Pick out the wrong statement. (A) The emissivity of a surface decreases, if it gets corroded by atmospheric environment (B) The emissivity of a surface increases with increase in surface roughness (C) The emissivity of a polished surface is quite low (D) The emissivity of a non-metallic surface decreases with increase in the temperature

Pick out the wrong statement.
(A) The emissivity of a surface decreases, if it gets corroded by atmospheric
environment
(B) The emissivity of a surface increases with increase in surface roughness
(C) The emissivity of a polished surface is quite low
(D) The emissivity of a non-metallic surface decreases with increase in the
temperature
by

1 Answer

Answer :

(A) The emissivity of a surface decreases, if it gets corroded by atmospheric
environment
by

Related questions

Which is NOT a characteristic of emissivity?  A. It is high with most nonmetals  B. It is directly proportional to temperature  C. It is independent with the surface condition of the material  D. It is low with highly polished metals

Description : Which is NOT a characteristic of emissivity?  A. It is high with most nonmetals  B. It is directly proportional to temperature  C. It is independent with the surface condition of the material  D. It is low with highly polished metals

Last Answer : It is independent with the surface condition of the material

With increase in temperature, the total emissivity of conductors (A) Increases (B) Decreases (C) Remain same (D) Decreases linearly

Description : With increase in temperature, the total emissivity of conductors (A) Increases (B) Decreases (C) Remain same (D) Decreases linearly

Last Answer : (A) Increases

With increase in temperature, the thermal conductivity of non-metallic amorphous solids (A) Decreases (B) Increases (C) Remain constant (D) First decreases upto certain temperature and then increases

Description : With increase in temperature, the thermal conductivity of non-metallic amorphous solids (A) Decreases (B) Increases (C) Remain constant (D) First decreases upto certain temperature and then increases

Last Answer : (B) Increases

Pick out the wrong statement. (A) Cp of monatomic gases such as metallic vapor is about 5 kcal/kg.atom (B) The heat capacity of solid inorganic substance is exactly equal to the heatcapacity of the substance in the molten state(C) There is an increase in entropy, when a spontaneous change occurs in anisolated system(D) At absolute zero temperature, the heat capacity for many pure crystallinesubstances is zero

Description : Pick out the wrong statement. (A) Cp of monatomic gases such as metallic vapor is about 5 kcal/kg.atom (B) The heat capacity of solid inorganic substance is exactly equal to the ... isolated system (D) At absolute zero temperature, the heat capacity for many pure crystalline substances is zero

Last Answer : (C) There is an increase in entropy, when a spontaneous change occurs in an isolated system

Pick out the wrong statement: (A) Greater is the kinematic viscosity of the liquid, greater is the thickness of the boundary layer (B) Blowers develop a maximum pressure of 2 atmospheres (C) Friction losses in pipe fittings are generally expressed in terms of velocity heads (D) Fanning friction factor in case of turbulent flow of liquids in pipe depends upon relative roughness & Reynolds number

Description : Pick out the wrong statement: (A) Greater is the kinematic viscosity of the liquid, greater is the thickness of the boundary layer (B) Blowers develop a maximum pressure of 2 atmospheres ( ... factor in case of turbulent flow of liquids in pipe depends upon relative roughness & Reynolds number

Last Answer : (C) Friction losses in pipe fittings are generally expressed in terms of velocity heads

Pick out the wrong statement. (A) In a static mass of liquid, the pressure at a point is the same for all liquids (B) Pressure decreases exponentially with elevation in an isothermal atmosphere(C) Atmospheric pressure = absolute pressure ‒ gage pressure(D) As per Pascal's law, the pressure at a point in a static or uniformlymoving fluid is equal in all directions

Description : Pick out the wrong statement. (A) In a static mass of liquid, the pressure at a point is the same for all liquids (B) Pressure decreases exponentially with elevation in an isothermal atmosphere (C) ... s law, the pressure at a point in a static or uniformly moving fluid is equal in all directions

Last Answer : (A) In a static mass of liquid, the pressure at a point is the same for all liquids

Pick out the wrong statement pertaining to solvent extraction of oil. Rate of extraction (A) Decreases with decrease of thickness of the flakes(B) Increases with the increasing flake size keeping the flake thicknessconstant(C) Increases considerably with the rise of temperature(D) Decreases as the moisture content of flakes increases

