Description : Pick out the wrong statement. (A) Hard glass which is used for making laboratory glass wares is a mixture of sodium borosilicate and aluminium borosilicate (B) Glass is decolorized during its manufacture by ... Na2O . CaO . 6SiO2 (D) Red color is imparted to glass by addition of arsenic oxide
Last Answer : (D) Red color is imparted to glass by addition of arsenic oxide
Description : Superior quality laboratory apparatus is made of the __________ glass having low thermal co-efficient of expansion & high chemical resistance. (A) Flint (B) Soda (C) Pyrex (D) Potash
Last Answer : (C) Pyrex
Description : __________ glass has the lowest co-efficient of thermal expansion and hence is more heat resistant. (A) Pyrex (B) Soda lime (C) Lead (D) High silica
Last Answer : (A) Pyrex
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 : Limestone addition in the blast furnace is done to flux __________ present in the raw materials. (A) SiO2 (B) Al2O3 (C) MnO2 (D) P
Last Answer : Limestone addition in the blast furnace is done to flux __________ present in the raw materials. (A) SiO2 (B) Al2O3 (C) MnO2 (D) P
Description : Addition of stabiliser during PVC manufacture is done to (A) Improve its impact strength (B) Improve its elasticity (C) Reduce the melt viscosity & glass transition temperature (D) Prevent its thermal degradation
Last Answer : (D) Prevent its thermal degradation
Description : The expression, nCv(T2- T1), is for the __________ of an ideal gas. (A) Work done under adiabatic condition (B) Co-efficient of thermal expansion (C) Compressibility (D) None of these
Last Answer : (A) Work done under adiabatic condition
Description : Blue colour is imparted to glass by the addition of (A) FeSO4 (B) PbO (C) CaO (D) NaOH
Last Answer : (C) CaO
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 : Pick out the wrong statement pertaining to the properties of glasses. Glasses generally have (A) High electrical insulation properties (B) Sharp melting points (C) Low co-efficient of thermal expansion (D) Compressive strength much greater than their tensile strengths
Last Answer : (B) Sharp melting points
Description : (1/V) (∂V/∂T)Pis the mathematical expression (A) Joule-Thomson co-efficient (B) Specific heat at constant pressure (Cp) (C) co-efficient of thermal expansion (D) Specific heat at constant volume (CV)
Last Answer : (C) co-efficient of thermal expansion
Description : The expression, nRT ln(P1/P2), is for the __________of an ideal gas. (A) Compressibility (B) Work done under adiabatic condition (C) Work done under isothermal condition (D) Co-efficient of thermal expansion
Last Answer : C) Work done under isothermal condition
Description : Steel rods are normally used for concrete reinforcement because concrete and steel have almost equal (A) Tensile strength (B) Compressive strength (C) Young's modulus (D) Thermal co-efficient of expansion
Last Answer : (D) Thermal co-efficient of expansion
Description : Sudden temperature fluctuation does not affect pyrex glass, because of its (A) Low co-efficient of expansion (B) High co-efficient of expansion (C) High melting point (D) Both (B) and (C)
Last Answer : (A) Low co-efficient of expansion
Description : In case of calcination of limestone, CaCO3 CaO + CO2 , the addition of more of CaO will result in __________ in the concentration of CO2 . (A) No change (B) Increase (C) Decrease (D) Unpredictable from the data
Last Answer : (A) No change
Description : A steel alloy containing 36% nickel is called __________, which has a zero co-efficient of expansion. (A) Austenitic stainless steel (B) Heat resisting steel (C) Invar (D) High speed steel
Last Answer : (C) Invar
Description : Metallic surveying tapes are made of __________ which has a low co efficient of expansion & enough strength. (A) Invar (B) Hastelloy (C) Duralumin (D) Monel metal
Last Answer : (A) Invar
Description : Addition of filter aid to the slurry before filtration is done to __________ of the cake. (A) Increase the porosity (B) Increase the compressibility co-efficient (C) Decrease the porosity (D) Decrease the compressibility co-efficient
Last Answer : (A) Increase the porosity
Description : Which of the following is produced during the following reaction ? `CO(g)+H_(2)overset(575K)underset(ZnO,Cr_(2)O_(3))rarr` ……?
