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
Description : Low thermal conductivity of heat insulating materials is due to its (A) Dense structure (B) High proportion of air space (C) High specific heat (D) None of these
Last Answer : (B) High proportion of air space
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 : 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)
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 : 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 : ick out the undesirable property for a good refrigerant. (A) High thermal conductivity (B) Low freezing point (C) Large latent heat of vaporisation (D) High viscosity
Last Answer : (D) High viscosity
Description : Which of the following is an undesirable property of slag produced during the Pyrometallurgical method of metal extraction from its ore? (A) High fusibility & fluidity (B) High thermal conductivity (C) Low density (D) High chemical activity
Last Answer : B) High thermal conductivity
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 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 : (3) reflection of light due to the presence of free electrons Explanation: Lustre (or luster) is the way light interacts with the surface of a crystal, rock, or mineral. The word ... conductivity, and high density. Typically they are malleable and ductile, deforming -under stress without cleaving.
Last Answer : Cloud is a colloidal dispersion of – (1) Air in a dispersion medium of water (2) Fog in a dispersion medium of water (3) Mist in a dispersion medium of air (4) Water drops in a dispersion medium of air
Description : Refractory metals are known for which of the following properties: w) lack of chemical reactivity x) low density y) high melting point z) high thermal conductivity
Last Answer : ANSWER: Y -- HIGH MELTING POINT
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
Last Answer : (B) Increases
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 : 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
Last Answer : (A) Diffusivity of solute increases
Description : During agitation of liquids, power consumption during laminar flow is not proportional to the (A) Density of the liquid (B) Viscosity of the liquid (C) Cube of impeller diameters (D) Square of rotational speed
Last Answer : (A) Density of the liquid
Description : __________ are mixed using ribbon blenders. (A) Lumpy solids and low viscosity liquids (B) Dry powders (C) High viscosity liquids (D) Thick pastes
Last Answer : (B) Dry powders
Description : Paddle agitator (A) Is suitable for mixing low viscosity liquids (B) Produces axial flow (C) Moves at very high speed (D) None of these
Last Answer : (A) Is suitable for mixing low viscosity liquids
Description : Propellers are (A) Axial flow mixers (B) Low speed impeller (C) Used for mixing liquids of high viscosity (D) Radial flow mixers
Last Answer : (A) Axial flow mixers
Description : Pick out the wrong statement. (A) The X-rays cannot be deflected by electric field unlike cathode rays (B) The intensity of X-rays can be measured by ionisation current produced due to the ... the anode-cathode voltage (D) Crystal structure of a material can be studied by an electron microscope
Last Answer : (C) The quality of X-rays can be controlled by varying the anode-cathode voltage
Description : Spherical shape of mercury droplets is due to its (A) High viscosity (B) Low surface tension (C) High density (D) High surface tension
Last Answer : Option D
Description : Brass tubes are used in the manufacture of tubes of evaporators used in sugar and salt industries, mainly because of its (A) High co-efficient of thermal expansion (B) Low thermal conductivity (C) High corrosion resistance (D) All (A), (B) and (C)
Last Answer : (C) High corrosion resistance
Description : Which of the following properties is not true for an alkali metal? (a) Low electronegativity (b) Low ionisation energy (c) Low atomic volume (d) Low density
Last Answer : Ans:(c)
Description : In a furnace, the heat taken by the charge/stock and the heat lost to the furnace structure & flue gases depends on the (A) Rate of firing and emissivity of flame (B) Thermal conductivity of the charge & ... (C) Nature of process; whether batch, continuous or intermittent (D) All (A), (B) and (C)
Last Answer : (D) All (A), (B) and (C)
Description : Coke oven regenerators are made of __________ bricks. (A) Fire clay (B) Silica (C) Low thermal conductivity (D) High electrical conductivity
Last Answer : (A) Fire clay
Description : A bearing metal should not have (A) Enough plasticity (B) Low thermal conductivity (C) Low co-efficient of friction (D) High toughness
Last Answer : (B) Low thermal conductivity
Description : Thickness of stock does not affect the fuel economy of furnaces, if thematerial to be heated is of (A) Low emissivity (B) High thermal conductivity (C) Both (A) and (B) (D) Neither (A) nor (B)
Last Answer : (C) Both (A) and (B)
Description : Dielectric (A) Is an electrical insulating material (B) Of low resistivity is preferred (C) Should have high thermal conductivity (D) Need not defy the corrosive action of chemicals
Last Answer : (A) Is an electrical insulating material
Description : ideal material for making cooking vessels should have (A) High heat capacity (B) Low heat capacity (C) High thermal conductivity (D) Both (B) and (C)
Description : Which of the following physical properties is TRUE of most dense ceramic materials? w) high tensile strength x) good ductility y) high compressive strength z) high electrical conductivity
Last Answer : ANSWER: Y -- HIGH COMPRESSIVE STRENGTH
Description : On a cold day when the room temperature is 15°C, the metallic cap of a pen becomes much colder than its plastic body, though both are at the same temperature of 15°C, because - (1) metals ... metals (3) metals are good conductors of heat (4) plastics have a higher thermal conductivity than metals
Last Answer : (3) metals are good conductors of heat Explanation: On a chilly day, the room temperature is lower than our body temperature. Since metals have a higher coefficient of thermal conductivity than plastic, they ... from our fingers will flow to the metal cap much more quickly than to the plastic body.
