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 : Thermosetting materials (A) Are cross-linked molecules (B) Soften on application of heat (C) Are solvent soluble (D) None of these
Last Answer : (A) Are cross-linked molecules
Description : Cross linked polymers are (A) Thermoplastic (B) Thermosetting (C) Either (A) or (B) (D) Fibres only
Last Answer : (B) Thermosetting
Description : Pick out the wrong statement. (A) Linear polymers are formed from bifunctional groups only and are normally thermoplastic (B) Cross-linked branched chain polymers are either elastometric or ... (D) Dibasic acids reacts with dihydric alcohols to give polyesters using addition polymerisation reaction
Last Answer : D) Dibasic acids reacts with dihydric alcohols to give polyesters using addition polymerisation reaction
Description : Cross linked polymers formed from bi-and trifunctional groups in which cross-linkage in three dimensions via few chemical bonding across linear chains occur imparts to the polymer __________ properties. (A) Thermoplastic (B) Thermosetting (C) Elastometric (D) Brittleness
Last Answer : (C) Elastometric
Description : What is the purpose of plasticizers? (a) Harden plastics (b) Soften plastics (c) Initiate polymerizations (d) Cross-link polymer chains
Last Answer : Soften plastics
Description : Differentiate between any five of the following: a) Thermoplastics and thermosetting plastics b) Lunar eclipse and solar eclipse c) Asteroid and meteorite d) Renewable and non-renewable energy resources e) Endothermic and exothermic reactions f) Star and planet g) Nuclear fission and nuclear fusion
Last Answer : a) Thermoplastics and thermosetting plastics: Thermoplastics: Thermoplastics can be repeatedly softened by heating and hardened by cooling.Thermoplastic molecules, which are linear or slightly branched, do ... or explode in midair. Remains of meteoroids that reach the surface are called meteorites.
Description : Identify the group in which all the polymers mentioned can be used to make fibres. (A) Butadiene copolymers, Polyamides, Urea-formaldehyde (B) Cellulose derivatives, Polyisoprene, Polyethylene (C) Cellulose derivatives, Polyamides, Polyurethane (D) Polypropylene, Poly vinyl chloride, Silicon
Last Answer : (B) Cellulose derivatives, Polyisoprene, Polyethylene
Description : The purpose of nitriding the steel is to (A) Harden its surface (B) Soften its surface (C) Improve its reliability (D) None of these
Last Answer : (A) Harden its surface
Description : The thermosetting plastic (A) Becomes rigid when moulded at suitable pressure and temperature (B) At 127°C to 177°C permanently set and further application of heat does not soften it (C) Chars at 343°C (D) All the above
Last Answer : Answer: Option D
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 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 : Polymers are classified into four categories namely thermosetting, thermoplastic, elastomer and fibre depending upon their (A) Molecular sizes (B) Magnitude of intermolecular forces (C) Resistance to heat (D) Polymerisation mechanism
Last Answer : (B) Magnitude of intermolecular forces
Description : Thermosetting resins/polymers as compared to thermoplastic ones are (A) Soluble in all organic solvents (B) More brittle (C) Formed by addition polymerisation only (D) Easily reshaped & reused
Last Answer : (B) More brittle
Description : Linear polymers are normally (A) Thermosetting (B) Thermoplastic (C) Elastometric (D) Having extremely high softening poin
Last Answer : (B) Thermoplastic
Description : Thermosetting polymers as compared to thermoplastic polymers (A) Are formed by addition polymerisation (B) Have three dimensional structure (C) Have linear structure (D) None of these
Last Answer : (B) Have three dimensional structure
Description : Thermosetting resins are those polymers, which (A) Do not increase in plasticity with rise in temperature (B) Allow slip to occur between molecules (C) Do not take on a permanent set (D) None of these
Last Answer : (A) Do not increase in plasticity with rise in temperature
Description : Thermosetting polymers are (A) Injection moulded (B) Cast molded (C) Extruded (D) None of these
Last Answer : (B) Cast molded
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 : List any four properties of thermosetting polymers.
Last Answer : Properties of thermosetting polymers: 1.Very poor elasticity 2.sronger attractive forces between chains 3. not soluble in organic compounds 4.can not be remoulded 5. these polymers produces by condensation polymerization
Description : Differentiate between Thermoplastic and Thermosetting polymers.
Last Answer : Differentiate between Thermosetting and Thermoplastic polymers: Thermosetting Thermoplastic Polymers which once mould /shaped do not soften when heated and thus cannot be reshaped Polymers whose ... tri, tetra or poly functional. Monomer used in this polymer bi functional.
Description : Distinguish between Homopolymers and Copolymers.
