Which of the following is an amorphous material?
Mica
Silver
Lead
Glass
Correct Answer :
D. Glass
Related Questions
The carbon in the pig iron varies from
0.1 to 0.5 %
0.5 to 1 %
1 to 5 %
5 to 10 %
Paramagnetic alpha iron changes to gamma iron at
770°C
910°C
1440°C
1539°C
Ferromagnetic alpha iron exists in temperature range of
Below 723°C
770 to 910°C
910 to 1440°C
1400 to 1539°C
Slow plastic deformation of metals under a constant stress is known as
Creep
Fatigue
Endurance
Plastic deformation
Addition of copper to aluminium results in
Improvement of casting characteristics
Improvement of corrosion resistance
One of the best known age and precipitation hardening systems
Improving machinability
If a refractory contains high content of silicon, it means refractory is
Acidic
Basic
Neutral
Brittle
1841 high speed steel contains
Vanadium 4%, chromium 18% and tungsten 1%
Vanadium 1%, chromium 4% and tungsten 18%
Vanadium 18%, chromium 1% and tungsten 4%
None of the above
Which is false statement about tempering? Tempering is done to
Improve machinability
Improve ductility
Improve toughness
Release stresses
The hardness of steel increases if it contains
Pearlite
Ferrite
Cementite
Martensite
When elements like nickel, chromium, copper and molybdenum are added to the molten cast iron, it produces
White cast iron
Nodular cast iron
Malleable cast iron
Alloy cast iron
German silver contains
1% silver
2.5% silver
5% silver
10% silver
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
Which of the following alloys does not have copper as one of the constituents?
Delta metal
Monel metal
Constantan
Nichrome
Silicon when added to copper improves
Machinability
Hardness
Hardness and strength
Strength and ductility
Normalising of steel is done to
Refine the grain structure
Remove strains caused by cold working
Remove dislocations caused in the internal structure due to hot working
All of the above
Super conduction by metals is observed in the temperature range of
Below 10°K
Above 100°K
Around 0°C
Around 100°C
The material in which the atoms are arranged chaotically, is called
Amorphous material
Mesomorphous material
Crystalline material
None of these
Sulphur in steel
Acts as deoxidiser
Reduces the grain size
Decreases tensile strength and hardness
Lowers the toughness and transverse ductility
Cold rolled steel sheets contain carbon of the following order
0.1 %
0.2 %
0.4 %
0.6 %
Which one of the following metals would work-harden more quickly than the others?
Copper
Brass
Lead
Silver
Which of the following statements are true for annealing of steels?
Steels are heated to 500 to 700°C
Cooling is done slowly and steadily
Internal stresses are relieved
All of these
Maximum percentage of carbon in austenite is
0.025 %
0.26 %
0.8 %
1.7 %
Pick up the wrong statement Nickel and chromium in steel help in
Providing corrosion resistance
Improving machining properties
Providing high strength at elevated temperatures
Raising the elastic limit
Which is false statement about annealing? Annealing is done to
Relieve stresses
Harden steel slightly
Improve machining characteristic
Soften material
German silver contains
1% silver
2% silver
5% silver
No silver
Neutral solution is one which has pH value
Greater than 7
Less than 7
Equal to 7
pH value has nothing to do with neutral solution
Steel made from phosphate iron is
Brittle
Hard
Ductile
Tough
Maximum percentage of carbon in ferrite is
0.025 %
0.06 %
0.1 %
0.25 %
In high speed steels, manganese is used to tougher the metal and to increase its
Yield point
Critical temperature
Melting point
Hardness
Wrought iron
Is a ductile material
Can be easily forged or welded
Cannot stand sudden and excessive shocks
All of these