Consumable electrodes are used in the __________ welding.
Gas
Arc
Thermit
Resistance
Correct Answer :
B. Arc
Related Questions
Tumbling is the process of improving the __________ of the materials/parts.
Surface finish
Fatigue limit
Creep limit
Surface cleanliness
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'
Pick out the wrong statement.
Geothermal energy is a non-conventional source of energy
Mass is converted into energy in both nuclear fission & fusion reaction
Inhalation of mercury vapour is not harmful for human beings
Inhalation of arsenic causes cancer
Thermal efficiency of an internal combustion engine is around __________ percent.
8
35
65
80
Addition of small amount of __________ to grey cast iron is done to produce nodular grey cast iron.
Manganese
Phosphorous
Magnesium
Chromium
Materials having __________ lattice structure are usually the most ductile.
Body centred cubic (bcc)
Hexagonal close packed (hcp)
Face centred cubic (fcc)
None of these
A solution which resists change in its pH value on addition of acid/alkali is called the __________ solution.
Neutral
Ideal
Buffer
Zero pH
In troposphere (the weather domain), the temperature 't' at height 'h' above the sea level in metres is given by (where, temperature at sea level is 15°C and t is in °C.)
t = 15 - 0.0065 h
t = 15 + 0.0065 h
t = 0.0035 h - 15
t = 15 - 0.0035 h
Highest cutting speed is achieved by the __________ tool material.
High speed steel
Carbide
Cast alloy
Plain carbon steel
For separating small pieces of metal from engine oil of a car, the best separating technique is the
Chromatography
Evaporation
Filtration
Fractional distillation
__________ of air does not increase with increase in temperature.
Density
Thermal diffusivity
Viscosity
Thermal conductivity
Chlorine acts as a bleaching agent only in the presence of
Dry air
Pure oxygen
Moisture
Sunlight
Diamagnetic materials
Are magnetised by eddy currents only
Are non-magnetic and cannot be magnetised
Are magnetised in direction opposite to the magnetic field
Can be magnetised in one direction only
The ratio of the shear stress to the principal stress on a principal plane is
0
1
1/2
1/3
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
Steel produced from phosphatic iron is __________ in nature.
Malleable
Ductile
Brittle
Tough
Carbon is present in the form of __________ in grey cast iron.
Spheroids
Nodular aggregates of graphite
Flakes
Cementite
Reynolds number of a fluid flowing in a circular pipe is 10,000. What will be the Reynolds number when the fluid velocity is decreased by 30% & the pipe diameter is increased by 30%?
9,100
13,000
7,000
2,550
__________ property of steel increases by addition of large amount of silicon in it.
Mechanical
Machining
Magnetic
Refractory
What is the range of tempering temperature (°C) for most of the materials?
75-100
200-300
350-450
500-600
X-rays are
Positively charged
Negatively charged
Neutral
Of higher wavelength than visible light
Air-petrol ratio for maximum power generation in spark ignition engine is about
6 : 1
12 : 1
18 : 1
24 : 1
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
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
A common disinfectant used in village wells for disinfection of water is
Free chlorine
Bromine
Iodine
Potassium permanganate
In case of simple harmonic motion, displacement is proportional to the
Velocity
Acceleration
Both (A) & (B)
Neither (A) nor (B)
Calorific value of __________ are almost same.
Lignite & anthracite coal
Lignite & coal gas
Petrol & diesel
Coal gas & natural gas
Cold cracking in the heat affected zone of a high strength steel weld can take place because of the
Retained austenite
Martensite formation
Relatively high sulphur content in the base metal
Sufficient hydrogen present in the welding arc
Breakeven point represents the condition, when the company runs under no profit no loss condition. In break even analysis, total cost comprises of fixed cost
Only
Plus variable cost
Plus overhead cost
Plus selling expenses
Catalyst used in the catalytic converter employed in automobiles to convert CO into CO2 and for complete oxidation of un-burnt hydrocarbons is
Nickel
Cobalt
Vanadium
Platinum