Description : Pick out the wrong statement pertaining to solvent extraction of oil. Rate of extraction (A) Decreases with decrease of thickness of the flakes (B) Increases with the increasing flake size ... considerably with the rise of temperature (D) Decreases as the moisture content of flakes increases

Last Answer : (D) Decreases as the moisture content of flakes increases

Pick out the wrong statement. (A) A refrigeration cycle violates the second law of thermodynamics (B) Refrigeration cycle is normally represented by a temperature vs. entropy plot (C) In a refrigerator, work required decreases as the temperature of the refrigerator and the temperature at which heat is rejected increases (D) One ton of refrigeration is equivalent to the rate of heat absorption equal to 3.53 kW

Description : Pick out the wrong statement. (A) A refrigeration cycle violates the second law of thermodynamics (B) Refrigeration cycle is normally represented by a temperature vs. entropy plot (C) In a refrigerator, ... (D) One ton of refrigeration is equivalent to the rate of heat absorption equal to 3.53 kW

Last Answer : (A) A refrigeration cycle violates the second law of thermodynamics

Pick out the wrong statement (A) The concentric atmosphere layer just above troposphere is called stratosphere, which is rich in ozone (B) Mesosphere is characterised by very low atmospheric pressure and low temperature (C) Troposphere is a dusty zone containing water vapor and clouds (D) The radio waves used in the long distance radio communication are reflected back to earth by stratosphere

Description : Pick out the wrong statement (A) The concentric atmosphere layer just above troposphere is called stratosphere, which is rich in ozone (B) Mesosphere is characterised by very low atmospheric ... radio waves used in the long distance radio communication are reflected back to earth by stratosphere

Last Answer : (D) The radio waves used in the long distance radio communication are reflected back to earth by stratosphere

During ageing of fluid carrying pipes, the (A) Pipe becomes smoother with use (B) Friction factor increases linearly with time (C) Absolute roughness decreases with time (D) Absolute roughness increases linearly with time

Description : During ageing of fluid carrying pipes, the (A) Pipe becomes smoother with use (B) Friction factor increases linearly with time (C) Absolute roughness decreases with time (D) Absolute roughness increases linearly with time

Last Answer : (D) Absolute roughness increases linearly with time

Pick out the wrong statement regarding the solubility characteristics of high polymers. (A) Greater the degree of cross-linking in the polymer, lesser is its solubility (B) Polymers having more aliphatic character are more soluble in aliphatic solvents, while those polymers having more aromatic character are more soluble in aromatic solvents (C) Swelling tendency or solubility of polymers in a particular solvent decreases with increase in molecular weight of the solvent (D) High molecular weight polymers on dissolving gives solution of very low viscosity

Description : Pick out the wrong statement regarding the solubility characteristics of high polymers. (A) Greater the degree of cross-linking in the polymer, lesser is its solubility (B) Polymers having more ... of the solvent (D) High molecular weight polymers on dissolving gives solution of very low viscosity

Last Answer : (D) High molecular weight polymers on dissolving gives solution of very low viscosity

The atmospheric temperature during melting of ice/snow (in the atmosphere) (A) Decreases (B) Increases (C) Remain same (D) May increase or decrease; depends on the altitude where snow melts Answer

Description : The atmospheric temperature during melting of ice/snow (in the atmosphere) (A) Decreases (B) Increases (C) Remain same (D) May increase or decrease; depends on the altitude where snow melts Answer

Last Answer : A) Decreases

Pick out the correct statement pertaining to catalytic cracking. (A) With increase in the reactor pressure, octane number of gasoline decreases (B) With increase in the reactor temperature, gasoline yield decreases for a given conversion (C) Percentage conversion increases with increase in the catalyst to oil ratio (D) All (A), (B) and (C)

Description : Pick out the correct statement pertaining to catalytic cracking. (A) With increase in the reactor pressure, octane number of gasoline decreases (B) With increase in the reactor temperature, gasoline yield decreases for a given ... with increase in the catalyst to oil ratio (D) All (A), (B) and (C)

Last Answer : (D) All (A), (B) and (C)

Pick out the correct statement. (A) Diffusivity decreases with increase in temperature (B) Diffusivity increases with increase in molecular weight (C) Diffusivity increases with the size of the individual molecule (D) None of these

