A highly elastic material is deformed least on loading and retains its original form on removal of the load. Which of the following is the most elastic material?
Steel
Glass
Rubber
Brass
Correct Answer :
A. Steel
Related Questions
Unit of viscosity in CGS system is
Silicon crystal can be converted to p-type semiconductor by doping with
Phosphorous
Nitrogen
Carbon
Boron
With increase in temperature, the surface tension of water
Increases
Decreases
Remain constant
Increases linearly
Stainless steel is welded using
Oxy-acetylene flame
Oxy-hydrogen flame
Arc welding
Inert gas arc welding
Normalising does not __________ of a metal.
Improve machinability & tensile strength
Remove internal stresses
Refine the structure
Remove strains caused by cold working
Percentage of differential pressure lost in a Venturimeter with a tapering of 15° may be about
1
10
25
50
Cold working of a material results in increase in hardness, which is termed as the __________ hardening.
Cold
Work
Age
Induction
Out of the following, the lowest packing of atoms exists in __________ crystal lattice structure.
Hexagonal close, packed (hcp)
Face centred cubic (fcc)
Body centred cubic (bcc)
Simple cubic
With increasing carbon percent in steel beyond 0.8%, its ultimate tensile strength (UTS) and __________ is not affected.
Impact strength
Percent elongation
Hardness
Both 'b' & 'c'
Pick out the wrong statement.
Seam welding, projection welding & spot welding are the classification of electrical resistance welding
Electrode tip in spot welding is of copper and the tip diameter should be equal to t (where, t = plate thickness to be welded)
In spot welding, two pieces to be joined are overlapped and placed between two electrodes
Mild steel sheet cannot be spot welded
Wrought iron is not
Ductile & resistant to corrosion/rusting
Weldable easily
Having uniform strength in all directions
Having maximum tensile strength along the lines of slag distribution
To counteract the bad effects of strain hardening on a cold formed part, it must be
Tempered
Normalised
Annealed
Hardened
Gross national product (GNP) means the total value of __________ in a country.
Goods produced
Gold reserve
Earning of the citizens
Taxes paid
The highest stress that a material can withstand for a specified length of time without excessive deformation is called the __________ strength.
Creep
Endurance
Fatigue
None of these
Which of the following properties of a solid is not dependent on crystal imperfection?
Ductility
Semi-conductivity
Melting point
Yield stress
In connection with corrosion of metals, passivation is the process that
Intensifies deterioration
Changes the composition of the metal
Inhibits further deterioration
None of these
Hardening of steel is not possible, unless it is heated __________ critical point.
Above the highest
Above the lowest
Between the first & second
Between the second & third
Identify the false statement
Martensitic steels are less susceptible to pitting corrosion than austenitic steels
Pitting corrosion is usually very localised
Hydrogen embrittlement is facilitated by tensile stress
Stress corrosion cracking is facilitated by tensile stress
A jig is used while __________ a hole.
Boring
Counter boring
Drilling
Enlarging
Induced draft fans provided in large thermal power plant boilers have __________ blades.
Forward curved
Backward curved
Double curved
Radial or straight
Wave length of X-rays is about 1 angstrom; however it cannot pass through a sheet of
Paper
Cloth
Lead
Aluminium
Recrystallisation temperature of steel is __________ °C.
50
300
500
800
Which of the following processes follows the hardening process for reducing the hardening strains & increasing the toughness of the steel part?
Anodising
Tempering
Carburising
Annealing
Boiling point of water gets lowered at high altitudes (e.g., hills), because
Temperature is low
Atmospheric pressure is low
Atmospheric pressure is high
None of these
Transition from laminar to turbulent zone in free convection heat transfer is governed by the critical value of
Grashoff number
Grashoff number & Reynolds number
Reynolds number
Grashoff number & Prandtl number
The capacity of a spring to store energy is called the spring form co-efficient. Stiffness of a spring is measured by the
Ability to absorb shock
Capacity to store energy
Ratio of the wire & coil diameters
Load to produce unit deflection
Which of the following materials does not form adherent oxide film on surface?
Copper
Nickel
Aluminium
Gold & silver
A metal having a Poisson's ratio = 0.3 is elastically deformed under uniaxial tension. If the longitudinal strain = 0.8, then the magnitude of thickness strain is
-0.8
0.8
+0.08
-0.24
Surface tension of a liquid
Is due to intermolecular forces of cohesion
Decreases with rise in temperature
Is responsible for the spherical shape of an isolated liquid drop
All (A), (B) & (C)
An abrupt and sudden fall in the reading of barometer is an indication of the
Storm
Rain
Clear weather
Cold wave