Combined carbon in iron makes the metal
Soft and gives coarse grained crystalline structure
Soft and gives a fine grained crystalline structure
Hard and gives a coarse grained crystalline structure
Hard and gives a fine grained crystalline structure
Correct Answer :
D. Hard and gives a fine grained crystalline structure
Related Questions
The alloying element which can replace tungsten in high speed steels is
Nickel
Vanadium
Cobalt
Molybdenum
Basic constituents of Monel metal are
Nickel, copper
Nickel, molybdenum
Zinc, tin, lead
Nickel, lead and tin
Chromium when added to steel __________ the tensile strength.
Does not effect
Decreases
Increases
None of these
When the steel is normalised, its
Yield point increases
Ductility decreases
Ultimate tensile strength increases
All of these
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
Argentite is the principal ore or raw material for
Aluminium
Tin
Zinc
Silver
The alloying element which increases residual magnetism and coercive magnetic force in steel for magnets is
Chromium
Nickel
Vanadium
Cobalt
Dow metal contains
94% aluminium, 4% copper and 0.5% Mn, Mg, Si and Fe
92.5% aluminium and, 4% copper, 2% nickel and 1.5% Mg
90% aluminium and 90% copper
90% magnesium and 9% aluminium with some copper
In basic Bessemer process, the furnace is lined with
Silica bricks
A mixture of tar and burnt dolomite bricks
Both (A) and (B)
None of these
An important property of high silicon (12-18%) cast iron is the high
Hardness
Brittleness
Plasticity
Ductility
The maximum internal diameter of a blast furnace is about
3 m
6 m
9 m
12 m
Malleable cast iron is produced
By adding magnesium to molten cast iron
By quick cooling of molten cast iron
From white cast iron by annealing process
None of these
Brass contains
70% copper and 30% zinc
90% copper and 10% tin
85 - 92% copper and rest tin with little lead and nickel
70 - 75% copper and rest tin
Phosphor bronze contains
0.5% of phosphorous
1% phosphorous
2.5% phosphorous
None of the above
Which of the following material has maximum ductility?
Mild steel
Copper
Nickel
Aluminium
A material is known as allotropic or polymorphic if it
Has a fixed structure under all conditions
Exists in several crystal forms at different temperatures
Responds to heat treatment
Has its atoms distributed in a random pattern
White cast iron has
Carbon in the form of carbide
Low tensile strength
High compressive strength
All of these
Basic solution is one which has pH value
Greater than 7
Equal to 7
Less than 7
pH value has nothing to do with basic solution
The metallic structure of mild steel is
Body centred cubic
Face centred cubic
Hexagonal close packed
Cubic structure
Which is false statement about properties of aluminium?
Modulus of elasticity is fairly low
Wear resistance is very good
Fatigue strength is not high
Creep strength limits its use to fairly low temperatures
According to Indian standard specifications, plain carbon steel designated by 40 C8 means that the carbon content is
0.04 %
0.35 to 0.45 %
0.4 to 0.6 %
0.6 to 0.8 %
Chromium 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
Smelting is the process of
Removing the impurities like clay, sand etc. from the iron ore by washing with water
Expelling moisture, carbon dioxide, sulphur and arsenic from the iron ore by heating in shallow kilns
Reducing the ore with carbon in the presence of a flux
All of the above
An engineer's hammer is made of
Cast iron
Forged steel
Mild steel
High carbon steel
The elastic stress strain behaviour of rubber is
Linear
Nonlinear
Plastic
No fixed relationship
Which of the following statement is wrong?
Steel with 0.8% carbon is wholly pearlite
The amount of cementite increases with the increase in percentage of carbon in iron
A mechanical mixture of 87% cementite and 13% ferrite is called pearlite
The cementite is identified as round particles in the structure
German silver contains
1% silver
2% silver
5% silver
No silver
Pig iron is the name given to
Raw material for blast furnace
Product of blast furnace made by reduction of iron ore
Iron containing huge quantities of carbon
Iron in molten form in the ladles
The cupola is used to manufacture
Pig iron
Cast iron
Wrought iron
Steel
The bond formed by transferring electrons from one atom to another is called
Ionic bond
Covalent bond
Metallic bond
None of these