With increase in temperature, the rate of leaching increases, because
the
(A) Diffusivity of solute increases
(B) Viscosity of solvent decreases
(C) Thermal conductivity of solute increases
(D) None of these
Description : With increase in temperature, the leaching rate increases because of the (A) Increased diffusivity (B) Decreased viscosity of liquid (C) Both (A) and (B) (D) Neither (A) nor (B)
Last Answer : (C) Both (A) and (B)
Description : With increase in temperature, the leaching rate increases due to (A) Decreased liquid viscosity (B) Increased diffusivity (C) Both (A) and (B) (D) Neither (A) nor (B)
Description : Rate of leaching increases with increasing (A) Temperature (B) Viscosity of solvent (C) Pressure (D) Size of the solid
Last Answer : (A) Temperature
Description : 1. __________ of air does not increase with increase in temperature. (A) Density (B) Thermal diffusivity (C) Viscosity (D) Thermal conductivi
Last Answer : Option A
Description : With increase in temperature, the thermal conductivity of steel (A) Increases (B) Decreases (C) Remains unchanged (D) Increases exponentially
Last Answer : (B) Decreases
Description : For gases, the thermal conductivity increases with temperature rise. For liquids, with increase in concentration, its thermal conductivity generally (A) Decreases (B) Increases (C) Remains unchanged (D) Increases exponentially
Last Answer : (A) Decreases
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
Description : With increase in temperature, the thermal conductivity of fresh lubricating oil (A) Increases (B) Decreases (C) Remains unchanged (D) May increase or decrease; depends on its composition
Description : With increase in temperature, the thermal conductivity of most liquids (A) Increases (B) Decreases (C) Remain same (D) First increases upto a certain temperature and then becomes constant
Last Answer : (C) Remain same
Description : With increase in temperature, the thermal conductivity of a gas (A) Increases (B) Decreases (C) Remain same (D) May increase or decrease depending on the type of gas
Last Answer : (A) Increases
Description : Thermal conductivity of a gas at low density, __________ with increase in temperature. (A) Decreases (B) Increases (C) Remains unchanged (D) May increase or decrease; depends on the gas
Description : With increase in temperature, the rate of extraction in leaching (solidliquid extraction system). (A) Increases (B) Decreases (C) Remain unaffected (D) Increases Linearly
Description : Heat transfer rate per unit area is called (A) Thermal conductivity (B) Heat flux (C) Heat transfer co-efficient (D) Thermal diffusivity
Last Answer : (B) Heat flux
Description : With increase in porosity, the thermal conductivity of a solid substance (A) Increases (B) Decreases (C) Remains unchanged (D) May increase or decrease; depends on the solid
Description : A bimetallic strip commonly found in home furnace thermostats works because of the difference in this property of the two metals. Is it: w) thermal shock x) thermal conductivity y) thermal expansion z) thermal diffusivity
Last Answer : ANSWER: Y -- THERMAL EXPANSION
Description : Diffusion co-efficient generally depends upon the temperature, pressure & the nature of the components of the system. Its dimension is not the same as that of the (A) Mass transfer co-efficient (B) Thermal diffusivity (C) Kinematic viscosity (D) Volumetric diffusivity
Last Answer : (A) Mass transfer co-efficient
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
Description : Molecular diffusivity of a liquid (A) Increases with temperature (B) Decreases with temperature (C) May increase or decrease with temperature (D) Is independent of temperature
Last Answer : (A) Increases with temperature
Description : Heat transfer occurs by natural convection because change in temperature causes difference in (A) Viscosity (B) Density (C) Thermal conductivity (D) Heat capacity
Last Answer : (B) Density
Description : Thermal diffusivity of a material (A) Has the unit m2 /sec (B) Is defined as K/ρ . Cp (C) Is the ratio of thermal conductivity to thermal capacity (D) All (A), (B) and (C)
Last Answer : (D) All (A), (B) and (C)
Description : In Fourier's law, the proportionality constant is called the (A) Heat transfer co-efficient (B) Thermal diffusivity (C) Thermal conductivity (D) Stefan-Boltzmann constant
Last Answer : (C) Thermal conductivity
Description : Thermal diffusivity of a substance is proportional to (where, k = Thermal conductivity) (A) 1/k (B) k (C) k2 (D) 1/k2
Last Answer : (B) k
Description : Pick out the wrong statement. (A) Bubble size increases with the dynamic viscosity of the liquid in case of nucleate pool boiling (B) Thermal conductivity of a dry material is more than ... in kg/hr in an evaporator (D) Vaporisation of organic substances in evaporator mostly causes foam formation
Last Answer : (B) Thermal conductivity of a dry material is more than that of the damp material
Description : Separation of the isotopes of helium for scientific investigations is done by (A) Reverse osmosis (B) Thermal diffusion (C) Leaching (D) Solvent extraction
Last Answer : (B) Thermal diffusion
Description : Which of the following has the same dimension as mass diffusivity? (A) Momentum flux (B) Kinematic viscosity (C) Thermal diffusivity (D) Both (B) and (C)
