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
Correct Answer :
D. 90% magnesium and 9% aluminium with some copper
Related Questions
Free cutting steels
Contain carbon in free from
Require minimum cutting force
Is used where rapid machining is the prime requirement
Can be cut freely
Eutectoid steel consists of
Wholly pearlite
Wholly austenite
Pearlite and ferrite
Pearlite and cementite
Steel containing ferrite and pearlite is
Hard
Soft
Tough
Hard and tough
The molecules in a solid move
In a random manner
In a haphazard way
In circular motion
Back and forth like tiny pendulums
A specimen of aluminium metal when observed under microscope shows
B.C.C. crystalline structure
F.C.C. crystal structure
H.C.P. structure
A complex cubic structure
For a steel containing 0.8% carbon
There is no critical point
There is only one critical point
There are two critical points
There can be any number of critical points
Nickel when added to copper improves
Machinability
Hardness
Hardness and strength
Strength and ductility
Cast iron is characterised by minimum of following percentage of carbon
0.2 %
0.8 %
1.3 %
2 %
White cast iron contains carbon in the form of
Free carbon
Graphite
Cementite
White carbon
Chromium when added to steel __________ the tensile strength.
Does not effect
Decreases
Increases
None of these
Inconel is an alloy of
Nickel, chromium and iron
Nickel, copper
Nickel, Chromium
Nickel, zinc
The percentage carbon content in wrought iron is about
0.02
0.1
02
0.4
The ultimate tensile strength and yield strength of most of the metals, when temperature falls from 0 to 100°C will
Increase
Decrease
Remain same
First increase and then decrease
The portion of the blast furnace below its widest cross-section is called
Hearth
Stack
Bosh
Throat
Pick up wrong statement about wrought iron
It contains carbon of the order of 0 to 0.25%
It melts at 1535°C
It is very soft and ductile
It is made by adding suitable percentage of carbon to molten iron and subjecting the product to repeated hammering and rolling.
Iron ore is, usually, found in the form of
Oxides
Carbonates
Sulphides
All of these
Hardness of martensite is about
RC 65
RC 48
RC 57
RC 80
The crystal of alpha iron is
Body centered cubic
Face centered cubic
Hexagonal close packed
Cubic structure
The hardness of steel increases if it contains
Austenite
Martensite
Pearlite
Cementite
The coke in the charge of blast furnace
Controls the grade of pig iron
Acts as an iron bearing mineral
Supplies heat to reduce ore and melt the iron
Forms a slag by combining with impurities
When medium carbon steel is heated to coarsening temperature
There is no change in grain size
The average grain size is a minimum
The grain size increases very rapidly
The grain size first increases and then decreases very rapidly
Tensile strength of steel can be safely increased by
Adding carbon up to 2.8%
Adding carbon up to 6.3%
Adding carbon up to 0.83%
Adding small quantities of copper
Brass is an alloy of
Copper and zinc
Copper and tin
Copper, tin and zinc
None of these
The alloy used for making electrical resistances and heating elements is
Nichrome
Invar
Magnin
Elinvar
Which of the following has a fine gold colour and is used for imitation jewellery?
Silicon bronze
Aluminium bronze
Gun metal
Babbitt metal
Paramagnetic alpha iron changes to gamma iron at
770°C
910°C
1440°C
1539°C
Bronze is an alloy of
Copper and zinc
Copper and tin
Copper, tin and zinc
None of these
The material in which the atoms are arranged regularly in some directions but not in others, is called
Amorphous material
Mesomorphous material
Crystalline material
None of these
Bell metal contains
70% copper and 30% zinc
90% copper and 10% ti
85 - 92% copper and rest tin with little lead and nickel
70 - 75% copper and rest tin
White cast iron has
Carbon in the form of carbide
Low tensile strength
High compressive strength
All of these