Description : Vulcanisation of rubber (A) Decreases its tensile strength (B) Increases its ozone & oxygen reactivity (C) Increases its oil & solvent resistance (D) Converts its plasticity into elasticity
Last Answer : (D) Converts its plasticity into elasticity
Description : Fillers such as zinc oxide and carbon black are added to the crude natural rubber before vulcanisation in order to improve its (A) Elasticity (B) Strength (C) Plasticity (D) Weathering characteristics
Last Answer : (D) Weathering characteristics
Description : Vulcanisation of rubber does not increase its (A) Elasticity (B) Plasticity (C) Ductility (D) None of these
Last Answer : (B) Plasticity
Description : Vulcanisation of rubber decreases its (A) Tensile strength (B) Resistance to organic solvents (C) Tackiness (D) Working temperature range
Last Answer : (C) Tackiness
Description : __________ of rubber decreases after its vulcanisation. (A) Resistance to the action of organic solvent (B) Tackiness (C) Maximum service temperature (D) Tensile strength
Last Answer : (B) Tackiness
Description : Plasticisers are added to polymers to improve their (A) Tensile strength (B) Softness & flexibility (C) Acid resistance (D) Alkali resistance
Last Answer : (B) Softness & flexibility
Description : Peptizers like aromatic mercaptans (e.g. thiophenes) are added in rubber to (A) Protect rubber goods from attack by oxygen & ozone present in the atmosphere (B) Reduce its viscosity to ... processing (C) Reduce the time of vulcanisation and quantity of vulcanising agent (D) Increase its viscosity
Last Answer : (B) Reduce its viscosity to permit easier processing
Description : Styrene-butadiene-rubber (SBR) as compared to natural rubber has (A) Poorer tensile strength (B) Poorer resistance to oxidation (C) Greater amount of heat build-up under heavy loading (D) All (A), (B) and (C)
Last Answer : (D) All (A), (B) and (C)
Description : The process involved in converting rubber into a thin sheet or coating it on fabric is called (A) Extrusion (B) Mastication (C) Calendaring (D) Vulcanisation
Last Answer : (C) Calendaring
Description : Vulcanisation of raw rubber makes it (A) Soft (B) Less elastic (C) Plastic (D) Tacky
Last Answer : (B) Less elastic
Description : Most commonly used rubber vulcanisation agent is (A) Sulphur (B) Bromine (C) Platinum (D) Alumina
Last Answer : (A) Sulphur
Description : Aluminium alloy is one of the most suitable materials of construction for aircrafts mainly due to its (A) High strength to weight ratio (B) Low temperature strength properties (C) Its ability ... rolled, forged & stamped (D) High strength and corrosion & oxidation-resistance at elevated temperature
Last Answer : (A) High strength to weight ratio
Description : . Plasticisers are added to paints to (A) Make it corrosion resistant (B) Make glossy surface (C) Give elasticity & prevent cracking of the film (D) Increase atmospheric oxidation
Last Answer : (C) Give elasticity & prevent cracking of the film
Description : Neoprene which is used for making shoe heels & belts is superior to natural rubber in its stability to aerial oxidation and resistance to oils & other solvents. The monomer used for making neoprene is (A) Chloroethane (B) Chloroprene (C) Isoprene (D) None of these
Last Answer : (B) Chloroprene
Description : In vulcanisation, with which the natural rubber is heated? -Do You Know?
Last Answer : answer:
Description : In vulcanisation of rubber,
Last Answer : In vulcanisation of rubber, A. sulphur reacts to form new compound B. sulphur cross-links are ... layer over rubber D. all the statements are correct
Description : Which one of the following statements is not correct? Vulcanisation of rubber makes it - (1) soft and flexible (2) strong and hard (3) chemical resistant (4) withstand higher temperatures
Last Answer : (1) soft and flexible Explanation: In order to give more strength and more elasticity, natural rubber is heated with sulphur or sulphur compounds at 150°C temperature. Vulcanized rubber has good ... of vulcanized rubber is enhanced up to 100°C. It has good resistance to organic solvents.
Description : In vulcanisation process, rubber can be hardened by adding - (1) Nitrogen (2) Silicon (3) Sulphur (4) Alcohol
Last Answer : (3) Sulphur Explanation: In order to give more strength and more elasticity, natural rubber is heated with sulphur or sulphur compounds at 150°C temperature. Vulcanized rubber has good tensile strength.
Description : In vulcanisation, with which the natural rubber is heated?
