Damage to metal surface by mechanical action is called____________________?
(A) Pitting
(B) Corrosion
(C) Erosion
(D) None of these
Stresses encountered in the metal forming processes are less than the _____________ of the material?
(A) Fracture strength
(B) Yield strength
(C) Elastic limit
(D) Limit of proportionality
Materials having ________________ lattice structure are usually the most ductile ?
(A) Body centred cubic (bcc)
(B) Hexagonal close packed (hcp)
(C) Face centred cubic (fcc)
(D) None of these
Presence of nickel & chromium in steel does not raise its _________________?
(A) Elastic limit
(B) Machining properties
(C) Ductility
(D) Resilience
Current employed in resistance welding ranges from ____________________ kVA/cm2?
(A) 1.2 to 2.5
(B) 4.5 to 6.2
(C) 7.5 to 8.5
(D) 10.5 to 15.5
Which of the following has the least value of ultimate tensile strength (UTS) ?
(A) Medium carbon steel
(B) High carbon steel
(C) Cast iron
(D) Wrought iron
With increase in compression ratio, the volumetric efficiency of air compressor____________________?
(A) Increases
(B) Decreases
(C) Remain same
(D) May increase or decrease (depends on the suction pressure)
Compressed dry air is used as the cutting fluid, while machining____________________?
(A) Steel
(B) Cast iron
(C) Aluminium
(D) None of these
Alumina, silica, lime and iron oxide are the basic raw material for the manufacture of Portland cement. The component of Portland cement which first hardens is_____________________?
(A) 5CaO. 3 Al2O3
(B) 3CaO. Al2O3
(C) 3CaO. SiO2
(D) 2CaO. SiO2
The pressure outside a bubble/droplet of liquid is ________________ the internal pressure?
(A) Greater than
(B) Less than
(C) Equal to
(D) Unpredictable; depends on the bubble size