The yield point phenomenon observed in annealed low carbon steel is due to the presence of the following element.
Silicon
Carbon
Phosphorous
Chromium
Correct Answer :
B. Carbon
Related Questions
Pick out the wrong statement about the machinability of metals. Machinability of a metal
Decreases with increase in strain hardening tendencies
Decreases with increase in hardness, in general
Depend on the composition, microstructure and physical & mechanical properties
Decreases with increases in tensile strength & decrease in grain size
The pressure drop per unit length for laminar flow of fluid through a long pipe is proportional to (where, A = cross-sectional area of the pipe & D = Diameter of the pipe)
A
D
1/A
1/A2
Which of the following is used to produce draught in the locomotive boilers?
Chimney
Induced draught fan
Forced draught fan
Steam jet arrangement
Which of the following rays has the least wavelength?
Ultraviolet rays
Infrared rays
Cosmic rays
X-rays
With increase in steam pressure, its specific volume decreases
Rapidly first and then slowly
Linearly
Slowly first and then rapidly
Exponentially
Gage pressure within a spherical droplet of a fluid is 'p'. What will be gage pressure within a bubble of the same size & of the same fluid?
p
2 p
0.5 p
0.25 p
Depreciation of machines fails under the indirect expenses head. As per income tax regulations, it is calculated by the __________ method.
Diminishing balance
Sinking fund
Multiple straight line
Sum of the years digit
Filler material used in welding should have __________ as compared to the parent metal to be welded.
Lower melting temperature
Same melting temperature
Same composition
Both 'b' & 'c'
Transformer cores are normally made from
Soft ferrites
High purity iron
Grain oriented Fe-Si alloy
Al-Ni-Co alloy
Young's modulus of a material is the measure of its
Stiffness
Malleability
Creep resistance
Tensile strength
Liquor poisoning generally occurs due to the presence of __________ in it.
Ethyl alcohol
Impurities
Methyl alcohol
Carbonic acid
The size of the tetrahedral void in the closest packing of atoms is __________ that of the octahedral void.
Equal to
Greater than
Less than
Either (A), (B) or (C); depends on the size of atom
Probability of cavitation occuring becomes very high, when the local __________ resulting in water bubbles formation, which on rupture cause cavitation
Pressure falls below the vapour pressure
Pressure becomes very high
Temperature becomes low
All 'a', 'b' & 'c'
Plasma is
A high temperature neutral gas
Nothing but ionised gas
A source of steady and highest controllable pressure
Formed at very low temperature
To counteract the bad effects of strain hardening on a cold formed part, it must be
Tempered
Normalised
Annealed
Hardened
Which of the following is the most suitable abrasive for grinding high tensile strength materials?
Silicon carbide
Corundum
Aluminium oxide
Boron carbide
Gas turbine normally employs a constant __________ cycle.
Pressure
Temperature
Volume
None of these
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
Which of the following parameters is not responsible for the heat loss from a hot steam carrying bare pipe surface located in a room without fans?
Emissivity of pipe surface
Diameter & length of the pipe
Temperature of hot pipe surface & that of air in the room
None of these
What is the pH of distilled water?
0
1
7
14
Circular cross section machine parts which are symmetrical about the axis of rotation are made by hot
Piercing
Spinning
Drawing
Extrusion
Strain hardening effect in metals subjected to cold working is due to the __________ mechanism.
Slip
Fracture
Winning
Dislocation
The bolt is subjected to __________ when the nut is tightened by putting the washer beneath it.
Tension
Shear
Compression
Bending & tension
Pick out the wrong statement.
Complete unity of command exists in a line organisation
Line organisation is net suitable for expansion and growth of an industry
In line and staff organisation, line executes and staff directs
None of these
Larger length & diameter water pipes are made by
Electrical resistance welding
Die casting
Semi-centrifugal casting
Continuous casting
Ultimate strength in tension as compared to that in shear for steel is
Half
One third
One and half times
One fourth
Tempering of a material does not improve its
Machinability
Toughness
Internal stress level
Softness
In fluid flow, and heat and mass transfer, one encounters (i) kinematic velocity (μ), (ii) molecular diffusivity (θ) and thermal diffusivity (α). The units of these quantities are.
μ , α and θ all have units of m/s
μ , α and θ all have units of m2/s
α and θ have units of m2/s, while μ has unit of m/s
α and θ have units of m/s, while μ has unit of m2/s
Tumbling is the process of improving the __________ of the materials/parts.
Surface finish
Fatigue limit
Creep limit
Surface cleanliness
Common salt is produced from sea water in India generally by the __________ method.
Freeze drying
Solar evaporation
Electrolytic
None of these