Pick out the correct statement.
Materials exhibiting high elasticity obey Hooke's law
The elastic behaviour of rubber under compression is the same as its behaviour under tension
The damping capacity of a material is due to its plastic deformation
The stress required to cause plastic flow in polycrystalline material is higher as compared to monocrystalline materials due to the presence of grains of different orientations
Correct Answer :
B. The elastic behaviour of rubber under compression is the same as its behaviour under tension
Related Questions
Silicon in steel
Makes it usable in almost all magnetic circuits where alternating current is used
Increases its electrical resistivity and decreases the hysteresis loss
Is present upto 5% & 4% respectively when used in transformers & motor armatures
All 'a', 'b' & 'c'
In an eutectic system, two elements are completely
Soluble in solid state
Insoluble in liquid state
Insoluble in both solid & liquid state
Soluble in liquid state
Even though heat transfer co-efficient in boiling liquids is large, use of fins is advantageous, when the entire surface is exposed to __________ boiling.
Film
Nucleate
Transition
All modes of
The phenomenon occurring during explosion of a hydrogen bomb is
Nuclear fission
Nuclear fusion
A combination of both nuclear fission & fusion
None of these
Tip of the match stick contains a mixture of
K + S
K + S + K2Cr2O7
S + K2Cr2O7 + White P
None of these
The concentration of (H+) ions is 4 x 10-5 in a solution. Then pH of the solution will be (Given log 4 = 0.6)
4.4
5.6
8.4
2.4
Increase in temperature, in general results in the
Decrease in the viscosities of both liquids & gases
Increase in the viscosities of both liquids & gases
Increase in the viscosity of liquids and decrease in that of gases
Decrease in the viscosity of liquids and increase in that of gases
Electrolytic reduction cell used for conversion of calcined Al2O3 to Al is a carbon lined furnace operating at 800-900 °C. The purpose of electric current supplied to the furnace is to
Achieve very high purity of aluminium (99.9%)
Keep the electrolyte in liquid condition by the generation of heat
Electrolytically dissociate alumina
Both (B) & (C)
'Dikes' are low height walls made around the storage vessels meant for storing hazardous & inflammable material (e.g., petroleum products). Volume of dikes is equal to (where, V = volume of the storage vessel)
V
V/2
2V
3V
Transformer cores are normally made from
Soft ferrites
High purity iron
Grain oriented Fe-Si alloy
Al-Ni-Co alloy
'Ice point' is designated on Fahrenheit temperature scale by
0°
32°
62°
212°
Energy of the sun arises mainly from __________ reactions.
Fusion
Fission
Combustion
None of these
Fibre glass is a composite material of
Glass fibre in a polymer matrix
Glass fibre in a metallic matrix
Polymer fibre in a glassy matrix
Both 'b' & 'c'
The taper provided on pattern for its easy & clean withdrawal from the mould is termed as the __________ allowance.
Casting
Pattern
Draft
Distortion
Catalyst used in the 'catalytic converter' employed in automobile exhaust line for complete combustion/oxidation of carbon monoxide, nitrogen oxides and hydrocarbons is
Alumina
Platinum
Vanadium pentoxide
Iron oxide
Basic open hearth furnace (BOF) is not used for producing __________ steel.
Killed
Rimming
High alloy
None of these
Strain hardening effect in metals subjected to cold working is due to the __________ mechanism.
Slip
Fracture
Winning
Dislocation
X-rays are
Positively charged
Negatively charged
Neutral
Of higher wavelength than visible light
The heat of neutralisation remains constant, when there is a reaction between dilute solutions of strong
Base and strong acid
Base and weak acid
Acid and weak base
None of these
Brittleness induced due to the presence of sulphur in steel can be reduced by adding
Manganese
Magnesium
Vanadium
Copper
Drills are usually made of
Cermets
High speed steel
Alloy steel
Tungsten carbide
__________ number determines whether the fluid flow in an open channel is supercritical, critical or sub-critical.
Mach
Reynolds
Froude
Weber
The only suitable method for hardening the low carbon steel is case hardening. Which of the following is a case hardening process?
Cyaniding
Sherardizing
Spheroidising
None of these
The order of a chemical reaction
Can be determined only experimentally
Can be determined from the stoichiometry of the reaction
Cannot be zero
Can be fractional
Compressed dry air is used as the cutting fluid, while machining
Steel
Cast iron
Aluminium
None of these
Larger length & diameter water pipes are made by
Electrical resistance welding
Die casting
Semi-centrifugal casting
Continuous casting
Pick out the wrong statement.
For a pressure vessel to be classified as 'thin vessel', the ratio of wall thickness to mean radius is less than 0.1
For calculating forces and efficiency of riveted joint, either rivet diameter or rivet hole diameter is used in case of pressure vessel and in structural work
Longitudinal joint is normally made butt joint to maintain the circularity of the vessel
Maximum diameter of the opening provided in a pressure vessel, which does not require any compensation is 200 mm
The starting of a car takes time in winter, because the
Octane number of fuel is decreased
Fuel supply for ignition is not sufficient
Vaporisation of the fuel is decreased
Pour point of fuel decreases
Pick out the wrong statement.
The equivalent stiffness of two springs (of equal stiffness 'S') in series is S/2 while in parallel is 2S
For a helical spring, deflection is proportional to D3 (D = mean coil diameter) or d4 (d = wire diameter)
Crushing load or columns is less than the buckling load
Modulus of resilience is proportional to (stress at elastic limit)2
Nitriding of a steel part does not increase its
Grain size
Fatigue limit
Surface hardness
Wear resistance