Last Answer : Which of the following is produced during the following reaction ? `CO(g)+H_(2)overset(575K)underset(ZnO,Cr_(2)O_ ... 3)COOH` C. `HCOOH` D. `CH_(3)OH`
Description : For absorbing a sparingly soluble gas in a liquid (A) Gas side mass transfer co-efficient should be increased (B) Liquid side mass transfer co-efficient should be increased (C) Liquid side mass transfer co-efficient should be decreased (D) Mass transfer co-efficient must be kept constant
Last Answer : (B) Liquid side mass transfer co-efficient should be increased
Description : For absorbing a sparingly soluble gas in a liquid, the (A) Gas side co-efficient should be increased (B) Liquid side coefficient should be increased (C) Gas side co-efficient should be decreased (D) Liquid side co-efficient should be decreased
Last Answer : (B) Liquid side coefficient should be increased
Description : Increasing the liquor level in the evaporator results in the (A) Decreased capacity (B) Increase in liquor film co-efficient (C) Decreased effect of hydrostatic head (D) Increased true temperature drop
Last Answer : (A) Decreased capacity
Description : The film co-efficient is decreased due to the presence of non-condensing gases in the vapors. The film co-efficient of superheated vapor as compared to that of saturated vapor is (A) More (B) Less (C) Some (D) Either more or less; depends on the nature of vapor
Last Answer : (C) Some
Description : A coal with high ash content is undesirable, as (A) It is abrasive to the coal pulveriser (i.e. ball mill) and the combustion chamber (B) The ash in molten condition gets absorbed in the pores of the ... and stick to the boiler tubes thereby reducing the heat transfer (D) All (A), (B) and (C)
Last Answer : (D) All (A), (B) and (C)
Description : Extraction of Zn is based on the following thermodynamic reaction. (A)` 2ZnS + 3O_(2) to 2ZnO+ 2SO_(2)` (B) `ZnO + C to Zn + CO" " DeltaG_(f)^(0)` are
Last Answer : Extraction of Zn is based on the following thermodynamic reaction. (A)` 2ZnS + 3O_(2) to 2ZnO+ 2SO_(2)` (B) ... (5) J//"mol"` The value of X a will be
Description : Which of the following is universally employed as the low expansion metal in the bimetallic thermometer, which is an iron-nickel alloy containing 36% nickel and has very low co-efficient of expansion (1/20th of ordinary metals) ? (A) Invar (B) Constantan (C) Chromel (D) Alumel
Description : Out of the following refrigeration cycles, which one has the minimum COP (Co-efficient of performance)? (A) Air cycle (B) Carnot cycle (C) Ordinary vapour compression cycle (D) Vapour compression with a reversible expansion engine
Last Answer : A) Air cycle
Description : The chemical formula of iron pyrites is— (A) FeSO 4 (B) FeS (C) FeS 2 (D) Fe 2 (SO 4 ) 3
Last Answer : (C) FeS 2
Description : Glass is (A) Mainly CaO (B) Subjected to galvanising (C) A super cooled liquid (D) All (A), (B) and (C)
Last Answer : (C) A super cooled liquid
Description : __________ is used as a catalyst in fat splitting. (A) ZnO (B) Ni (C) V2O5 (D) FeO
Last Answer : (A) ZnO
Description : Consider the production of ammonia from methene and air as raw materials. The catalysts used are: (i) __________ for steam reforming of methane and (ii) __________ for ammonia synthesis. (A) (i) - Ni/Al2O3 ; (ii) - Cu - ZnO/ ... (i) - Ni/Al2O3 ; (ii) - Fe/Al2O3 (D) (i) - Fe/Al2O3 ; (ii) - Ni/Al2O3
Last Answer : (C) (i) - Ni/Al2O3 ; (ii) - Fe/Al2O3
Description : Pick out the endothermic reaction out of the following. (A) C+ ½O2 = CO (B) CO + 3H2 = CH4 + H2O (C) CaCO3 = CaO + CO2 (D) CO + ½O2 = CO2
Last Answer : (C) CaCO3 = CaO + CO2
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 : Concrete containing (A) Siliceous aggregates, has higher co-efficient of expansion (B) Igneous aggregates, has intermediate coefficient of expansion (C) Lime stones, has lowest co-efficient of expansion (D) All the above
