211. Branched chain polymers compared to linear polymers have higher density. tensile strength. melting point. degree of irregularity in atomic packing. ✅ The correct answer is option D.
212. In a cross linked polymer, the monomeric units are linked together to constitute a three dimensional network. Which of the following is a cross-linked polymer ? Bakelite (phenol formaldehyde) Polyester Polythene Nylon-6 ✅ The correct answer is option A.
213. Orlon is a copolymer. a condensation polymer. obtained by polymerising vinyl cyanide. all (a), (b) and (c). ✅ The correct answer is option C.
214. Which of the following is not a natural polymer ? Nucleic acids e.g. RNA and DNA Polysaccharides Polyisoprene Polyurethane ✅ The correct answer is option D.
215. Condensation polymerisation is not involved in the manufacture of teflon polythene terylene nylon ✅ The correct answer is option B.
216. Polyvinyl acetate is never used for making moulded articles fibres adhesives all (a), (b) & (c) ✅ The correct answer is option A.
217. Which of the following is a copolymer ? Polystyrene SBR P.T.F.E. Polypropylene ✅ The correct answer is option B.
218. Styrene butadiene rubber (SBR) as compared to natural rubber has poor tensile strength. poorer resistance. greater amount of heat build up heavy loading. all (a), (b) ana (c). ✅ The correct answer is option D.
219. __________ tubes are good substitude for human blood vessels onrheart by-pass operation. PVC Polythene Teflon/dacron Polystyrene ✅ The correct answer is option C.
220. Which of the following low molecular weight (<104 ), soft & waxy polymer is used in chewing gum ? Cellulose acetate Polyvinyl acetate Thiokol PVC ✅ The correct answer is option B.