusion
D. Wire drawing
✅ The correct answer is option A.
654. Which of the following hardness tests does not measure the indentation hardness of metals and alloys ?
A. Vicker’s hardness test
B. Shore sceleroscope test
C. Brinell hardness test
D. Rockwell hardness test
✅ The correct answer is option B.
657. A metalloid possesses the characteristics of both the metals and non-metals. Which of the following is not a metalloid?
A. Arsenic
B. Antimony
C. Lead
D. None of these
✅ The correct answer is option C.
660. Water hammer in pipelines results, when the flowing fluid
A. Has very high velocity
B. Has very high pressure
C. Is brought to rest by gradually closing a valve
D. Is suddenly brought to rest by closing a valve
✅ The correct answer is option D.
663. Milligram of KOH required to saponify 1 gm of oil is called its __________ number.
A. Saponification
B. Acid
C. Precipitation
D. Emulsion
✅ The correct answer is option A.
626. Ganister contains maximum percentage of
A. FeO
B. SiO₂
C. MgO
D. MnO₂
✅ The correct answer is option B.
629. Softening of hardned steel is done by its
A. Normalising
B. Tempering
C. Annealing
D. Carburising
✅ The correct answer is option A.