Last Answer : (D) Both (B) and (C)
Description : The ratio of kinematic viscosity to thermal diffusivity is called the __________ number. (A) Peclet (B) Prandtl (C) Stanton (D) Nusselt
Last Answer : (B) Prandtl
Description : With increase in gas rate, the number of transfer units, NtoG, for a fixed degree of absorption by a fixed amount of solvent (A) Increases (B) Decreases (C) Decreases linearly (D) Remains unaffected
Description : With increase in solvent rate, the number of transfer units, NtoG, for a fixed degree of absorption from a fixed amount of gas (A) Increases (B) Decreases (C) Decreases linearly (D) Remain unaffected
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
Description : On addition of solute in the solvent, the __________ of the solution decreases. (A) Boiling point (B) Freezing point (C) Vapour pressure (D) Both (B) and (C)
Description : At a given temperature, the volume of a gas dissolved in a solvent __________ with increase in pressure. (A) Increases (B) Decreases (C) Remains unchanged (D) May increase or decrease; depends on the gas
Last Answer : C) Remains unchanged
Description : Stage efficiency in a leaching process depends on the (A) Time of contact between the solid and the solution (B) Rate of diffusion of the solute through the solid and into the liquid (C) Both (A) and (B) (D) Vapour pressure of the solution
Description : Heat transfer rate described by Fourier's law will decrease, if the __________ increases. (A) Thermal conductivity (B) Thickness (C) Temperature difference (D) Heat transfer area
Last Answer : (B) Thickness
Description : With increase in temperature, the electrical conductivity of semiconductors (A) Increases (B) Decreases (C) Remain constant (D) Either (A) or (B), depends on the type of semi-conductor
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
Description : With increase in the shear rate, the apparent viscosity of pseudo-plastic fluids (A) Increases (B) Decreases (C) Remain same (D) May increase or decrease; depends on the magnitude of shear rate
Description : The activity co-efficient of the solute in a dilute solution (A) Decreases with the increase of concentration of the solute (B) Increases with the increase of concentration of the solute (C) Remains constant (D) Is unity at infinite dilution
Last Answer : (C) Remains constant
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
Description : Viscosity of a polymer solution or melt (A) Decreases with increase in molecular weight (B) Decreases with increase in temperature (C) Increases with increase in temperature (D) Does not vary with temperature rise
Last Answer : (C) Increases with increase in temperature
Description : With increase in the temperature, viscosity of a liquid (A) Increases (B) Decreases (C) Remain constant (D) May increase or decrease; depends on the liquid
Description : . With increase in temperature, the electrical conductivity of semiconductors (A) Increases (B) Decreases (C) Remain constant (D) Either (A) or (B), depends on the type of semi-conductor
Description : Presence of a non-condensing gas in a condensing vapour (A) Increases the rate of condensation (B) Decreases thermal resistance (C) Is desirable to increase the film co-efficient (D) None of these
Description : The mass transfer co-efficient for a solid sphere of radius 'a' dissolving in a large volume of quiescent liquid, in which ‘D’ is the diffusivity of solute, is (A) D/a (B) D/2a (C) Proportional to √D (D) Dependent on the Reynolds number
Last Answer : (D) Dependent on the Reynolds number
Description : The rate of solid-liquid extraction is limited by the (A) Phase change of the solute as it dissolves in the solvent (B) Diffusion of the solute through the solvent in the pores to the outside of the particle (C) ... contact with the particle to the main bulk of the solution (D) All 'a', 'b' & 'c'
Last Answer : (D) All 'a', 'b' & 'c'
Description : Diffusivity in concentrated solutions differs from that in dilute solutions, because of the changes in (A) Viscosity with concentration (B) Degree of ideality of the solution (C) Both (A) and (B) (D) Neither (A) nor (B)
Description : Power consumption during turbulent flow in agitation tank is proportional to the __________ of the liquid. (A) Viscosity (B) Thermal conductivity (C) Surface tension (D) Density
Last Answer : (D) Density
Description : The type of liquor circulation system to be ' employed in evaporators (viz. natural or forced circulation) is determined mainly by the __________ of the liquid. (A) Viscosity (B) Density (C) Thermal conductivity (D) Corrosive nature
Last Answer : (A) Viscosity
Description : Dittus-Boelter equation cannot be used for molten metals mainly due to its very low (A) Prandtl number (B) Grashoff number (C) Thermal conductivity (D) Viscosity
Last Answer : (A) Prandtl number
Description : Among liquids, water has a comparatively high value of thermal conductivity, due to its (A) Low density (B) High viscosity (C) Partial ionisation (D) Dense structure
Last Answer : (C) Partial ionisation
Description : Boiling point of a solution according to Duhring's rule is a linear function of the __________ of water. (A) Boiling point (at the same pressure) (B) Viscosity (C) Density (D) Thermal conductivity
Last Answer : (A) Boiling point (at the same pressure)