Last Answer : Answer: Option D
Description : For aluminium, as compared to copper, all the following factors have higher values except (a) specific volume (6) electrical conductivity (c) co-efficient of linear expansion (d) resistance per unit length for same cross-section
Last Answer : (6) electrical conductivity
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 : Heat transfer by natural convection is enhanced in system with (A) High viscosity (B) High co-efficient of thermal expansio
Last Answer : (B) High co-efficient of thermal expansion
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
Last Answer : (D) None of these
Description : The thermal efficiency of a reversible heat engine operating between two given thermal reservoirs is 0.4. The device is used either as a refrigerator or as a heat pump between the same reservoirs. Then the coefficient of performance as a ... )R = 1.5; (COP)HP = 2.5 (D) (COP)R = (COP)HP = 2.5
Last Answer : (C) (COP)R = 1.5; (COP)HP = 2.5
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 : The left face of a one dimensional slab of thickness 0.2 m is maintained at 80°C and the right face is exposed to air at 30°C. The thermal conductivity of the slab is 1.2 W/m.K and the heat transfer co-efficient from the ... temperature of the right face in °C is (A) 77.2 (B) 71.2 (C) 63.8 (D) 48.7
Last Answer : (D) 48.7
Description : . The inner wall of a furnace is at a temperature of 700°C. The composite wall is made of two substances, 10 and 20 cm thick with thermal conductivities of 0.05 and 0.1 W.m-1.°C-1 respectively. The ambient air is at 30°C ... from the outer surface in W.m-2 is (A) 165.4 (B) 167.5 (C) 172.5 (D) 175
Last Answer : (A) 165.4
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 : Walls of a cubical oven are of thickness l, and they are made of material of thermal conductivity k. The temperature inside the oven is 100°C and the inside heat transfer co-efficient is 3k/l'. If the wall temperature ... wall temperature in degree centigrade? (A) 35.5 (B) 43.75 (C) 81.25 (D) 48.25
Last Answer : (C) 81.25
Description : Nusselt number/Biot number varies (A) Inversely with thermal conductivity (B) Directly with heat transfer co-efficient (C) Directly with thermal conductivity (D) Inversely with the dimension of the solid
Last Answer : (A) Inversely with thermal conductivity
Description : What is the critical radius of insulation (cms) for a metallic cylinder, if the convective heat transfer co-efficient with the ambient atmosphere is 5 W/m2. °K? Thermal conductivity of metal and insulation material are 40 and 0.1 W/m.°K respectively. (A) 2 (B) 8 (C) 10 (D) 40
Last Answer : (A) 2
Description : Pick up the correct statement from the following: (A) Plastics have generally low melting point (B) The coefficient of thermal expansion of plastics is about three times than that of steel (C) ... fibre-glass with phenolic resins has absorption coefficient of about 0.67 (D) All the above
Description : .In regard to the glass of quartz particles of filling restorative resin; the microfill resins tend to have, A. A higher coefficient of thermal expansion and a higher crashing strength B. ... and a higher crashing strength D. A lower coefficient of thermal expansion and a lower crashing strength
Last Answer : B. A higher coefficient of thermal expansion and a lower crashing strength
Description : Which raw material is used to impart colour to the glass? a) Al2O3 b) CoO c) CaO d) MgO
Last Answer : b) CoO
Description : Which of the following statements about the reaction given below are correct? MnO2 + 4HCI → MnCl2 +2H20 + Cl2 (i) HCl is oxidized to Cl2 (ii) MnO2 is reduced to MnCl2 (iii) MnCl2 acts as an oxidizing agent (iv) HCl acts ... b) (i), (ii) and (iii) (c) (i) and (ii) only (d) (iii) and (iv) only
Last Answer : Answer: . (c)