Description : Pick out the correct statement. (A) Diffusivity decreases with increase in temperature (B) Diffusivity increases with increase in molecular weight (C) Diffusivity increases with the size of the individual molecule (D) None of these

Last Answer : (D) None of these

Pick out the wrong statement. (A) The binary diffusivity in liquids is of the order of 10 -5 cm2 /sec (B) Molecular diffusion in solid is much faster than that in liquids (C) Particles movement from higher concentration to lower concentration takes place in diffusion process (D) According to Poiseuille's law, the permeability decreases with increase in temperature for flow of a gas through a given capillary

Description : Pick out the wrong statement. (A) The binary diffusivity in liquids is of the order of 10 -5 cm2 /sec (B) Molecular diffusion in solid is much faster than that in liquids ( ... Poiseuille's law, the permeability decreases with increase in temperature for flow of a gas through a given capillary

Last Answer : (B) Molecular diffusion in solid is much faster than that in liquids

Pick out the wrong statement. (A) Lead can creep under its own weight at room temperature (B) The electrical conductivity of gold is considerably reduced by alloying additions due to the decrease in electron movement (C) Recrystallisation temperature decreases with decrease in strain in a cold worked metal (D) With increase in temperature, the electrical conductivity of intrinsic semi-conductor will increase

Description : Pick out the wrong statement. (A) Lead can creep under its own weight at room temperature (B) The electrical conductivity of gold is considerably reduced by alloying additions due to ... metal (D) With increase in temperature, the electrical conductivity of intrinsic semi-conductor will increase

Last Answer : (C) Recrystallisation temperature decreases with decrease in strain in a cold worked metal

reduction in thermal resistance during heat transfer does not occur in the (A) Convection heat transfer by stirring the fluid and cleaning the heating surface (B) Conduction heat transfer by reduction in the material thickness and increase in the thermal conductivity (C) Radiation heat transfer by increasing the temperature and reducing the emissivity (D) None of these

Description : reduction in thermal resistance during heat transfer does not occur in the (A) Convection heat transfer by stirring the fluid and cleaning the heating surface (B) Conduction heat transfer by ... Radiation heat transfer by increasing the temperature and reducing the emissivity (D) None of these

Last Answer : Option C

Pick out the correct statement. (A) The available energy in an isolated system for all irreversible (real) processes decreases (B) The efficiency of a Carnot engine increases, if the sink temperature is decreased (C) The reversible work for compression in non-flow process under isothermal condition is the change in Helmholtz free energy (D) All (A), (B) and (C)

Description : Pick out the correct statement. (A) The available energy in an isolated system for all irreversible (real) processes decreases (B) The efficiency of a Carnot engine increases, if the sink temperature is decreased ... condition is the change in Helmholtz free energy (D) All (A), (B) and (C)

Last Answer : (D) All (A), (B) and (C)

Pick out the wrong statement. (A) Exit age description function (E) and internal age distribution function (I) are related as, E = -(dI/dθ) (B) Chemisorption studies are useful in the determination of catalyst surface area and pore size distribution (C) A higher temperature favours the reaction of higher activation energy (D) A catalyst increases the potential energy barrier over which the reactants must pass to form products

Description : Pick out the wrong statement. (A) Exit age description function (E) and internal age distribution function (I) are related as, E = -(dI/dθ) (B) Chemisorption studies are useful in the ... energy (D) A catalyst increases the potential energy barrier over which the reactants must pass to form products

Last Answer : (D) A catalyst increases the potential energy barrier over which the reactants must pass to form products

Pick out the wrong statement. (A) In solvent extraction, the distribution co-efficient should be as large as possible for solvent economy (B) With increase in pressure, the solubility of gases in solvent increases at a fixed temperature (C) Decrease in Murphree plate efficiency is an indication of entrainment in distillation column (D) The capacity of a distillation column is maximum at total reflux

Description : Pick out the wrong statement. (A) In solvent extraction, the distribution co-efficient should be as large as possible for solvent economy (B) With increase in pressure, the solubility of ... in distillation column (D) The capacity of a distillation column is maximum at total reflux

Last Answer : (D) The capacity of a distillation column is maximum at total reflux

. Pick out the wrong statement. (A) The eddy viscosity is a function of(B) The eddy viscosity is a fluid property(C) The viscosity of gas increases with increase in temperature(D) The viscosity of a liquid increases with decrease in temperature the type of turbulence involved

