Description : Addition of plasticisers to polymers results in partial neutralisation of intermolecular forces of attraction between the macro-molecules thereby increasing its (A) Tensile strength (B) Chemical resistance (C) Flexibility (D) All (A), (B) & (C)
Last Answer : (C) Flexibility
Description : Plasticisers are high boiling liquids added to plastic polymers to impart toughness and flexibility at ordinary temperature. Which of the following is not a plasticiser? (A) Ethylene glycol (B) Stearic acid estors (C) Tricresyl phosphate (D) Esters of phthalic acid
Last Answer : (A) Ethylene glycol
Description : Plasticisers are added to synthetic plastics to (A) Impart flexibility (B) Improve workability during fabrication (C) Develop new improved properties not present in the original resin (D) All (A), (B) and (C)
Last Answer : (D) All (A), (B) and (C)
Description : Plasticisers are added to synthetic plastics to (A) Impart flexibility (B) Improve workability during fabrication (C) Develop new improved properties not present in the original resins (D) All (A), (B) and (C)
Description : Vulcanisation of rubber does not increase its (A) Softness (B) Oxidation resistance (C) Weight & strength (D) Elasticity & water solubility
Last Answer : (A) Softness
Description : __________ are added in lacquers to remove film brittleness and to improve adhereness. (A) Film forming materials (B) Plasticisers (C) Diluents (D) Solvents
Last Answer : (B) Plasticisers
Description : While the thermosetting polymers are amorphous in nature, the thermoplastic polymers are either amorphous or crystalline. The crystalline polymers are characterised by the (A) Low impact strength (B) High flexibility (C) Better finish and surface appearance (D) High plastic deformation
Last Answer : A) Low impact strength
Description : Pick out the correct combination about the role of various additives used in polymers. (A) Plasticiser: increases the polymer strength (B) Heat stabiliser: increases the maximum service ... property of polymer but increases its weight (D) Lubricants: increases the flexibility of polymers
Last Answer : Option C
Description : . In a linear polymer, the monomeric units are linked together to form long straight chains. The cross linked or branched chain polymers compared to linear polymers have higher (A) Densities (B) Melting point (C) Tensile strength (D) Hardness, rigidity & brittleness
Last Answer : (D) Hardness, rigidity & brittleness
Description : Phosphates (e.g., tricresyl, tributyl, tetrabutyl, triphenyl etc.) are addedto polymers to act as (A) Hardeners (B) Anti-shrinkage agents (C) Plasticisers (D) Transparency improver
Last Answer : (C) Plasticisers
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 : Branched chain polymers compared to linear polymers have higher (A) Density (B) Tensile strength (C) Melting point (D) Degree of irregularity in atomic packing
Last Answer : (D) Degree of irregularity in atomic packing
Description : Branched chair polymers as compared to linear polymers have (A) Higher melting point (B) Higher tensile strength (C) Lower density (D) None of these
Last Answer : (C) Lower density
Description : Which of the following is not a primary essential property of a fibre? a. Flexibility b. Tensile strength c. Absorbency d. Cohesiveness
Last Answer : c. Absorbency
Description : Tempering of a material does not improve its (A) Machinability (B) Toughness (C) Internal stress level (D) Softness
Last Answer : A) Machinability
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
Description : Normalising does not __________ of a metal. (A) Improve machinability & tensile strength (B) Remove internal stresses (C) Refine the structure (D) Remove strains caused by cold working
Last Answer : Option B
Description : Lead is added to 60:40 brass primarily to improve (A) Machinability (B) Corrosion resistance (C) Fluidity (D) Strength
Last Answer : (A) Machinability
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 : Reduction in the grain size reduces the __________ of the material. (A) Fatigue resistance (B) Tensile strength (C) Creep resistance (D) All (A), (B) & (C)
Last Answer : (C) Creep resistance
Last Answer : (D) All (A), (B) & (C)
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 : Which of the following drugs is believed to improve microcirculation in peripheral vascular diseases by promoting RBC flexibility ? (a) Cyclandelate (b) Theophyline (c) Pentoxiphyline (d) Nicotinic acid
Last Answer : Ans: C
Description : The following drug is believed to improve microcirculation in peripheral vascular diseases by promoting RBC flexibility: A. Cyclandelate B. Theophylline C. Pentoxiphylline D. Nicotinic acid
Last Answer : C. Pentoxiphylline
