Description : Which of the following is the most widely used heat insulating material for pipelines carrying steam? (A) Tar dolomite bricks followed by asbestos (B) Fireclay refractory followed by aluminium sheet (C) Cotton followed by aluminium foil (D) 85% magnesia cement and glass wool
Last Answer : (D) 85% magnesia cement and glass wool
Description : Ceramic coating material for furnace refractory, which increases itsemissivity and thus the radiation heat transfer rate in the furnace, comprises of (A) Graphite powder (B) Thoria (C) Zircon powder (D) Beryllium
Last Answer : (C) Zircon powder
Description : Kaolin is a/an (A) Refractory material (B) Synthetic resin (C) Artificial abrasive (D) Blue pigment
Last Answer : (A) Refractory material
Description : Fire clay is __________ refractory material. (A) A basic (B) An acidic (C) A neutral (D) Not a
Last Answer : (B) An acidic
Description : Which of the following is not a dielectric material? (A) Cotton, silk and paper (B) Asbestos, glass, porcelain and mica (C) Rubber and polymeric resins (D) All refractory materials
Last Answer : Option C
Description : Refractory metals are used in construction of furnances because
Last Answer : Refractory metals are used in construction of furnances because A. they can withstand high temperature B. ... is high D. their melting point is low
Description : True statements concerning hypoadrenal shock include which of the following? A. Adrenocortical insufficiency may manifest itself as severe shock refractory to volume and pressor therapy. B. ... test should be performed to help establish the diagnosis of acute adrenocortical insufficiency.
Last Answer : Answer: AD DISCUSSION: Shock due to acute adrenocortical insufficiency is relatively uncommon but must be considered when shock refractory to volume replacement and pressor therapy is present. ... and it is the corticosteroid of choice while the ACTH stimulation test is being performed
Description : In patients of bronchial asthma inhaled corticosteroids achieve the following except (a) Reduce the need for bronchodilator medication (b) Control an attack of refractory asthma (c) Reduce bronchial hyperreactivity (d) Reverse diminished responsiveness to sympathomimetic bronchodilators
Last Answer : Ans: B
Description : Which is the artificial form of aluminium oxide used for making refractory crucibles?
Last Answer : Alundum
Description : Urea autoclave is made of (A) Cast iron (B) Refractory blocks (C) Stainless steel (D) Lead lined steel
Last Answer : (C) Stainless steel
Description : Tank furnace used for melting of glass is made of (A) Mild steel (B) Cast iron (C) Refractory blocks (D) Stainless steel
Last Answer : (C) Refractory blocks
Description : Cermets are __________ materials. (A) Refractory (B) Reinforced (C) Abrasive (D) Fully metallic
Last Answer : (A) Refractory
Description : Rotary driers are generally made of (A) Cast iron (B) Mild steel (C) High silicon iron (14% Si) (D) Tin lined with refractory bricks
Last Answer : (B) Mild steel
Description : Sulphuric acid is mixed with ground phosphate rock (to produce phosphoric acid) in a steel digestor lined with (A) Acidic refractory (B) Rubber (C) Karbate (D) Lead or acid proof bricks
Last Answer : (A) Acidic refractory
Description : Sulphuric acid is mixed with ground phosphate rock (to produce phosphoric acid) in a steel digestor lined with (A) Acidic refractory (B) Rubber (C) Karbate (D) Lead or acid-proof bricks
Last Answer : (D) Lead or acid-proof bricks
Description : Refractory bricks are usually dried in a __________ dryer. (A) Tray (B) Tunnel (C) Conveyor (D) Festoon
Last Answer : (B) Tunnel
Description : Drying of refractory is normally carried out in a __________ dryer. (A) Open pan (B) Tray (C) Rotary vacuum (D) Truck/tunnel
Last Answer : (D) Truck/tunnel
Description : Why refractory metals are used in construction of furnaces ?
Last Answer : Ans. Refractory metals are used in construction of furnaces because they can withstand high temperature.
Description : Absorptivity of a perfect black body is unity. Which of the following has maximum absorptivity? (A) Aluminium foil (B) Refractory bricks (C) Iron plate (D) Coke breeze
Last Answer : (D) Coke breeze
Description : Which of the following has the minimum absorptivity? (A) Aluminium foil (B) Coal dust (C) Refractory bricks (D) Iron plates
Last Answer : (A) Aluminium foil
Description : Compared with myelinated nerve fibres, non-myelinated nerve fibres : a. have a higher threshold for stimulation b. have a longer refractory period c. transmit impulses at a lower frequency d. all above
Last Answer : all above
Description : The time when K+ is moving out of the cell is called a. relative refractory period b. absolute refractory period c. both d. none of them
Last Answer : relative refractory period
Description : Which of the following statements is not correct? (a) An action potential in an axon does not move backward because the segment behind is in a refractory phase. (b) Depolarisation of hair cells ... d) In the knee-jerk reflex, stimulus is the stretching of muscle and response is its contraction.
Last Answer : (c) Rods are very sensitive and contribute to daylight vision.