Last Answer : Sulphur
Description : In vulcanisation process, rubber can be hardened by adding (1) Nitrogen (2) Silicon (3) Sulphur (4) Alcohol
Description : Which one of the following statements is not correct? Vulcanisation of rubber makes it (1) soft and flexible (2) strong and hard (3) chemical resistant (4) withstand higher temperatures
Last Answer : soft and flexible
Description : Softness of silver can be converted into hardness by alloying it with small quantity of (A) Copper & nickel (B) Zinc (C) Aluminium (D) Tin
Last Answer : (A) Copper & nickel
Description : Due to its excellent permeability to air/gas and oxidation resistance, the tubes of automobile tyres is made of (A) Cold SBR (B) Butyl rubber (C) Bunai N (D) Buna S
Last Answer : (B) Butyl rubber
Description : Tempering of a material does not improve its (A) Machinability (B) Toughness (C) Internal stress level (D) Softness
Last Answer : A) Machinability
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 : 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 : This natural fiber obtained from the stems of a plant of the nettle family has found popularity in modern fibers with a high wet strength, absorbent but dries quickly, it can be spun or woven, has a high rot ... a source of heat or power? w) Plutonium-238 x) Strontium-90 y) Cesium-137 z) Uranium-235
Last Answer : ANSWER: W -- PLUTONIUM-238
Description : Conditioners like finely divided peat are added to the fertiliser to (A) Counteract burning (B) Avoid caking & hardening (C) Produce bulk (D) Increase its solubility
Last Answer : (B) Avoid caking & hardening
Description : Styrene butadiene rubber (SBR) as compared to natural rubber has (A) Poor tensile strength (B) Poorer resistance (C) Greater amount of heat build up heavy loading (D) All (A), (B) and (C)
Description : Pick out the correct statement. (A) Materials exhibiting high elasticity obey Hooke's law (B) The elastic behaviour of rubber under compression is the same as its behaviour under tension (C) ... to its plastic deformation (D) The stress required to cause plastic flow in polycrystalline material is
Last Answer : Option B
Description : __________ practically possess no elasticity. (A) Vulcanite or ebonite (B) Spandex fibre (C) Polysulphide rubber (D) Epoxy resin
Last Answer : (A) Vulcanite or ebonite
Description : How does a musical concept dynamics covers only the overall loudness or softness of a piece of music?
Last Answer : Need answer
Description : A doctor advises a patient to take plenty of citrus fruits, guavas, tomatoes and amlas over a period of two months regularly. What do you think is the complaint of the patient? (a) Softness and ... skin of angle of mouth (d) Extreme weakness, swelling and pain in legs, loss of appetite, headache
Last Answer : Ans:(b)
Description : To obtain softness and ductility, metals art a) tempered b) hardened c) enamelled d) hard faced
Last Answer : b) hardened
Description : Presence of manganese in alloy steel improves its (A) Corrosion resistance (B) Cutting ability (C) Abrasion resistance & toughness (D) Elasticity & creep resistance
Last Answer : (C) Abrasion resistance & toughness
Description : Heating rubber with sulphur for the bet- terment of its properties ike tensile steqasbh: hardness; elasticity etc. is called as?
Last Answer : Vulcanisation
Description : In an interphase mass transfer process, the lesser the solubility of a given solute in a liquid, the higher are the chances that the transfer process will be (A) Liquid phase resistance-controlled (B) Gas phase resistance controlled (C) Impossible (D) Driven by a non-linear driving forc
Last Answer : (B) Gas phase resistance controlled
Description : Pick out the wrong statement: (A) Absorption factor is constant, when the equilibrium and operating lines are straight (B) In case of a stripper, the equilibrium curve is always below ... (D) In the absorption of low solubility gases, the liquid film is the controlling resistance
Last Answer : (B) In case of a stripper, the equilibrium curve is always below the operating line
Description : Which of the following mechanical properties of a material is most structure insensitive? (A) Modulus of elasticity (young's modulus) (B) Toughness (C) Percentage reduction of area (D) Tensile strength
Last Answer : (A) Modulus of elasticity (young's modulus)
Description : With increase in temperature, the solubility of gases in liquids, at fixed pressure (A) Increases (B) Decreases (C) Remain same (D) Either (A) or (B), depends on the system
Last Answer : (B) Decreases
Description : Absorption accompanied by heat evolution results in (A) Increased capacity of the absorber (B) Increase in equilibrium solubility (C) Decrease in equilibrium solubility (D) None of these
Last Answer : (C) Decrease in equilibrium solubility
Description : With increase in temperature, the mutual solubility of two liquids (A) Increases (B) Decreases (C) Remains unchanged (D) Decreases exponentially
Last Answer : (A) Increases
Description : Pick out the wrong statement. (A) In solvent extraction, the distribution co-efficient should be as large as possible for solvent economy (B) With increase in pressure, the solubility of ... in distillation column (D) The capacity of a distillation column is maximum at total reflux
Last Answer : (D) The capacity of a distillation column is maximum at total reflux
Description : Solubility of a substance which dissolves with an increase in volume and liberation of heat will be favoured by the (A) Low pressure and high temperature (B) Low pressure and low temperature (C) High pressure and low temperature (D) High pressure and high temperature
Last Answer : (B) Low pressure and low temperature
Description : Mastication of rubber means (A) Its softening (B) A treatment to retard its deterioration due to oxidation (C) Improving its curing rate (D) Depression of its freezing point
Last Answer : (A) Its softening
Description : Presence of high concentration of ozone and smog in atmospheric air causes the (A) Embrittlement & decrease of folding resistance of paper (B) Cracking of rubber products (C) Fading of dye on textiles (D) Damage of electrical insulator on high tension power line
Last Answer : (B) Cracking of rubber products
Description : Vulcanisation was developed by?
Last Answer : Charles Good Year
Description : What is elasticity in polymers generally related to amount of hydrogen bonding between different subunits number of subunits in the polymer chain its greater tensile strength the synthetic composure?
Last Answer : amount of hydrogen bonding between different subunitsnumber of subunits in the polymer chainits greater tensile strengththe synthetic composure