Pick out the wrong statement.
Lead can creep under its own weight at room temperature
The electrical conductivity of gold is considerably reduced by alloying additions due to the decrease in electron movement
Recrystallisation temperature decreases with decrease in strain in a cold worked metal
With increase in temperature, the electrical conductivity of intrinsic semi-conductor will increase
Correct Answer :
C. Recrystallisation temperature decreases with decrease in strain in a cold worked metal
Related Questions
According to maximum shear stress failure criterion, yielding in material occurs, when the maximum shear stress is equal to __________ times the yield stress.
0.5
2
√2
√3/2
Routing in production, planning & control is concerned with the
Sequence of operation to be performed
Progress of work performed
Authorisation of work to be performed
Balancing of load on machines
The minimum temperature to which the water can be cooled in a cooling tower is the __________ temperature of air.
Ambient
Dry bulb
Dew point
Wet bulb
A steam pipe is intended to be insulated with two layers of insulating materials of different thermal conductivities. For minimum heat transfer to take place
The better insulation material should be put just next to pipe (i.e., inside)
The better insulating material should be put outside
Either of the insulating material could be put on either side
Steam temperature is considered before deciding as to which insulating material is to be put inside (i.e., just next to the pipe)
The property of material, by which a given amount of energy is absorbed by it, without plastic deformation, is called
Resilience
Toughness
Ductility
Impact strength
The temperature at which the magnetic property of iron disappears (i.e., it becomes non-magnetic) and its electrical conductivity & specific heat also changes, is called the 'Curie point', which is __________ °C.
768
908
1400
1539
__________ cannot increase the fatigue strength of a material.
Grain refining
Grain coarsening
Surface hardening
Shot peening
Eutectic reaction for iron-carbon system occurs at a temperature of __________ °C.
723
959
1147
1493
Atomic __________ is a whole number for an element.
Number
Weight
Radius
None of these
Leakage in a cooking gas cylinder is detected by
Radio-isotopes
Pouring soap solution on the surface and locating the gas bubbles
Halide torch
Pungent smell of mercaptans present in the gas
In the formation of cermets, the ratio of ceramic material to metallic material is usually 80:20. Which of the following is a cermet?
Zirconia
Alumina
Bakelite
Tungsten carbide
__________ of test specimens is not involved in any hardness testing method.
Fracture
Indentation
Wear
Scratch
__________ joint is mostly used for joining pipes carrying water at low pressure.
Nipple
Socket
Union
Bell and spigot
Normalising of an object does not
Refine coarse grain structure obtained during hot working
Improve ductility
Improve yield strength
Improve mechanical properties
In extrusion of metals, which of the following statement is true?
Speed of the extruded material is same as that of ram speed
Redundant work is a function of the die angle
Relative motion between the billet surface and the container wall is always present
Hollow ram is used for indirect extrusion
Which of the following material handling equipments is not suitable for moving materials in varying paths?
Hand trolley
Belt conveyor
Crane
Truck
Which of the following is a commonly used manometric liquid for low pressure range?
Ethyl alcohol
Carbon tetrachloride
Glycerol
Ethylene glycol
Consider an ideal solution of components A and B. The entropy of mixing per mole of an alloy containing 50% B is
R ln 2
-R ln 2
3 R ln 2
-3R ln 2
Basicity 
of the slag in Indian blast furnace is in the range of
0.7-1.0
1.1-1.4
1.5 - 1.8
2.0 - 2.5
Which of the following is an acidic constituent of B.F. slag?
FeO
MgO
CaO
Damage to metal surface by mechanical action is called
Pitting
Corrosion
Erosion
None of these
The 'laughing gas' is
Nitrous oxide
Nitric oxide
Nitrogen trioxide
Nitrogen pentoxide
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 diffusion co-efficient of Ni in Cu at 1000 K is 1.93 × 10-16 m2S-1 and it is 1.94 × 10-14 m2S- 1 at 1200 K. The activation energy (in k. J.mole-1) for the diffusion of Ni in Cu is
130
180
230
250
Unit of surface tension in S.I. unit is
Watt/m
Joule/
Newton/
Joule/m
__________ can replace tungsten in high speed steel.
Chromium
Vanadium
Cobalt
Molybdenum
Which of the following has the highest modulus of elasticity (about 7 × 106 kg/cm2)?
High speed steel
Stainless steel
Tungsten carbide
Superalloys
In a furnace with heating element temperature at 1700°C, the dominant mechanism of heat transfer will be
Conduction
Radiation
Natural convection
Forced convection
Identify the correct statement with reference to the extractive metallurgy of aluminium.
The electrolyte consists of molten Na3AlF6 with approximately 1 to 8% Al2O3
Approximately 80% of the aluminium deposited on the cathode comes from cryolite
Sodium is deposited along with aluminium, but is immediately vaporised
Anode effect sets in when the cryolite concentration goes below 40%.
Working of linear variable differential transducer (LVDT) is based on the principle of variable
Capacitance
Resistance
Mutual inductance
None of these