Which of the following metals cannot be hot worked at room temperature?
Zinc
Nickel
Lead
Tin
Correct Answer :
B. Nickel
Related Questions
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
Which of the following is an example of cathodic protection of metals against corrosion?
Painted steel
Galvanised iron
Case hardened steel
Lead lined reactor
Hot working of lead is carried out at
75°C
373°K
150°C
Room temperature
The refractory brick which has good thermal shock resistance at high temperature but cracks on cooling below 400°C is
Magnesite
Chrome
Silica
Fireclay
The mechanism which changes the value of manipulated variable in response to the output signal from the control unit is called the
Final control element
On-off control
Floating control action
None of these
Basic open hearth furnace (BOF) is not used for producing __________ steel.
Killed
Rimming
High alloy
None of these
Titanium is added to molten aluminium alloys before casting for the purpose of
Grain refinement
Increasing corrosion resistance
Reducing porosity
Improving fluidity
__________ of grey cast iron produces white cast iron.
Tempering
Rapid heating
Rapid cooling
Slow cooling
In a counter flow heat exchanger, hot fluid enters at 170°C & leaves at 150°C, while the cold fluid enters at 50°C & leaves at 70°C. The arithmetic mean temperature difference in this case is __________ °C.
20
60
120
∞
The thermodynamic law, 
= constant, is not followed by the
Free expansion of an ideal gas
Adiabatic expansion of steam in turbine
Adiabatic compression of air
Ideal compression of air
Metalloids
Are good conductor of heat & electricity
Act as electron donors with metals & as electron acceptor with non-metals
Are not necessarily solids at room temperature
Are compounds that exhibit both metallic & non-metallic properties to some extent and are exemplified by elements like germanium, silicon & boron
Consumable electrodes are used in the __________ welding.
Gas
Arc
Thermit
Resistance
In TIG welding, thoriated tungsten electrodes are used, because it
Has higher current carrying capacity
Has better electron emissivity
Is stronger than ordinary tungsten
Is easy to prepare
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
Powder metallurgy technique is used in the production of __________ tools.
Tungsten carbide
High carbon steel
High speed steel
Drilling
A common disinfectant used in village wells for disinfection of water is
Free chlorine
Bromine
Iodine
Potassium permanganate
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
Though tin occurs lower than iron in the electrochemical series, yet it is coated on steel for corrosion protection, because of its
Lower cost
Abundant availability
Resistance to vegetable acids as the tin plate are commercially used in 'canning' industry
None of these
__________ is used as a material of construction for the blade of power saw.
Wrought iron
Stainless steel
Mild steel
High speed steel
Which one is neutral in character?
N2O4
N2O
N2O5
N2O3
What is the percentage of chromium in 18-4-1 high speed steel?
1
4
18
23
As per international norms, the maximum permissible value of noise level in the industrial environment is __________ decibels as measured at a distance of 1.5 metres from the source of noise.
110
85
60
45
An example of unsteady non uniform flow is the flow of liquid under pressure through a
Tapering pipe at constant flow rate
Tapering pipe at either decreasing or increasing flow rate
Long pipeline of constant diameter
None of these
Tempering of a material does not improve its
Machinability
Toughness
Internal stress level
Softness
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
High endurance limit of carburised machine parts is because of the fact that carburisation
Suppresses any stress concentration produced in the parts
Enhances the yield point of the material
Introduces a compressive layer on the surface
Produces a better surface finish
Which of the following is the largest quantum of pressure?
1 kg/cm2
1 bar
1 atmosphere
1 kilo Pascal
The 'laughing gas' is
Nitrous oxide
Nitric oxide
Nitrogen trioxide
Nitrogen pentoxide
Copper deposits are found in India at the following location:
Kudremukh
Kolar
Khetri
Ramagundam
Main constituent of bone ash is
Ammonium phosphate
Calcium phosphate
Animal charcoal
Ammonium sulphate