Practice Test: Question Set - 05
1. A copolymer is formed by the combination of two or more monomer molecules
- (A) In a chain without the elimination of water
- (B) With the elimination of small amount of water
- (C) Of the same monomer by elimination of small molecules of water
- (D) None of these
2. 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 aliphatic character are more soluble in
aliphatic solvents, while those polymers having more aromatic character are
more soluble in aromatic solvents
- (C) Swelling tendency or solubility of polymers in a particular solvent
decreases with increase in molecular weight of the solvent
- (D) High molecular weight polymers on dissolving
gives solution of very low viscosity
3. Phosphates (e.g., tricresyl, tributyl, tetrabutyl, triphenyl etc.) are added to polymers to act as
- (A) Hardeners
- (B) Anti-shrinkage agents
- (C) Plasticisers
- (D) Transparency improver
4. 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)
5. The rate controlling step in the manufacture of silicone rubber is the
- (A) Polymer termination step
- (B) Condensation of siloxane to silicone
- (C) Initial hydrolysis of silicone monomer
- (D) None of these
6. The conversion of caprolactam in the above case is about __________ percent.
- (A) 25
- (B) 50
- (C) 70
- (D) 90
7. Viscosity of a polymer solution or melt
- (A) Decreases with increase in molecular weight
- (B) Decreases with increase in temperature
- (C) Increases with increase in temperature
- (D) Does not vary with temperature rise
8. Caprolactam, a raw material for the manufacture of nylon-6, is produced from
- (A) Phenol
- (B) Naphthalene
- (C) Benzene
- (D) Pyridine
9. Vulcanisation of rubber decreases its
- (A) Tensile strength
- (B) Resistance to organic solvents
- (C) Tackiness
- (D) Working temperature range
10. Polyvinyl alcohol is used as a
- (A) Cation/anion exchanger
- (B) Water soluble adhesive
- (C) Textile fibre
- (D) Non-sticky coating on frying pans
11. Which of the following is the most important rubber compounding ingredient which is used to improve wearing qualities of both natural rubber & SBR by imparting toughness?
- (A) Phosphorous
- (B) Carbon black
- (C) Pine oil
- (D) Rosin
12. 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?
- (A) Bakelite (phenol formaldehyde)
- (B) Polyester
- (C) Polythene
- (D) Nylon-6
13. Pick out the wrong statement.
- (A) Cold SBR is superior as compared to hot SBR
- (B) Polymerisation temperature can modify the properties of SBR
- (C) Production of cold SBR employs lower pressure as compared to that of
hot SBR
- (D) None of these
14. Molecular weights of plastics ranges from
- (A) 1000 to 5000
- (B) 5000 to 1000
- (C) 20000 to 25000
- (D) 109 to 1011
15. Temperature and gage pressure maintained during the manufacture of cold SBR (styrene butadiene rubber) are
- (A) 5°C and 1 kgf/cm2
- (B) -20°C and 1 kgf/cm2
- (C) 0°C and 1 kgf/cm2
- (D) 0°C and 3 kgf/cm2
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