The temperature at which ferromagnetic alpha iron transforms to paramagnetic alpha iron is _______________?
A. 770°C
B. 910°C
C. 1050°C
D. below recrystallisation temperature
E. above recrystallization temperature
A. 770°C
B. 910°C
C. 1050°C
D. below recrystallisation temperature
E. above recrystallization temperature
A. austenite
B. pearlite
C. ferrite
D. cementlte
E. bainite
A. has a fixed structure under all conditions
B. exists in several crystal forms at different temperatures
C. responds to heat treatment
D. has its atoms distributed in a random pattern
E. none of the above
A material is known as allotropic or polymorphic if it __________________? Read More »
Engineering Materials A. stages at which allotropic forms change
B. stages at which further heating does not increase temperature for some time
C. stages at which properties do not change with increase in temperature
D. there is nothing like points of arrest
E. none of the above
Points of arrest for iron correspond to__________________? Read More »
Engineering Materials A. increase
B. decrease
C. remain same
D. first increase and then decrease
E. show unpredictable behaviour
A. creep
B. hot tempering
C. hot hardness
D. fatigue
E. superhardening
A. elastic properties in all directions
B. stresses induced in all directions
C. thermal properties in all directions
D. electric and magnetic properties in all directions
E. density throughout
Isotropic materials are those which have the same ____________________? Read More »
Engineering Materials A. in which parts are not loaded
B. in which stress remains constant on in-creasing load
C. in which deformation tends to loosen the joint and produces a stress reduced
D. stress reduces on increasing load
E. none of the above
Stress relaxation is- the phenomenon ___________________? Read More »
Engineering Materials A. low carbon steel
B. medium carbon steel
C. high carbon steel
D. alloy steel
E. special steel
Mild steel belongs to the following category___________________? Read More »
Engineering Materials A. ability to undergo large permanent deformations in compression
B. ability to recover its original form
C. ability to undergo large permanent deformations in tension
D. all of the above
E. none of the above
Malleability of a material can be defined as ______________________? Read More »
Engineering Materials