Description : . Pick out the wrong statement. (A) The eddy viscosity is a function of the type of turbulence involved (B) The eddy viscosity is a fluid property (C) The viscosity of gas increases with increase in temperature (D) The viscosity of a liquid increases with decrease in temperature

Last Answer : (B) The eddy viscosity is a fluid property

Pick out the wrong statement. (A) The conversion for a gas phase reaction increases with decrease in pressure, if there is an increase in volume accompanying the reaction (B) With increase in temperature, the equilibrium constant increases for an exothermic reaction (C) The equilibrium constant of a reaction depends upon temperature only (D) The conversion for a gas phase reaction increases with increase in pressure, if there is a decrease in volume accompanying the reaction

Description : Pick out the wrong statement. (A) The conversion for a gas phase reaction increases with decrease in pressure, if there is an increase in volume accompanying the reaction (B) With ... phase reaction increases with increase in pressure, if there is a decrease in volume accompanying the reaction

Last Answer : (B) With increase in temperature, the equilibrium constant increases for an exothermic reaction

Pick out the wrong statement. (A) Angle of repose of coal increases with its increasing size (B) Specific gravity of coal increases with its increasing maturity (C) Refractive index and reflectance of coal increases with the increasing rank of coal (D) Specific heat of coal decreases with increases in the volatile matter and decrease in the C/H ratio of coal

Description : Pick out the wrong statement. (A) Angle of repose of coal increases with its increasing size (B) Specific gravity of coal increases with its increasing maturity (C) Refractive index and reflectance of ... of coal decreases with increases in the volatile matter and decrease in the C/H ratio of coal

Last Answer : (D) Specific heat of coal decreases with increases in the volatile matter and decrease in the C/H ratio of coal

Pick out the wrong statement (A) A horizontal line on the humidity chart indicates the temperature changes at constant molal humidity (B) When water is cooled from 80 to 70°C by exposure to the air with a wet bulb temperature of 60°C, then both the approach & the range would be 10°C (C) For unsaturated air-water vapor mixture at atmospheric conditions, the wet bulb temperature & adiabatic cooling lines are the same (D) Relative saturation of unsaturated mixture of water vapor & air cannot be increased by either reducing the mixture temperature or by increasing the total pressure

Description : Pick out the wrong statement (A) A horizontal line on the humidity chart indicates the temperature changes at constant molal humidity (B) When water is cooled from 80 to 70°C by exposure ... & air cannot be increased by either reducing the mixture temperature or by increasing the total pressure

Last Answer : (D) Relative saturation of unsaturated mixture of water vapor & air cannot be increased by either reducing the mixture temperature or by increasing the total pressure

Pick out the wrong statement. (A) Surface tension of a substance vanishes at critical point, as there is no distinction between liquid and vapour phases at its critical point (B) Entropy of a system decreases with the evolution of heat (C) Change of internal energy is negative for exothermic reactions (D) The eccentric factor for all materials is always more than one

Description : Pick out the wrong statement. (A) Surface tension of a substance vanishes at critical point, as there is no distinction between liquid and vapour phases at its critical point (B) Entropy of ... is negative for exothermic reactions (D) The eccentric factor for all materials is always more than one

Last Answer : (D) The eccentric factor for all materials is always more than one

With increase in pressure (above atmospheric pressure), the Cp of a gas (A) Increases (B) Decreases (C) Remains unchanged (D) First decreases and then increases

Description : With increase in pressure (above atmospheric pressure), the Cp of a gas (A) Increases (B) Decreases (C) Remains unchanged (D) First decreases and then increases

Last Answer : (A) Increases

Latent heat of dry steam at atmospheric pressure is 539 Kcal/kg; which __________ with increase in the pressure of steam. (A) Decreases (B) Increases (C) Remain same (D) May increase or decrease

Description : Latent heat of dry steam at atmospheric pressure is 539 Kcal/kg; which __________ with increase in the pressure of steam. (A) Decreases (B) Increases (C) Remain same (D) May increase or decrease

