GATE 2018 Paper with Answer Keys for Polymer Science & Engineering (XE–F)
Q.1 Which one of the following polymers occurs naturally?
(A) Bakelite
(B) Teflon
(C) Cellulose
(D) Perspex
Ans:- C
Q.2 T he order of average molecular weights of a polymer is
(A) $latex M_z>M_w>M_v>M_n$
(B) $latex M_w>M_z>M_n>M_v$
(C) $latex M_n>M_w>M_v>M_z$
(D) $latex M_z>M_v>M_n>M_w$
Ans:- A
Q.3 Rubbers are a class of polymer known for
(A) High intermolecular forces
(B) High Tg polymers
(C) Crystalline polymers
(D) Low intermolecular forces
Ans:-D
Q.4 Nylon 6 is manufactured from
(A) Sebacic acid and hexamethylene diamine
(B) Caprolactam
(C) Adipic acid and hexamethylene diamine
(D) Caprolactone
Ans:- B
Q.5 Storage modulus and tan δ of a polymer are experimentally measured by
(A) Differential scanning calorimetry
(B) Thermogravimetric analysis
(C) Thermomechanical analysis
(D) Dynamic mechanical thermal analysis
Ans:- D
Q.6 A plastic bucket is manufactured by
(A) Compression moulding
(B) Injection moulding
(C) Extrusion
(D) Blow moulding
Ans:- B
Q.7 The monomers, A and B with reactivity ratios rA and rB, form alternate co-polymers when,
(A) rA = rB = 0
(B) rA = rB = 1
(C) rA > 1 ,rB > 1
(D) rA <1 , rB < 1
Ans:- A
Q.8 T he degree of polymerization of a poly(methyl methacrylate) sample having number average molecular weight of 1,50,000 g/mol is___________.
(C = 12, H = 1, O = 16 g/mol).
Ans:- 1500.00 to 1500.00
Q.9 If the heat of fusion of 100 % crystalline polyethylene is 290 mJ/mg, a sample of polyethylene with heat of fusion of 141 mJ/mg will have_______ % crystallinity.
Ans:- 48.52 to 48.72
Q.10 Match the following:
(A) P-3; Q-1; R-2; S-1
(B) P-2; Q-3; R-1; S-4
(C) P-4; Q-3; R-1; S-2
(D) P-2; Q-3; R-4; S-1
Ans:- D
Q.11 Match the following:
(A) P-4; Q-3; R-2; S-1
(B) P-2; Q-3; R-4; S-1
(C) P-4; Q-1; R-2; S-3
(D) P-3; Q-4; R-2; S-1
Ans:- A
Q.12 Flexible PVC tubes are used for watering. If some organic solvents are passed through this tube, it becomes stiff. This is due to the fact that the organic solvents
(A) plasticize PVC and raise Tg
(B) remove plasticizer and raise Tg
(C) remove plasticizer and lower Tg
(D) react with PVC and increase Tg
Ans:- B
Q.13 Match the following:
(A) P-3; Q-1; R-4; S-2
(B) P-4; Q-3; R-2; S-1
(C) P-2; Q-3; R-4; S-1
(D) P-4; Q-3; R-1; S-2
Ans:- D
Q.14 Match the following:
(A) P-4; Q-1; R-2; S-3
(B) P-4; Q-3; R-2; S-1
(C) P-3; Q-4; R-2; S-1
(D) P-2; Q-4; R-1; S-3
Ans:- B
Q.15 A plot of strain (%) versus time of a polymer is given below. Based on this plot and the properties as mentioned below, find out the correct combination.
1 = Viscoelastic deformation; 2 = Elastic deformation
3 = Viscoelastic recovery; 4 = Elastic recovery
(A) P-1; Q-4; R-2; S-3;
(B) P-2; Q-3; R-4; S-1
(C) P-3; Q-1; R-2; S-4
(D) P-2; Q-1; R-4; S-3
Ans:- D
Q.16 T he plot shows apparent viscosity versus shear rate of Newtonian, Dilatent and Pseudoplastic fluids. Based on this plot and the fluid behaviour as mentioned below, find out the correct combination.
1 = Dilatent fluid; 2 = Newtonian fluid, 3 = Pseudoplastic fluid
(A) P-1; Q-2; R-3
(B) P-3; Q-1; R-2
(C) P-2; Q-3; R-1
(D) P-2; Q-3; Q-1
Ans:- C
Q.17 P lot of the modulus versus temperature of different types of polymers is given below.Based on this plot and the nature of the polymers as mentioned below, find out the correct combination.
1 = An amorphous polymer of high molecular weight having entanglements
2 = An amorphous polymer of moderate molecular weight
3 = Highly crosslinked polymer
4 = Semi-crystalline polymer
(A) P-2; Q-1; R-3; S-4
(B) P-1; Q-2; R-3; S-4
(C) P-2; Q-1; R-4; S-3
(D) P-1; Q-3; R-4; S-2
Ans:- C
Q.18 The Tg of homopolymers of A and B are +100oC and -70 oC respectively. The Tg of a random copolymer of A and B having 40 wt% A and 60 wt% B is _oC.
Ans:- ‐25.00 to ‐24.50
Q.19 T he number average molecular weight of a polymer prepared from HO(CH2)14 COOH is 24,000 g/mol. The conversion of the monomer required to reach the above molecular weight is__________%.
(C = 12, H = 1, O = 16 g/mol).
Ans:- 98.80 to 99.10
Q.20 Glass fibers in nylon provide reinforcement. The modulus of elasticity for each component of the composite is; Eglass = 10.5 x 106 psi; Enylon = 0.4 x 106 psi. If the nylon contains 30 vol % E-glass, the fraction of the applied force is carried by the glass fiber is__________.
(Assume that both glass fiber and nylon have equal strain).
Ans:- 0.90 to 0.93
Q.21 The solubility parameter of a polymer having cohesive energy density (Ecoh )43870 J/mol and molar volume (V) 136 cm3 /mol is _(J/cm3 )1/2.
Ans:- 17.91 to 18.00
Q.22 T he heat of polymerization of styrene is 20 Kcal/mol. Heat of 5 x 105 Kcal will be released on polymerization of __ Kg of styrene (C = 12 and H = 1 g/mol).
Ans:- 2600 to 2600