| Post Name | Assistant Director (Plastic) - Industries and Commerce |
|---|---|
| Question Paper Code | 139/2023/OL |
| Category Code | 386/2021 |
| Date of Test | 7 August 2023 |
| Exam Type | Online Examination |
| Total Questions | 100 |
1
Which of the following is/are correct about intrinsic viscosity? (i) It is known as Staudinger index (ii) It has the reciprocal of concentration as dimension (iii) It is known as limiting viscosity number (iv) It is dynamic viscosity
Answer
D. All of the above
2
Which of the following is not correct about cationic polymerization? (i) Molecular weight depends on monomer concentration (ii) Molecular weight increases as temperature increases (iii) The process is exothermic (iv) As dielectric constant of solvent increases molecular weight increases
Answer
A. Only (ii)
3
Which of the following is used as a telogen in the polymerization of bromotriïŹuoroethylene?
Answer
B. BromotriïŹuoromethane
4
Which of the following is in the correct with respect to their Tg?
Answer
C. Polymethylmethacrylate>Polymethacrylate>Polyethylacylate >Polybutylacrylate
5
The unit of K value in Mark-Houwink equation is
Answer
A. /g
6
What is the molecular weight of polycaprolactum with degree of polymerisation 1000?
Answer
B. 113000
7
Which polymerization method is suitable for Polyacrylonitrile?
Answer
A. Anionic polymerization
8
The functionality of acetylene is
Answer
D. 4
9
Reference material used in NMR is
Answer
A. Tetramethylsilane
10
The polymer which is used in space suit is
Answer
D. Nomex
11
Which among the following have the lowest LOI?
Answer
C. Polyacetal
12
An exceptionally tough and transparent material used in heart valve and pace component is
Answer
C. Polysulphone
13
Which among the following is a best antidegradant against metal poison?
Answer
B. DNPD
14
The polymer which is used for water puriïŹcation
Answer
A. Polyacrylamide
15
Which among the following is not a photo conducting polymer?
Answer
B. Polythiophene
16
Which polymerization technique often result low molecular weight polymer?
Answer
D. Solution polymerization
17
Equal numbers of molecules with Mâ = 1000 and Mâ = 10000 are mixed. The weight average of the resulting polymer will be
Answer
A. 9182 g·molâ»Âč
18
Which of the following is correct about GPC (i) Polymer molecules are separated according to their size (ii) It is a primary method for the determination of molecular weight (iii) It is used for the determination of Mn and Mw (iv) It is used for the determination of MWD
Answer
B. (i), (iii) and (iv)
19
Which of the following bonds posses highest bond energy?
Answer
B. B-O
20
Ionic polymers are used for heterogeneous catalysis because of its __________ property
Answer
B. Ion-exchange capability
21
Natural rubber is chemically known as
Answer
A. Cis-1,4 polyisoprene
22
What is the role of ammonia in latex preservation?
Answer
D. All the above
23
In the latex concentration methods, which process involve only the removal of water
Answer
A. Evaporation
24
Which rubber among the following is used in products for which lightness of colour is important?
Answer
B. pale crepe rubber
25
The rubber containing 20% to 30% of an aromatic or naphthenic process oil is called
Answer
C. Oil-extended Natural Rubber
26
The principle of the Reclaiming processes is
Answer
B. Devulcanization
27
Choose wrong statement among the following (i) Elastomers exhibits slow recovery after extension (ii) Elastomers can be vulcanised (iii) Elastomeric properties are aïŹected by the Tg (iii) Mechanical properties of elastomers are due to cross-linked, long-chain, ïŹexible polymer molecules.
Answer
A. Only (i)
28
The polymeric materials, which combine the processability of thermoplastics and the functional performance of vulcanised rubbers are called
Answer
C. Thermoplastic elastomer
29
Polychloroprene rubber is popularly known as
Answer
B. Neoprene
30
Which synthetic rubber is also commonly known as Hypalon
Answer
D. Chlorosulphonated polyethylene
31
Example for ïŹame retardant used in rubber compounding
Answer
A. Antimony compounds
32
Conventional vulcanizing system containing
Answer
A. High sulfure/accelerator ratio
33
The additive used to improve the mixing and processing of the rubber compound is
Answer
C. Processing aid
34
Monomers of butyl rubber are
Answer
C. Isobutylene, isoprene
35
Blowing agents are used in the manufacture of
Answer
A. Sponge rubber
36
Name the person who discovered vulcanization
Answer
A. Charles Goodyear
37
EPDM stands for
Answer
A. Ethylene propylene diene monomer
38
Select inorganic rubber among the following
Answer
D. Silicon rubber
39
An example for a coplolymer
Answer
Question Cancelled
40
Tripsometer is used to determine
Answer
C. Rebound resilience
41
How much rolling resistance should be reduced to get 1% fuel eïŹciency?