Description : A refractory wall separating the stock and the source of heat is provided in a (A) Updraft kiln (B) Muffle furnace (C) Continuous furnace (D) None of these
Last Answer : (B) Muffle furnace
Description : Large tonnage of refractory bricks are dried in a (A) Shaft furnace (B) Rotary hearth furnace (C) Tunnel kiln (D) Muffle furnace
Last Answer : (C) Tunnel kiln
Description : Pot furnace which is either regenerative or recuperative, is used in the manufacture of (A) Glass (B) Stainless steel (C) Potteries (D) Refractory bricks
Last Answer : (A) Glass
Description : Heat transfer rate to the charge/stock in a furnace does not depend upon the (A) Type of fuels viz. solid, liquid or gaseous (B) Flue gas temperature (C) Emissivity of refractory walls (D) Initial temperature of the charged stock
Last Answer : (A) Type of fuels viz. solid, liquid or gaseous
Description : Heat transfer rate to the stock/charge in the furnace does not depend upon the (A) Emissivity of the refractory walls (B) Size of the furnace (C) Use of waste heat recovery equipments (D) Thickness of the stock
Last Answer : (C) Use of waste heat recovery equipments
Description : Test specimen for determination of refractoriness under load (RUL) of a refractory is heated in a (A) Furnace employing neutral atmosphere (B) Carbon resistance furnace (C) Reducing atmosphere (D) Furnace employing negative pressure
Last Answer : (B) Carbon resistance furnace
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 : Inhalation of silica dust by human being during hand drilling in mica mining, lead & zinc mining, silica refractory manufacture and in foundries causes (A) Asphyxiation (suffocation) (B) Shortness of breath (C) Tuberculosis (D) All (A), (B) and (C)
Description : Highly porous refractory bricks are (A) Less susceptible to chemical attack by molten fluxes and gases etc (B) Very strong (C) Having very high thermal conductivity (D) None of these
Last Answer : (D) None of these
Description : Resistance to fusion of the refractory under a steady rising temperature condition is called (A) Spalling (B) Refractoriness (C) Both (A) & (B) (D) Neither (A) nor (B)
Last Answer : (B) Refractoriness
Description : Refractory bricks having high thermal conductivity is desirable, when it is to be used in the (A) L.D. converter (B) Blast furnace (C) Rotary kiln (D) Recuperator
Last Answer : (D) Recuperator
Description : Refractory bricks burnt at very high temperature have got (A) Greater resistance to corrosion by slags (B) Less resistance to corrosion by slags (C) High spalling tendency (D) None of these
Last Answer : (A) Greater resistance to corrosion by slags
Description : A furnace is made of a refractory brick wall of thickness 0.5 metre and thermal conductivity 0.7 W/m.°K For the same temperature drop and heat loss, this refractory wall can be replaced by a layer of diatomaceous earth of ... and thickness __________ metre. (A) 0.01 (B) 0.1 (C) 0.25 (D) 0.5
Last Answer : (B) 0.1
Description : Most of the phosphorous present in the blast furnace burden enters into (A) Hot metal (B) Flue gases (C) Slag (D) Refractory lining
Last Answer : (A) Hot metal
Description : __________ is used for tying the steel columns to concrete foundation. (A) Grouting (B) Eyebolt (C) Anchor bolts (D) Refractory castables
Last Answer : C) Anchor bolts
Description : __________ property of steel increases by addition of large amount of silicon in it. (A) Mechanical (B) Machining (C) Magnetic (D) Refractory
Description : The refractory lining of the bottom in a basic electric arc furnace is made of (A) Silica (B) Alumina (C) Magnesia (D) Fireclay
Description : When the nurse observes that the patient's systolic blood pressure is less than 80-90 mm Hg, respirations are rapid and shallow, heart rate is over 150 beats per minute, and ... d) Irreversible In refractory or irreversible shock, the patient requires complete mechanical and pharmacologic support.
Last Answer : a) Compensatory In compensatory shock, the patient’s blood pressure is normal, respirations are above 20, and heart rate is above 100 but below 150.
Description : Which stage of shock is best described as that stage when the mechanisms that regulate blood pressure fail to sustain a systolic pressure above 90 mm Hg? a) Progressive In the progressive stage of ... which organ damage is so severe that the patient does not respond to treatment and cannot survive.
Last Answer : a) Progressive In the progressive stage of shock, the mechanisms that regulate blood pressure can no longer compensate, and the mean arterial pressure falls below normal limits.
Description : What is Refractory Phase?
Last Answer : After the action potential changes the neuron from negative to positive there is a refractory phase where it changes back to negative. At the beginning of this period it is impossible for another ... phase where it is possible to send another signal but more excitation than normal is needed.
Description : Pick up the metal refractory from the following: (A) Molybdenum (B) Tungsten (C) Zirconium (D) All of these
Last Answer : Answer: Option D
Description : Refractory bricks are used for (A) Retaining walls (B) Columns (C) Piers (D) Combustion chambers
Description : Refractory bricks are (A) Neutral refractory bricks (B) Acid refractory bricks (C) Basic refractory bricks (D) All the above
Description : Refractory bricks resist (A) High temperature (B) Chemical action (C) Dampness (D) All the above
Last Answer : Answer: Option A
Description : Sewer pipes are made of (A) Earthen ware (B) Stone ware (C) Refractory clay (D) All the above
Last Answer : Answer: Option B
Description : The sequence of refractory materials according to increasing melting points is: (A) Dolomite, Magnesia, Bauxite, Chromites (B) Bauxite, Chromites, Dolomite, Magnesia (C) Magnesia, Bauxite, Dolomite, Chromites (D) None of these
Description : Pick up the correct statement from the following: (A) The baked earth is called terra-cotta (B) The articles prepared from clay which is burnt at low temperature and cooled down slowly, are called ... clays which as mixed with stone and crushed pottery, are called stone ware (D) All the above