Description : Babbitt metal used for making bearings should have (A) High co-efficient of friction between journal and bearing (B) Ability to retain lubricant on its surface (C) Low co-efficient of friction between journal and bearing (D) Both (B) & (C)
Last Answer : (A) High co-efficient of friction between journal and bearing
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 : 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 : 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 : 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 : 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 : 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 : Which of the following is measure of stiffness? a) Modulus of elasticity b) Modulus of plasticity c) Resilience d) Toughness
Last Answer : a) Modulus of elasticity
Description : Toughness index is defined as the ratio of (A) Plasticity index to consistency index (B) Plasticity index to flow index (C) Liquidity index to flow index (D) Consistency index to liquidity index
Last Answer : (B) Plasticity index to flow index
Description : The plasticity of fine soils may be assessed by means of (A) Dry strength test (B) Toughness test (C) Dilatancy test (D) All of these
Last Answer : Answer: Option D
Description : Brittleness is opposite to (a) Toughness (b) Plasticity (c) Malleability (d) None of these
Last Answer : b) Plasticity
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
Description : Tin base and lead base alloys are used for bearing materials. Tin compared to lead has lower (A) Price (B) Corrosion resistance (C) Thermal conductivity (D) Abundant availability
Last Answer : (D) Abundant availability
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 : 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 : 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 : In a system low friction co-efficient facilitates?
Last Answer : In a system low friction co-efficient facilitates reduced velocity lag error.
Description : A 10 cm dia steam pipe, carrying steam at 180°C, is covered with an insulation (conductivity = 0.6 W/m.°C). It losses heat to the surroundings at 30°C. Assume a heat transfer co-efficient of 0 ... that of the un-insulated steam pipe (D) Less than the steam pipe with 5 cms insulation
Last Answer : (B) Less than that of the un-insulated steam pipe
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 : 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 : 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 : 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 : 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 : 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)
Last Answer : Option D
Description : Incorrect statement for co-efficient of friction could be that A. The coefficient of friction is denoted by the Greek letter µ. B. The coefficient of friction is directly proportional to ... D. The coefficient of friction is inversely proportional to the force pressing the surfaces together
Last Answer : The coefficient of friction is constant even in the conditions of fast slipping and high contact pressure
Description : A metal wire of 0.01 m dia and thermal conductivity 200 W/m.K is exposed to a fluid stream with a convective heat transfer coefficient of 100 W/m2 .K. The Biot number is (A) 5.6 (B) 0.025 (C) 3.5 (D) 0.0035
Last Answer : (B) 0.025
Description : The variation of thermal conductivity of a metal with temperature is often correlated using an expression of the form K = K0 + at, where, K is the thermal conductivity and T is the temperature (in °K). The units of 'a' in SI system will be (A) W/m.k (B) W/m (C) W/m.k
Last Answer : (C) W/m.k
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 : __________ 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 : . Which of the following relationships between co-efficient of friction (μ) between rock & roll and a (half of the angle of nip) of the particle to be crushed is correct? (A) μ > tan α (B) μ ≥ tan α (C) μ > tan 2α (D) μ ≤ tan α
Last Answer : (B) μ ≥ tan α
Description : In case of hydraulically smooth pipe, the resistance to flow depends only on the Reynolds number, whereas for a hydraulically rough pipe, the resistance to flow is governed by the relative roughness. Two pipes are said ... co-efficient for flows at equal Reynold number (D) All (A), (B) & (C)
Last Answer : (C) Friction co-efficient for flows at equal Reynold number
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 : 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 : Satisfactory hydrodynamic film in a journal bearing is formed when (a) Journal speed is low; unit pressure on the bearing is high and viscosity of lubricant used is low [IES-2006] ... journal speed, unit pressure on bearing and lubricant viscosity exists resulting in low coefficient of friction
Last Answer : (c) Journal speed is high; unit pressure on the bearing is high and viscosity of lubricant used is high
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 : 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 : 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 : 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 : 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 : Velocity of liquid hydrocarbon fuels in a pipeline cannot be measured by magnetic flow-meters, because their __________ is very low/small. (A) Thermal conductivity (B) Electrical conductivity (C) Specific gravity
Last Answer : (C) Specific gravity
Description : Which of the following criterion is used for any metal to be used as a cooking material? (1) More specific heat (2) More thermal conductivity (3) Less thermal conductivity (4) Less electrical conductivity
Last Answer : (3) Less thermal conductivity Explanation: A metal to be used as a cooking material should have less thermal conductivity.
Description : Which of the following criterion is used for any metal to be used as a cooking material ? (1) More specific heat (2) More thermal conductivity (3) Less thermal conductivity (4) Less electrical conductivity
Last Answer : Less thermal conductivity
Description : A block of weight 20 kg slides with an initial velocity of 2 m sec down an inclined plane on to a spring of stiffness 10 kg/cm. If the co--efficient of friction is 0.2, angle ? = 30 the ratio of ... be a.More than one b.One c.Less than one d.Depends on the stiffness of spring e.None of the above
Last Answer : a. More than one
Description : A particle moves along a rough plane inclined at 30? to the horizontal. The co-efficient of friction between the particle and the plane is 0.1. Its initial velocity is 15 m/sec. The ratio of the velocity of the particle when it move ... be in the regions a.8 ? 10 b.5 ? 7 c.2 ? 3 d.4 ? 6 e.10 ? 13
Last Answer : b. 5 ? 7