Answer
C. 5% to 7%
42
Which method is preferred to make rubber products if less heat and more pressure is required for curing?
Answer
B. Water curing
43
Which material is better if we required a short circuit temperature up to 250°C in power cables?
Answer
A. Crosslinked polyethylene
44
Which is/are the eïŹective method/methods to control the 'nerve' during rubber processing?
Answer
D. All of these
45
K-value of PVC material recommended in insulating material using in low and medium voltage cables
Answer
C. 65 to 70
46
Field used in injection bottle cap is
Answer
C. Barium sulphate
47
Which is the preferred speed ratio of four roll calendar matachin where both side topping can do?
Answer
A. 2:3:3:2
48
Which is the optimal molar ratio of resorcinol to formaldehyde in nylon coated fabric used in rubber compound?
Answer
B. 1:2 to 1:3
49
Which chemical does reduce the dissociation temperature of DNPT in MC sheet?
Answer
C. Stearic acid
50
Which rubber is suitable for manufacturing inner liners for hot water washing hoses using in washing machines?
Answer
D. NBR
51
Which among the following is/are act as heat sensitizing agent in heat sensitized latex?
Answer
D. All of these
52
Which process is/are suitable for manufacturing baby soothers?
Answer
B. Heat sensitized dipping
53
Which is using for improving ïŹame resistance of latex foam?
Answer
D. Hydrated aluminum oxide
54
Which substance is/are added to improve pressure sensitive adhesion in latex-based adhesive?
Answer
C. Rosin derivatives
55
Which material is widely used in latex - based paper adhesives?
Answer
B. Cooked starch
56
Which material is widely used to make curing bags in tyre moulds?
Answer
B. Resin cured IIR
57
In hoses, if braid angle is greater than neutral then hose will have
Answer
B. Increased length and decreased diameter
58
Which adhesive is generally used when moulded and vulcanized rubber piece is directly adhered on the metal parts in rubber to metal bonded products?
Answer
A. Epoxy adhesive
59
Which type of accelerators are generally avoided in rubber to metal bonded products?
Answer
A. Thiurams
60
What is the role of Vulcastab L.S in casted latex products?
Answer
C. Wetting agent
61
Polypropylene produced commercially using a Ziegler-Natta catalyst is predominantly
Answer
C. Isotactic
62
The characteristics of condensation polymerization are given below (i) Only -C-C- linkages present in the polymer structure (ii) Use of bifunctional of polyfunctional monomers (iii) Elimination of a small by product molecule Which of the following is true?
Answer
B. (ii) and (iii)
63
As the polymer crystallinity increases, the brittleness of polymer
Answer
A. Increases
64
Consider the following two transitions from the "solid" to the liquid or rubbery state shown below on a plot of speciïŹc volume (Vs) vs temperature (T)
Answer
A. The transition X is Glass transition temperature (Tg) while transition Y is crystalline melting point (Tm)
65
Which of the following polymers would you except to be most suitable for the production of a rubber car bumper guard?
Answer
B. A random ethylene/propylene copolymer (50/50 composition) Tg Ë40ÂșC)
66
Which of the following material is not made by injection molding?
Answer
B. Tubes
67
Which one of the following is a condensation polymer?
Answer
A. Nylon
68
In blow molding, to inïŹate soft plastic, which medium is used?
Answer
A. Air
69
Which of the following types of molecular structure are present in thermosetting polymers?
Answer
C. Cross-linked polymers
70
Which one is the natural polyamide polymer?
