Description : Which of the following types of polymers has the strongest inter particle forces? (A) Elastomers (B) Fibres (C) Thermoplastics (D) Thermosetting polymers
Last Answer : (D) Thermosetting polymers
Description : Out of all the elastomers, natural rubber has the longest elongation range & flexibility of the order of __________ percent. (A) 1-1000 (B) 1000-1500 (C) 1500-2000 (D) 2000-2500
Last Answer : (A) 1-1000
Description : Pick out the wrong statement. (A) Pure rubber is as useless as pure gold as a material of construction (B) Thermal conductivity of aluminium is higher than that of copper; henceit is ... has poor weldability (D) Reinforced plastics are made from both thermoplastic as well as thermosetting plastics
Last Answer : (B) Thermal conductivity of aluminium is higher than that of copper; henceit is increasingly used for utensil making
Description : Which of the following has the weakest intermolecular forces? (A) Polyisoprene (B) Nylon-66 (C) Polystyrene (D) Bakelite
Last Answer : (A) Polyisoprene
Description : Creep is not exhibited at low temperature by (A) Rubber (B) Acrylics (C) Lead (D) Plastics
Last Answer : (C) Lead
Description : A chain growth polymerisation reaction consists of three different types of reaction namely initiation reaction, propagation reaction & termination reaction. Chain growth polymerisation reaction is not involved ... Siloxane elastomers (B) Polyamides (C) Vinyl polymers (D) Urea-formaldehyde resins
Last Answer : (D) Urea-formaldehyde resins
Description : In the insulin molecule, the number of interchain disulphide brides is (A) 1 (B) 2 (C) 3 (D) 4
Last Answer : Answer : B
Description : which type of friction forces are the strongest and the weakest?
Last Answer : there are four types of friction: static, sliding, rolling, and air resistance. Static friction is the strongest and rolling friction is weakest.
Description : The weakest interparticle forces are present in :
Last Answer : The weakest interparticle forces are present in : A. thermosetting polymers B. themoplastic polymers C. fibres D. elastomers
Description : Which of the following exhibits the weakest intermolecular forces?
Last Answer : Which of the following exhibits the weakest intermolecular forces? A. `H_(2)O` B. `NH_(3)` C. He D. HCl
Description : Where shows the correct order of forces from weakest to strongest?
Last Answer : strong nuclear, weak nuclear, electrostatic, gravitational
Description : Which of these substances exhibits the weakest intermolecular forces? (a) NH3 (b) H2O (c) He (d) HCI
Last Answer : Ans:(c)
Description : The weakest of all fundamental forces is – (1) Gravitational force (2) Electrostatic force (3) Magnetic force (4) Nuclear force
Last Answer : (1) Gravitational force Explanation: In particle physics, fundamental interactions (sometimes called interactive forces or fundamental forces) are the ways that elementary particles interact with one another. ... weak interaction ("weak nuclear force"), and gravitation. All are non-contact forces.
Description : The weakest of all fundamental forces is (1) Gravitational force (2) Electrostatic force (3) Magnetic force (4) Nuclear force
Last Answer : Gravitational force
Description : Which of the following are conductors? a) Ceramics b) Plastics c) Mercury d) Rubber
Last Answer : c) Mercury
Description : Pick out the wrong statement. (A) Polymeric fibres are never produced by addition polymerisation (B) Property of tackiness is exhibited by uncured rubber (C) Sharp melting point is not observed in thermoplastic polymers (D) Polythene generally has an excellent resistance to ultra violet rays
Last Answer : (A) Polymeric fibres are never produced by addition polymerisation
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 : How do Wire Rope Isolators (WRI) compare to elastomers regarding use over a broad temperature range?
Last Answer : The WRI can be used over a greater temperature range with less change in performance. Proper elastomer selection will make elastomers useful for most applications.
Description : What are elastomers ? Give one example.
Last Answer : Ans: The rubber like material which are elastic in nature. Eg. Natural rubber.