Last Answer : (A) Decreases

Pick out the correct statement. (A) The slope of the stripping line is always less than unity (B) For a given separation in a binary distillation column, with increase in reflux ratio (above the minimum reflux ratio), the fixed cost of the distillation column first increases and then decreases (C) In Ponchon-Savarit method of no. of theoretical plate determination, the stripping and rectifying operating lines are vertical at total reflux (D) Kremser-Brown-Souder's equation is used to calculate the efficiency of a plate tower

Description : Pick out the correct statement. (A) The slope of the stripping line is always less than unity (B) For a given separation in a binary distillation column, with increase in reflux ratio ( ... (D) Kremser-Brown-Souder's equation is used to calculate the efficiency of a plate tower

Last Answer : C) In Ponchon-Savarit method of no. of theoretical plate determination, the stripping and rectifying operating lines are vertical at total reflux

Pick out the correct statement. (A) Oxygen content decreases from lignite to bituminous coal as the coalification increases (B) The less the oxygen content, better is the coal, as it reduces the calorific value (C) With increase in oxygen content, moisture holding capacity of coal increases and the caking power decreases (D) All (A), (B) and (C)

Description : Pick out the correct statement. (A) Oxygen content decreases from lignite to bituminous coal as the coalification increases (B) The less the oxygen content, better is the coal, as it reduces the calorific value (C ... capacity of coal increases and the caking power decreases (D) All (A), (B) and (C)

Last Answer : (D) All (A), (B) and (C)

Pick out the wrong statement. (A) Hammer crushers operate by impact action (B) Standard screens have circular opening (C) With increase in mesh number of screens, their diameter in microns decreases (D) 200 mesh screen has 200 openings per linear cm

Description : Pick out the wrong statement. (A) Hammer crushers operate by impact action (B) Standard screens have circular opening (C) With increase in mesh number of screens, their diameter in microns decreases (D) 200 mesh screen has 200 openings per linear cm

Last Answer : (D) 200 mesh screen has 200 openings per linear cm

Pick out the wrong statement. (A) The shear stress at the pipe (dia = D, length = L) wall in case of laminar flow of Newtonian fluids is (D/4L). ∆p (B) In the equation, T. gc = k. (du/dy) n the value of 'n' for pseudoplastic and Dilatant fluid are < 1 and >1 respectively (C) Shear stress for Newtonian fluid is proportional to the rate of shear in the direction perpendicular to motion (D) With increase in the Mach number >0.6, the drag co-efficient decreases in case of compressible fluids

Description : Pick out the wrong statement. (A) The shear stress at the pipe (dia = D, length = L) wall in case of laminar flow of Newtonian fluids is (D/4L). ∆p (B) In the equation, T. gc = k. ... to motion (D) With increase in the Mach number >0.6, the drag co-efficient decreases in case of compressible fluids

Last Answer : (D) With increase in the Mach number >0.6, the drag co-efficient decreases in case of compressible fluids

Pick out the wrong statement about the machinability of metals. Machinability of a metal (A) Decreases with increase in strain hardening tendencies (B) Decreases with increase in hardness, in general (C) Depend on the composition, microstructure and physical & mechanical

Description : Pick out the wrong statement about the machinability of metals. Machinability of a metal (A) Decreases with increase in strain hardening tendencies (B) Decreases with increase in hardness, in general (C) Depend on the composition, microstructure and physical & mechanical

Last Answer : Option C

Which of the following equations as suggested by Colebrook and White gives the increase in roughness of a new surface (ε0 ) with age/time (t) (where, ε = roughness of the surface after time't'. α = a co-efficient to be experimentally determined)? (A) ε = ε0 + α.t (B) ε = ε0 + α.t 2 (C) ε = ε0 + α.t 3 (D) ε = ε0 + α.t

Description : Which of the following equations as suggested by Colebrook and White gives the increase in roughness of a new surface (ε0 ) with age/time (t) (where, ε = roughness of the surface after time't'. α = a co-efficient to be experimentally determined ... ε = ε0 + α.t 2 (C) ε = ε0 + α.t 3 (D) ε = ε0 + α.t

Last Answer : (A) ε = ε0 + α.t

Indicate the false statement about the resistance of a wire – (1) it depends on material of wire (2) it is directly proportional to the length of wire (3) it is directly proportional to the area of crosssection of wire (4) resistance of metallic wire increases with increase in temperature

Description : Indicate the false statement about the resistance of a wire – (1) it depends on material of wire (2) it is directly proportional to the length of wire (3) it is directly proportional to the area of crosssection of wire (4) resistance of metallic wire increases with increase in temperature

Last Answer : (3) it is directly proportional to the area of cross-section of wire Explanation: The property of conductor due to which it opposes the flow of current through it is called Resistance. It is ... potential difference across its ends to the current flowing through it The SI unit of resistance is ohm.