Description : On a cold day when the room temperature is 15°C, the metallic cap of a pen becomes much colder than its plastic body, though both are at the same temperature of 15°C, because : (1) metals ... metals (3) metals are good conductors of heat (4) plastics have a higher thermal conductivity than metals
Last Answer : metals are good conductors of heat
Description : Choose the wrong statement (A) Viscosity of a fluid is that property which determines the amount of its resistance to a shearing force (B) Viscosity is due primarily to interaction between fluid molecules (C) Viscosity of liquids decreases with increase in temperature (D) Viscosity of liquid
Last Answer : Answer: Option D
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 : Liquids having low viscosity are called?
Last Answer : Mobile liquids eg : Water; Kerosene; Alcohol; Petro -
Description : Of the following liquids, which is most dense? w) water x) gasoline y) acetone z) chloroform
Last Answer : ANSWER: Z -- CHLOROFORM
Description : Vacuum filter is most suitable for the (A) Removal of fines from liquid (B) Liquids having high vapour pressure (C) Liquids of very high viscosity (D) None of these
Last Answer : (D) None of these
Description : Which of the following agitators having a large blade area, rotating at slow speed is used for mixing high viscosity liquids (> 50000 centipoise)? (A) Propeller (B) Helical screw (C) Flat blade turbine (D) Curved blade turbine
Last Answer : (B) Helical screw
Description : Solvent extraction is the terminology applied to the liquid-liquid extraction, which is preferred for the separation of the components of liquids, when (A) Extracting solvent is cheaply & abundantly available ... very high (D) One of the liquid components has very high affinity towards the solvent
Last Answer : (D) One of the liquid components has very high affinity towards the solvent
Description : Forced circulation evaporators are normally used for concentrating liquids having (A) Scaling characteristics (B) High viscosity (C) Both (A) & (B) (D) Neither (A) nor (B)
Last Answer : (C) Both (A) & (B)
Description : Which of the following is an undesirable property of a manometricliquid? (A) Non-sticky & non-corrosive nature (B) High vapour pressure (C) Low viscosity & surface tension (D) Low co-efficient of thermal expansion
Last Answer : (B) High vapour pressure
Description : Plate towers are preferred to packed towers, when large temperature changes are involved, because of the reason that the (A) Packing may be crushed due to thermal expansion/contraction of the ... C) Viscosity variation of the fluids may cause channelling/flooding (D) None of these
Last Answer : (A) Packing may be crushed due to thermal expansion/contraction of the components of the equipments
Description : Which solid material has a high heat capacity but low thermal conductivity?
Last Answer : https://en.wikipedia.org/wiki/Thermal_barrier_coating
Description : Which of the following properties is not necessarily desirable in the material for transformer core? A. Mechanical strength B. Low hysteresis loss C. High thermal conductivity D. High permeability
Last Answer : C) high thermal conductivity
Description : How do you list liquids in order from least dense to most dense?
Last Answer : First, you need to look up, calculate, or measure the density ofeach liquid. Then you can make a list, and sort the list.BothMS-Word and Excel have options for sorting lists; or if the list isrelatively short, you can do it manually.
Description : Sodium vapour lamps glow with yellow colour. This is due to - (1) sublimation of sodium to emit yellow colour (2) the emission of excess energy absorbed by sodium atoms, in the yellow region of the ... (3) the low ionisation energy of sodium (4) its ability to absorb all other colours except yellow
Last Answer : (2) the emission of excess energy absorbed by sodium atoms, in the yellow region of the spectrum Explanation: Sodium Vapour Lamps glow with yellow colour due to the emission of excess energy absorbed by sodium atoms, in the yellow region of the spectrum.
Description : Sodium vapour lamps glow with yellow colour. This is due to (1) sublimation of sodium to emit yellow colour (2) the emission of excess energy absorbed by sodium atoms, in the yellow region of the ... (3) the low ionisation energy of sodium (4) its ability to absorb all other colours except yellow
Last Answer : the emission of excess energy absorbed by sodium atoms, in the yellow region of the spectrum
Description : Copper has very low (A) Malleability (B) Ductility (C) Tensile strength (D) Thermal & electrical conductivity
Last Answer : (C) Tensile strength
Description : Coke oven walls are lined with __________ bricks. (A) Silica (B) Tar-dolomite (C) Low thermal conductivity (D) Fire clay
Last Answer : (A) Silica
Description : Finned tube heat exchangers (A) Give larger area per tube (B) Use metal fins of low thermal conductivity (C) Facilitate very large temperature drop through tube wall (D) Are used for smaller heat load
Last Answer : (A) Give larger area per tube