Description : Elastomers can extend upto (A) Five times their original dimensions (B) Seven times their original dimensions (C) Ten times their original dimensions (D) Three times their original dimensions
Last Answer : Answer: Option C
Description : Liquid crystal elastomers 4D printing material achieve their activation due to a. Light b. Heat c. Electrical d. All of the above
Last Answer : Ans:- d. All of the above
Description : Elastomers are:** A. Hydrophilic B. Hydrophobic C. Water-loving impression material D. Potassium alginates E. None of the above
Last Answer : B. Hydrophobic
Description : Visco-elastic behaviour exhibited by plastics is a __________ like behaviour. (A) Solid (B) Liquid (C) Combination of solid & liquid (D) Neither solid nor liquid
Last Answer : (C) Combination of solid & liquid
Description : Plastics are (A) Used in very high temperature applications (B) Non-biodegradable (C) Not suitable for drainage pipe manufacture (D) All (A), (B) & (C)
Last Answer : (B) Non-biodegradable
Description : In case of wet spinning of polymers, the polymer solution is forced through spinnerates into, a coagulating bath to give a filament form. Wet spinning is not used in case of the __________ fibres. (A) Viscose rayon (B) Acrylic (C) Polyvinyl acetate (D) Saturated polyeste
Last Answer : (D) Saturated polyeste
Description : Melt spinning of polymers involves the forcing of polymer melt through spinnerates (fine holes) into an atmosphere kept at a temperature lower than the melting point of the polymer, which causes the fine diameter ... the __________ fibres. (A) Acrylic (B) Polyester (C) Nylon 6:6 (D) Polypropylene
Last Answer : (A) Acrylic
Description : In case of dry spinning of polymers, the polymer solution in a volatile solvent is forced through the spinnerates into a warm air chamber, where the solvent evaporates leaving behind the polymer in the filament ... is used for __________ fibres. (A) Polythene (B) PVC (C) Rayon (D) Polyvinyl acetate
Last Answer : (B) PVC
Description : Pick out the wrong statement. (A) Surface tension of a liquid is because of the difference in magnitude of adhesive & cohesive forces (B) A hydrometer used for the determination of ... Turbulent fluid flow is characterised by the rapid fluctuation of instantaneous pressure & velocity at a poin
Last Answer : (C) In case of unsteady fluid flow, the velocity at any given point does not change with time
Description : The weakest sound that can be heard by a person in a quiet environment is equivalent to __________ decibel. (A) 1 (B) 5 (C) 10 (D) 50
Last Answer : A) 1
Description : Bakelite (phenol-formaldehyde) resin cannot be used as (A) Decorative paint (B) Decorative laminates (C) Electrical insulation (D) Glass reinforced plastics
Last Answer : (A) Decorative paint
Description : __________ moulding is used for shaping of thermosetting plastics exclusively. (A) Compression (B) Injection (C) Transfer (D) Extrusion
Last Answer : (C) Transfer
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 : Pick out the correct statement. (A) Plastics are good conductors of heat and electricity (B) All the polymers are highly crystalline in nature (C) Polymers can be vaporised by heating to ... D) The liquid polymer becomes greasy, then waxy and finally solid on increasing the degree of polymerisation
Last Answer : (D) The liquid polymer becomes greasy, then waxy and finally solid on increasing the degree of polymerisation
Description : Most of the plastics are safe to be used upto a maximum temperature of __________ °C. (A) 100 (B) 150 (C) 350 (D) 450
Last Answer : (B) 150
Description : Molecular weights of plastics ranges from (A) 1000 to 5000 (B) 5000 to 1000 (C) 20000 to 25000 (D) 10 9 to 10
Last Answer : (C) 20000 to 25000
Description : Which of the following additives are added to plastics to make it impervious to X-rays? (A) Asbestos (B) Barium salt (C) Carborundum (D) Phthalic acid
Last Answer : (B) Barium salt
Description : __________ moulding process cannot be used for thermoplastic plastics. (A) Compression (B) Extrusion (C) Injection (D) None of these
Last Answer : (C) Injection
Description : Visco-elastic behaviour of materials which is time dependent is common in (A) Plastics (B) Crystalline solid (C) Non-crystalline solids (D) Non-crystalline organic polymer
Last Answer : (D) Non-crystalline organic polymer
Description : Hard pitch is used for making (A) Pulverised fuel (B) Perfumes (C) Insecticides (D) Plastics
Last Answer : (A) Pulverised fuel
Description : Pumping of a corrosive liquid is generally preferred to be done by a __________ pump, as it can be made of a variety of materials including plastics. (A) Piston (B) Gear (C) Positive displacement (D) Sump
Last Answer : (B) Gear
Description : Molecular weight of plastics ranges from (A) 5000 to 10000 (B) 20000 to 250000 (C) 500 to 5000 (D) 106 to 109
Last Answer : (B) 20000 to 250000
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 : Exposure to __________ accelerates the degradation of plastics. (A) Ultraviolet radiation (B) High atmospheric temperature (C) High ambient temperature (D) Damp atmosphere
Last Answer : A) Ultraviolet radiation
Description : Plastics as a material of construction suffer from the drawback of low (A) Machinability (B) Density (C) Strength (D) Plastic deformatio
Last Answer : Option C
Description : On a cold day when the room temperature is 15°C, the metallic cap of a pen becomes much colder than its plastic body, though both are at the same temperature of 15°C, because - (1) metals ... metals (3) metals are good conductors of heat (4) plastics have a higher thermal conductivity than metals
Last Answer : (3) metals are good conductors of heat Explanation: On a chilly day, the room temperature is lower than our body temperature. Since metals have a higher coefficient of thermal conductivity than plastic, they ... from our fingers will flow to the metal cap much more quickly than to the plastic body.
Description : On a cold day when the room temperature is 15°C, the metallic cap of a pen becomes much colder than its plastic body, though both are at the same temperature of 15°C, because : (1) metals ... metals (3) metals are good conductors of heat (4) plastics have a higher thermal conductivity than metals
Last Answer : metals are good conductors of heat
Description : Centrioles are present only in animals. In such a case how the spindle fibres are held in the cell division of plants? -Biology
Last Answer : answer:
Description : Acrilan fibres used for making cloth, carpet & blankets, which is a hard, horny & high melting polymeric material is nothing but (A) Polyacrylonitrile (B) Polyamide (C) Saturated polyester (D) Alkyd resin
Last Answer : (A) Polyacrylonitrile
Description : Dacron (or Treylene) fibres as compared to nylon fibres have (A) Better heat & acid resistant properties (B) Poorer resistance to alkalis (C) Poorer dyeability (D) All (A), (B) and (C)
Description : Alkyd resin cannot be used for making (A) Plasticiser (B) Paint & varnish (C) Fibres (D) Film forming materials
Last Answer : (C) Fibres