Indicate the false statement about the resistance of a wire (1) it depends on material of wire (2) it is directly proportional to the length of wire (3) it is directly proportional to the area of cross-section of wire (4) resistance of metallic wire increases with increase in temperature

Description : Indicate the false statement about the resistance of a wire (1) it depends on material of wire (2) it is directly proportional to the length of wire (3) it is directly proportional to the area of cross-section of wire (4) resistance of metallic wire increases with increase in temperature

Last Answer :  it is directly proportional to the area of cross-section of wire

Pick out the wrong statement. (A) Caustic embrittlement of boiler's metallic parts is caused by highconcentration of caustic soda in boiler feed water(B) Cooling and freezing of water kills the bacteria present in it(C) With increasing boiler operating pressure of steam, the maximumallowable concentration of silica in feed water goes on decreasing(D) Dissolved oxygen content in high pressure boiler feed water should benil

Description : Pick out the wrong statement. (A) Caustic embrittlement of boiler's metallic parts is caused by highconcentration of caustic soda in boiler feed water (B) Cooling and freezing of water kills the ... goes on decreasing (D) Dissolved oxygen content in high pressure boiler feed water should be nil

Last Answer : (B) Cooling and freezing of water kills the bacteria present in it

Pick out the wrong statement pertaining to the cooling towers. (A) In case of induced draft cooling tower, the fan is placed at the top of the tower (B) Effectiveness of forced draft cooling tower is reduced by the recirculation of the humid and hot discharged air (C) A natural draft cooling tower is recommended to be used, when the air humidity is low and air temperature is also low (D) Effectiveness of a mechanical draft cooling tower is reduced with increase in air wet-bulb temperature

Description : Pick out the wrong statement pertaining to the cooling towers. (A) In case of induced draft cooling tower, the fan is placed at the top of the tower (B) Effectiveness of ... Effectiveness of a mechanical draft cooling tower is reduced with increase in air wet-bulb temperature

Last Answer : (D) Effectiveness of a mechanical draft cooling tower is reduced with increase in air wet-bulb temperature

Polythene (low or high density) containers are not corroded by (A) Sulphuric acid (10%) at room temperature (B) Nitric acid (95%) at room temperature (C) Sulphur trioxide at 60°C (D) Any of these

Description : Polythene (low or high density) containers are not corroded by (A) Sulphuric acid (10%) at room temperature (B) Nitric acid (95%) at room temperature (C) Sulphur trioxide at 60°C (D) Any of these

Last Answer : (A) Sulphuric acid (10%) at room temperature

Pick out the wrong statement. (A) A particular chemical reaction is more temperature sensitive at low temperatures (B) A very high value of equilibrium constant, K (K >> 1) indicates that the reaction is practically irreversible in nature (C) The intercept of the Arrhenius plot is called the 'activation energy' (D) Non-ideal flow takes place in reactors due to recycling, channeling or by creation of stagnant regions

Description : Pick out the wrong statement. (A) A particular chemical reaction is more temperature sensitive at low temperatures (B) A very high value of equilibrium constant, K (K >> 1) indicates that the ... ) Non-ideal flow takes place in reactors due to recycling, channeling or by creation of stagnant regions

Last Answer : (C) The intercept of the Arrhenius plot is called the 'activation energy

Pick out the wrong statement. (A) Alloys are harder than their component elements (B) Presence of silicon in steel decreases its electrical resistance (C) Karbate is an acid resistant material of construction (D) Nichrome, a steel alloyed with 10% Ni and 20% Cr can be used upto a temperature of 1100°C

Description : Pick out the wrong statement. (A) Alloys are harder than their component elements (B) Presence of silicon in steel decreases its electrical resistance (C) Karbate is an acid resistant material of construction ... , a steel alloyed with 10% Ni and 20% Cr can be used upto a temperature of 1100°C

Last Answer : (B) Presence of silicon in steel decreases its electrical resistance