Answer
B. Silk
71
A continuous and aligned glass ïŹber-reinforced composite consists of 30 vol% glass ïŹbers having a modulus of elasticity of 69 GPa and 70 vol% polyester resin that, when hardened, displays a modulus of 3.4 GPa. The modulus of elasticity of this composite in the longitudinal direction is
Answer
A. 23.1 GPa
72
Dry spinning is a process
Answer
C. Which involves dissolving the polymer into a solvent that can be evaporated
73
Which of the following statements about plasticizers is true?
Answer
A. Plasticizers increase the modulus while decreasing the glass transition temperature
74
For 1 inch schedule 40 PVC pipe and 1 inch schedule 80 PVC pipe which of the following statement is correct?
Answer
C. Schedule 80 PVC pipe has a smaller inside diameter than schedule 40 pipe
75
Select the correct option
Answer
A. PCTFE is a thermoplastic polymer and its repeating unit is
76
Which of the following statements is true for PVC-O pipes?
Answer
A. PVC-O pipes are obtained by the process of molecular orientation of UPVC to obtain a layered structure
77
Which of the following will not help in controlling the ïŹow lines in injection molding?
Answer
C. Decrease the nozzle diameter to reduce the melt ïŹow rate
78
Overhead plastic water tanks are manufactured by ___________ process
Answer
B. Rotomolding
79
The formation of polyurethane involves chemical reaction between
Answer
A. a di/poly isocyanate and a diol of polyol
80
Which of the following statements is correct?
Answer
C. UHMWPE is made up of extremely long chains of polyethylene, which all align in the same direction
81
Which among the following test is carried out as per ASTM D 256
Answer
B. Izod impact testing
82
As per is 532 : 2006 tension set of cycle tube shall not be more than
Answer
C. 15%
83
In tensile testing of a rubber sample using standard dumbbell specimen, the maximum load observed is 60 N. Find the ultimate tensile strength of the gague length of specimen = 200mm, thickness of specimen = 2mm and the wodth of specimen at narrow portion = 633
Answer
A. 5 N/mmÂČ
84
Expression for cure index (ÎtL) in a cure characteristics study using money viscometer with a large rotor is
Answer
A. Î
85
According to BIS speciïŹcation minimum mechanical stability time required for concentrated NR latex is
Answer
C. 475
86
In order to ïŹnd plasticity retention index samples are aged
Answer
A. For 30 minutes at 140ÂșC
87
Capacitance of a capacitor made only with two metallic sheets is increased from 2 F to 5F when the gap between is ïŹlled with a polymer. Find the dielectric constant of that polymer
Answer
B. 2.5
88
Which among the following has highest iodine adsorption number
Answer
B. SAF
89
Roll deïŹection is observed in calendars due to (i) The force that pulls calenders rolls apart is higher in middle and less at ends (ii) Rolls tend to bend under its own weight (iii) Uniformly distributed normal force from the compound
Answer
B. (i) only
90
In a three roll calender the ratio of speed of middle roll and bottom roll is 1:1.5. This calender can be used for
Answer
A. Frictioning
91
Compression ratio that can be used for rigid PVC extruder is
Answer
C. 2.5:1
92
Which method is used for the production of electric wires
Answer
B. Cross head extrusion
93
Sink mark defect in transfer molding can be eliminated by (i) Increasing transfer pressure (ii) Increasing charge weight (iii) Reducing mold temperature
Answer
D. (i), (ii) and (iii)
94
Which among the following gate is preferred for making solid block type injection molded articles
Answer
A. Tab gate
95
Rotors of banbury are
Answer
B. Non Intemeshing
96
In compounding of rubber using two roll mill, dispersive mixing can be improved by (i) Increasing shear rate (ii) Reducing gap between rolls (iii) homogenization
Answer
D. (i) and (ii)
97
Uniform thickness of extrusion blow molded articles are achieved by (i) Extruding parison with uniform thickness (ii) Applying high blowing pressure (iii) Parison programming
Answer
C. (iii) only
98
Forming temperature of polypropylene used for thermoforming is
Answer
B. 140-165ÂșC
99
Identify the combination of chemicals that can be used for RIM
Answer
C. Poly(propylene oxide) triol and methylene diphenyl diisocyanate
100
Sequence of addition of compounding ingredients in early oil addition method (i) Elastomer (ii) Liquid ingredients (iii) Dry ingredients
Answer
D. (i), (iii), (ii)
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