The strength is the ability of a material to resist
Deformation under stress
Externally applied forces with breakdown or yielding
Fracture due to high impact loads
None of these
Correct Answer :
B. Externally applied forces with breakdown or yielding
Related Questions
The ratio of the volume occupied by the atoms to the total volume of the unit cell is called
Coordination number
Atomic packing factor
Space lattice
None of these
A reversible change in the atomic structure of the steel with a corresponding change in the properties is known as
Allotropic change
Recrystallisation
Heat treatment
Precipitation
Which of the following property is desirable for materials used in tools and machines?
Elasticity
Plasticity
Ductility
Malleability
The unit cells
Contain the smallest number of atoms which when taken together have all the properties of the crystals of the particular metal
Have the same orientation and their similar faces are parallel
May be defined as the smallest parallelepiped which could be transposed in three coordinate directions to build up the space lattice
All of the above
Which of the following when used in ordinary low carbon steels, makes the metal ductile and of good bending qualities?
Sulphur
Phosphorus
Manganese
Silicon
Pearlite consists of
13% carbon and 87% ferrite
13% cementite and 87% ferrite
13% ferrite and 87% cementite
6.67% carbon and 93.33% iron
The main alloying elements high speed steel in order of increasing proportion are
Vanadium, chromium, tungsten
Tungsten, titanium, vanadium
Chromium, titanium, vanadium
Tungsten, chromium, titanium
The molecules in a solid move
In a random manner
In a haphazard way
In circular motion
Back and forth like tiny pendulums
Which of the following material has maximum ductility?
Mild steel
Copper
Nickel
Aluminium
The hardness and tensile strength in austenitic stainless steel can be increased by
Hardening and cold working
Normalising
Martempering
Full annealing
Induction hardening is the process of
Hardening surface of work-piece to obtain hard and wear resistant surface
Heating and cooling rapidly
Increasing hardness throughout
Inducing hardness by continuous process
Blast furnace produces following by reduction of iron ore
Cast iron
Pig iron
Wrought iron
Malleable iron
Which is the false statement about wrought iron? It has
High resistance to rusting and corrosion
High ductility
Ability of hold protective coating
Uniform strength in all directions
Nickel in steel
Improves wear resistance, cutting ability and toughness
Refines grain size and produces less tendency to carburisation, improves corrosion and heat resistant properties
Improves cutting ability and reduces hardenability
Gives ductility, toughness, tensile strength and anticorrosion properties
Ductile cast iron
Contains 1.7 to 3.5% carbon in Free State and is obtained by the slow cooling of molten cast iron
Is also known as chilled cast iron and is obtained by cooling rapidly. It is almost unmachinable
Is produced by annealing process. It is soft, tough and easily machined metal
Is produced by small additions of magnesium (or creium) in the ladle. Graphite is in nodular or spheroidal form and is well dispersed throughout the material
The loss of strength in compression with simultaneous gain in strength in tension due to overloading is known as
Hysteresis
Creep
Visco elasticity
Boeschinger effect
Quenching is not necessary when hardening is done by
Case hardening
Flame hardening
Nitriding
Any one of these
In full annealing, the hypo eutectoid steel is heated from 30°C to 50°C above the upper critical temperature and then cooled
In still air
Slowly in the furnace
Suddenly in a suitable cooling medium
Any one of these
Which of the following pipes is least corrosion resistant?
Brass
Mild steel
Cast iron
Wrought iron
Argentite is the principal ore or raw material for
Aluminium
Tin
Zinc
Silver
Foundry crucible is made of
Mild steel
German silver
Lead
Graphite
Cast iron has
High tensile strength
Its elastic limit close to the ultimate breaking strength
High ductility
All of the above
Stress relaxation is the phenomenon
In which parts are not loaded
In which stress remains constant on increasing load
In which deformation tends to loosen the joint and produces a stress reduced
Stress reduces on increasing load
Which is false statement about normalizing? Normalizing is done to
Refine grain structure
Reduce segregation in casting
Improve mechanical properties
Induce stresses
The crystal structure of brass is
F.C.C.
B.C.C.
H.C.P.
Orthorhombic crystalline structure
The lower critical point for all steels is
600°C
700°C
723°C
913°C
Pick up the wrong statement
Aluminium in steel results in excessive grain growth
Manganese in steel induces hardness
Nickel and chromium in steel helps in raising the elastic limit and improve the resilience and ductility
Tungsten in steels improves magnetic properties and hardenability
Aluminium bronze contains aluminium and copper in the ratio of
50 : 50
40 : 60
60 : 40
10 : 90
The ultimate tensile strength of low carbon steel by working at a high strain rate will
Decrease
Increase
Remain constant
First increase and then decrease
There are fourteen atoms in a unit cell of
Body centred cubic space lattice
Face centred cubic space lattice
Close packed hexagonal space lattice
None of these