Last Answer : Homopolymers Copolymers 1. The polymers which are form by only one type of monomers Eg. Teflon & PVC 1. The polymers which are form by two or more types of monomers .Eg. Terrylene & Buna-S
Description : Define Copolymers?
Last Answer : Ans: The polymer is obtained by two or more different monomers.
Description : Define Copolymers.Give two examples.
Last Answer : Ans: The Polymer in which repeating units are combined with two or more differents types of monomers Eg. Polyster and terrylene(Dacron)
Description : Which of the following is used as base material in Selective laser sintering (SLS)? a.Photopolymer b.Thermoplastics, Metal powders c.Titanium alloys d.Various materials
Last Answer : b.Thermoplastics, Metal powders
Description : Which of the following is used as base material in Stereolithography (SLA) process? a.Thermoplastics , Metals powders b.Thermoplastics , Eutectic metals. c.Titanium alloys d.Photopolymer
Last Answer : d.Photopolymer
Description : Which of the following is not thermoplastics?
Last Answer : Which of the following is not thermoplastics? A. Cellulose acetate B. Nitrocellulose C. Polyvinyl acetate D. Phenol formaldehyde polymer
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 : In sub-cooled boiling, (A) Temperature of the heating surface is less than the boiling point of the liquid (B) Temperature of the heating surface is more than the boiling point of the liquid (C) ... from heating surface are absorbed by the mass of the liquid (D) Very large vapour space is necessary
Last Answer : (B) Temperature of the heating surface is more than the boiling point of the liquid
Description : In the heating process of the ________type a simple method of temperature control is possible by means of a special alloy which loses its magnetic properties at a particular high temperature and regains ... ) core type induction furnace (C) coreless induction furnace (D) high frequency eddy current
Last Answer : Ans: D Magnetic property of alloy changes with change of the temperature and Heat is produced due to eddy current = i2R and i α f2
Description : In self cooled motors the cooling time constant is about ______ than the heating time constant because cooling conditions are worse at standstill. (a) 2 to 3 times greater (b) 3 to 4 times greater (c) 4 to 5 times greater (d) none of the above
Last Answer : (a) 2 to 3 times greater
Description : Which property of Zeolites make it suitable to soften hard water?
Last Answer : Ans-Sodium ions are exchanged by calcium and magnesium ions
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 : Which of the following is a thermosetting polymer? (a) Bakelite (b) Nylon-6,6 (c) Polyethylene (d) Teflon
Last Answer : Bakelite
Description : Bakelite has the following characteristics (a) A polymer made from phenol and formaldehyde (b) A thermosetting plastic (c) Can be used as an adhesive (d) All of the above
Last Answer : All of the above
Description : What are some signs that indicate you need to harden up?
Last Answer : I’m already hard.
Description : Does chocolate ganache harden?
Last Answer : Yes, this is ganache. Ganache kind of hardens, but is still soft. I believe it is exactly what you are looking for. Truffles (the ones rolled in cocoa powder) are made from ganache. I hope that ... They are soft enough to melt against your skin or on your tongue, but hard enough to keep shape.
Description : If i bruise alot, will it eventually harden and stop bruising?
Last Answer : I don’t know if that applies to bruises. I know it’s true for cuts, though.
Description : How to tell if butternut squash is ripe and how to harden off and store?
Last Answer : Need Answer
Description : what use to harden my yard
Last Answer : Try adding clay to the areas that are most suspect to the water damage. -Birdy
Description : Name the mineral which is used to harden steel during manufacturing -SST 10th
Last Answer : Manganese is required to harden steel during manufacturing.
Description : If I make a ceramic statue and don't burn it because I don't have a kiln, will it harden too? Thank you
Last Answer : Yes dries and hardens. However, if it absorbs moisture or gets wet, it will soften again.
Description : I need to improve my immunity a little bit. How to do it? Should I alternate hot and cold showers? Or Only a cold shower?
Last Answer : Rather than milling yourself in the shower, I recommend the sauna. I will add: Of course, the sauna hardens ... Improving immunity is a question (even with Scottish sprays or showers) - but if I accept that "what doesn't kill you will make you stronger", then definitely yes. ;-)
Description : What school did James harden go to?
Last Answer : He went to artesia high in California
Description : Did James Harden die?
Last Answer : James Harden-Hickey died in 1898.
Description : How good is James Harden?
Last Answer : Really Good.
Description : Which of the problems listed will occur if a lead-acid battery is allowed to remain in a discharged condition for a long period of time? A. The battery may be unable to accept a full charge ... . C. The concentrated sulfuric acid will attack the lead peroxide plates. D. The separators will harden.
Last Answer : Answer: A
Description : The main purpose of galvanising iron sheets is to (A) Harden the surface (B) Increase its glossiness and lustre (C) Prevent the action of water (D) Prevent the action of oxygen
Last Answer : (C) Prevent the action of water