Hot hardness of high speed steels increases due to the addition of
A.Tungsten
B.Phosphorous
C.Chromium
D.Vanadium
E.None of the above
Category: Engineering Materials Mcqs
Which of the following factor has the least effect on the electrical conductivity of wires made of copper alloy?
A.Method of forming the wire
B.Temperature
C.Alloying element
D.Intensity of any incident light
The process of production of articles having a soft ductile interior and a very hard surface, is known as
A.Hardening
B.Hardening and tempering
C.Case hardening
D.Hardening and annealing
E.None of the above
A material is known as allotropic or polymoriphic if it
A.Has its atoms distributed in random pattern
B.Exists in several crystal forms at different temperatures
C.Has a fixed structure under all conditions
D.Responds to heat tretment
E.Can be cast
Which of the following is a mesomorphous material?
A.Glass
B.Silver
C.Gold
D.Mica
E.Brass
Which of the following rays are neither deflected by electric field nor by magnetic field?
A.?-rays
B.?-rays
C.?-rays
D.X-rays
E.None of the above
Cold shortness is
A.Too much shrinkage of materials at low temperatures
B.Uneven shrinkage of materials at low temperatures
C.Brittleness of material at low temperature
D.The region where Hooke’s law does not hold good
E.None of the above
Which of the following materials have maximum magnetic permeability?
A.Pure iron
B.4% silicon steel
C.Gram oriented Si-Fe
D.Iron carbide
Brinell and Vickers hardness values are practically identical upto a hardness of
A.10
B.30
C.100
D.300
E.600
When a Ge-crystal is doped with phosphorous atom, it becomes
A.P-type semi-conductor
B.N-type semi-conductor
C.Photo sensitive
D.An insulator
E.A ferite