Pick out the wrong statement. (A) The toughness of a material decreases, when it is heated (B) Crane hooks are normally made of wrought iron (C) Cold working of a metal decreases its fatigue strength (D) The temperature at which new grains are formed in a metal is known as the recrystallisation temperature

Description : Pick out the wrong statement. (A) The toughness of a material decreases, when it is heated (B) Crane hooks are normally made of wrought iron (C) Cold working of a metal decreases its ... (D) The temperature at which new grains are formed in a metal is known as the recrystallisation temperature

Last Answer : (C) Cold working of a metal decreases its fatigue strength

Pick out the wrong statement. (A) With decrease in feed temperature, the number of plates required for binary distillation decreases for a given ‘L/V’ ratio (B) The extraction per unit of total height for a short packed column is more effective than for a tall column, in case of liquid-liquid extraction(C) Natural draft cooling towers are made of ferroconcrete and its cross￾section is wider at the bottom(D) Vander wall adsorption is also called chemisorption

Description : Pick out the wrong statement. (A) With decrease in feed temperature, the number of plates required for binary distillation decreases for a given L/V' ratio (B) The extraction per unit ... and its cross￾section is wider at the bottom (D) Vander wall adsorption is also called chemisorption

Last Answer : (D) Vander wall adsorption is also called chemisorption

The thermal radiative flux from a surface of emissivity = 0.4 is 22.68 kW/m2 . The approximate surface temperature (K) is (Stefan-Boltzmann constant = 5.67 × 10 -8 W/m2 .K4 )(A) 1000(B) 727(C) 800(D) 1200

Description : The thermal radiative flux from a surface of emissivity = 0.4 is 22.68 kW/m2 . The approximate surface temperature (K) is (Stefan-Boltzmann constant = 5.67 × 10 -8 W/m2 .K4 ) (A) 1000 (B) 727 (C) 800 (D) 1200

Last Answer : (A) 1000

The heating capacity of muffle furnace depends on the (A) Surface area & emissivity of the stock (B) Properties of the muffle wall (temperature, area, and emissivity) (C) Both (A) & (B) (D) Neither (A) nor (B)

Description : The heating capacity of muffle furnace depends on the (A) Surface area & emissivity of the stock (B) Properties of the muffle wall (temperature, area, and emissivity) (C) Both (A) & (B) (D) Neither (A) nor (B)

Last Answer : (C) Both (A) & (B)

The heating capacity of continuous reheating furnace depends upon the (A) Hearth area and furnace temperature (B) Emissivity of the stock (C) Ratio of wall surface to stock surface (D) All (A), (B) and (C)

Description : The heating capacity of continuous reheating furnace depends upon the (A) Hearth area and furnace temperature (B) Emissivity of the stock (C) Ratio of wall surface to stock surface (D) All (A), (B) and (C)

Last Answer : (D) All (A), (B) and (C)

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? (A) Emissivity of pipe surface (B) Diameter & length of the pipe (C) Temperature of hot pipe surface & that of air in the room (D) None of thes

Description : 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? (A) Emissivity of pipe surface (B) Diameter & length of the pipe (C) Temperature of hot pipe surface & that of air in the room (D) None of thes

Last Answer : Option D

With increase in temperature, the surface tension of water (A) Increases (B) Decreases (C) Remain constant (D) Increases linearly

Description : With increase in temperature, the surface tension of water (A) Increases (B) Decreases (C) Remain constant (D) Increases linearly

Last Answer : Option B

Silver gets corroded due to ______ in air. (1) Oxygen (2) Hydrogen Sulphide (3) Carbon dioxide (4) Nitrogen

Description : Silver gets corroded due to ______ in air. (1) Oxygen (2) Hydrogen Sulphide (3) Carbon dioxide (4) Nitrogen

Last Answer : (2) Hydrogen Sulphide Explanation: Silver is a fairly stable metal and under normal circumstances does not corrode quickly. However, it is particularly susceptible to the effects of the sulfide ... atmosphere, especially in marine environment, and readily forms a surface tarnish of silver sulphide.

Silver gets corroded due to ___ in air. (1) Oxygen (2) Hydrogen Sulphide (3) Carbon dioxide (4) Nitrogen

Description : Silver gets corroded due to ___ in air. (1) Oxygen (2) Hydrogen Sulphide (3) Carbon dioxide (4) Nitrogen

Last Answer : Hydrogen Sulphide