The alloy used for making electrical resistances and heating elements is
Nichrome
Invar
Magnin
Elinvar
Correct Answer :
A. Nichrome
Related Questions
Babbitt metal is a
Lead base alloy
Copper base alloy
Tin base alloy
Cadmium base alloy
The heat treatment process used for softening hardened steel is
Carburising
Normalising
Annealing
Tempering
Eutectoid steel consists of
Wholly pearlite
Wholly austenite
Pearlite and ferrite
Pearlite and cementite
Duralumin contains
3.5 to 4.5% copper, 0.4 to 0.7% magnesium, 0.4 to 0.7% manganese and rest aluminium
3.5 to 4.5% copper, 1.2 to 1.7% manganese, 1.8 to 2.3% nickel, 0.6% each of silicon, magnesium and iron, and rest aluminium
4 to 4.5% magnesium, 3 to 4% copper and rest aluminium
5 to 6% tin, 2 to 3% copper and rest aluminium
The elastic stress strain behaviour of rubber is
Linear
Nonlinear
Plastic
No fixed relationship
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
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
The percentage of carbon in pig iron varies from
0.1 to 1.2%
1.5 to 2.5%
2.5 to 4%
4 to 4.5%
Drop forging dies contain carbon of the order of
0.1 to 0.2 %
0.25 to 0.5 %
0.6 to 0.7 %
0.7 to 0.9 %
The steel widely used for motor car crankshafts is
Nickel steel
Chrome steel
Nickel-chrome steel
Silicon steel
Admiralty brass used for steam condenser tubes contains copper and zinc in the following ratio
50 : 50
30 : 70
70 : 30
40 : 60
Cyaniding is the process of
Dipping steel in cyanide bath
Reacting steel surface with cyanide salts
Adding carbon and nitrogen by heat treatment of steel to increase its surface hardness
Obtaining cyanide salts
A small percentage of boron is added to steel in order to
Increase hardenability
Reduce machinability
Increase wear resistance
Increase endurance strength
Beryllium bronze contains
60% copper and 40% beryllium
80% copper and 20% beryllium
97.75% copper and 2.25% beryllium
99% copper and 1% beryllium
Delta-iron occurs between the temperature ranges of
400°C to 600°C
600°C to 900°C
900°C to 1400°C
1400°C to 1530°C
The metal suitable for bearings subjected to heavy loads, is
Silicon bronze
White metal
Monel metal
Phosphor bronze
A reversible change in the atomic structure of steel with corresponding change in the properties is known as
Molecular change
Physical change
Allotropic change
Solidus change
The cupola is used to manufacture
Pig iron
Cast iron
Wrought iron
Steel
Ball bearings are, usually, made from
Low carbon steel
High carbon steel
Medium carbon steel
Chrome steel
Manganese is added in low carbon steel to
Make the steel tougher and harder
Raise the yield point
Make the steel ductile and of good bending qualities
All of the above
Process of Austempering results in
Formation of bainite structure
Carburised structure
Martenistic structure
Lamellar layers of carbide distributed throughout the structure
Body centered cubic space lattice is found in
Zinc, magnesium, cobalt, cadmium, antimony and bismuth
Gamma iron, aluminium, copper, lead, silver and nickel
Alpha iron, tungsten, chromium and molybdenum
None of the above
Inconel contains
65% nickel, 15% chromium and 20% iron
68% nickel, 29% copper and 3% other constituents
80% nickel and 20% chromium
80% nickel, 14% chromium and 6% iron
Ductility of a material can be defined as
Ability to undergo large permanent deformations in compression
Ability to recover its original form
Ability to undergo large permanent deformations in tension
All of the above
Cast iron is manufactured in
Blast furnace
Cupola
Open hearth furnace
Bessemer converter
The usual composition of a soldering alloy is
Tin, lead and small percentage of antimony
Tin and lead
Tin, lead and silver
Tin and copper
An alloy of copper, tin and zinc is known as
Brass
Bronze
Gun metal
Muntz metal
Tungsten when added to steel ________ the critical temperature.
Does not effect
Lowers
Raises
None of these
The metallic structure of mild steel is
Body centred cubic
Face centred cubic
Hexagonal close packed
Cubic structure
According to Indian standard specifications, SG 400/15 means
Spheroidal graphite cast iron with B.H.N. 400 and minimum tensile strength 15 MPa
Spheroidal graphite cast iron with minimum tensile strength 400 MPa and 15 percent elongation
Spheroidal graphite cast iron with minimum compressive strength 400 MPa and 15 percent reduction in area
None of the above