Description : Amino resins are used in paper treatment to improve its (A) Wet tear and bursting strength (B) Folding endurance (C) Wet rub resistance (D) All (A), (B) & (C)
Description : Sizing material is incorporated in paper to (A) Impart resistance to penetration by liquids (B) Increase its thickness (C) Increase its flexibility & opacity (D) Increase its brightness
Last Answer : (A) Impart resistance to penetration by liquids
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 : Elastomers are (A) Thermosetting material (B) Exemplified by protein derivatives (C) Having high flexural strength (D) Having very high tensile strength and heat resistance
Last Answer : (C) Having high flexural strength
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 : 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 : Shock resisting steels should possess high (A) Hardness (B) Toughness (C) Tensile strength (D) Wear resistance
Last Answer : (B) Toughness
Description : Addition of lead, sulphur and phosphorus to low carbon steel helps in improving its (A) Corrosion resistance (B) Tensile strength (C) Machinability (D) Compressive strength
Last Answer : (C) Machinability
Description : Presence of cobalt in steel improves its (A) Cutting ability (B) Corrosion resistance (C) Tensile strength
Last Answer : (A) Cutting ability
Description : Failure of a material is termed as fatigue failure, if it fails below the yield point. The resistance to fatigue failure of a material is measured by the (A) Ultimate tensile strength (U.T.S.) (B) Endurance limit (C) Elastic limit (D) None of these
Last Answer : (B) Endurance limit
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)
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 : Fatigue resistance of a material is measured by the (A) Elastic limit (B) Ultimate tensile strength (C) Young's modulus (D) Endurance limit
Last Answer : (D) Endurance limit
Description : Young's modulus of a material is the measure of its (A) Stiffness (B) Malleability (C) Creep resistance (D) Tensile strength
Last Answer : Option A
Description : Pick out the wrong statement. (A) Fibrillation of fibre during paper manufacture is done to develop the strength in paper (B) Alkali consumption in digestion/cooking of bamboo is measured in terms ... both lignin & cellulose (D) Presence of sodium sulphate in pulp makes the pulp bleachability poor
Last Answer : (D) Presence of sodium sulphate in pulp makes the pulp bleachability poor
Description : Buffer solutions have constant acidity and alkalinity because: (1) they have fixed value of pH (2) these give unionised acid or base on reaction with added acid or alkali (3) acids and alkalies in these solutions are shielded from attack by other ions (4) they have large excess of H+ or OH– ions
Last Answer : these give unionised acid or base on reaction with added acid or alkali
Description : Rosin soap is added during paper manufacture to (A) Impart adhesive properties (B) Improve opacity (C) Impart resistance to penetration by liquids (D) None of these
Last Answer : (C) Impart resistance to penetration by liquids
Description : The resistance to fatigue of a material is measured by (a) elastic limit (b) Young's modulus (c) ultimate tensile strength (d) endurance limit
Last Answer : (d) endurance limit
Description : Weld decay will cause which of the following problems? a) A reduced resistance to corrosion b) a lower tensile strength c) The toughness is reduced d) The hardness will increase
Last Answer : a) A reduced resistance to corrosion
Description : High copper amalgam lasts longer than low copper amalgam because of:** A. Increased compressive strength B. Increased corrosion resistance C. High creep D. Increased tensile strength E. Decreased setting expansion
Last Answer : A. Increased compressive strength
Description : Copper has very low (A) Malleability (B) Ductility (C) Tensile strength (D) Thermal & electrical conductivity
Last Answer : (C) Tensile strength
Description : Cast iron is (A) Used for making shock resisting parts (B) Manufactured in cupola and is brittle (C) Having compressive strength more than its tensile strength (D) All (A), (B) & (C)
Description : With increasing carbon percent in steel beyond 0.8%, its ultimate tensile strength (UTS) and __________ is not affected. (A) Impact strength (B) Percent elongation (C) Hardness (D) Both 'b' & 'c'
Last Answer : (A) Impact strength
Description : In case of brasses, with decreasing zinc percentage and increasing copper percentage, its __________ increases. (A) Percentage elongation (B) Brinell hardness (C) Tensile strength (D) All 'a', 'b' & 'c'
Last Answer : (A) Percentage elongation
Description : Primary designation of steel is based on its (A) Hardness & tensile strength (B) Carbon content (C) Iron content (D) Alloying elements content
Last Answer : (D) Alloying elements content Sh