GATE XE topic:engineering PYQs & Answers — Page 33

Questions 321–330 of 1772. Imported answers require independent review unless marked reviewed.

Which option(s) correctly match(es) the Class of additives used during polymer compounding with the corresponding Chemicals?

Class of additives: P — Antioxidant; Q — Flame retardant; R — Plasticizer; S — Colorant.

Chemicals: 1 — Phthalocyanine; 2 — Di(2-ethylhexyl) phthalate; 3 — Tricresyl phosphate; 4 — Phenyl β-naphthyl amine

Your answerSelect all correct options. You can choose more than one.

P-4; Q-3; R-2; S-1

P-4; Q-3; R-3; S-1

P-1; Q-2; R-4; S-2

P-2; Q-3; R-1; S-2

You can attempt this question now. Sign in to view the answer key, explanations and discussion.Log in to check answer

In a set of copolymerization reactions, the following monomer reactivity ratios (r1 and r2) were found for different cases:

Case I: r1 = 0.1, r2 = 10 Case II: r1 = 0.03, r2 = 0.02 Case III: r1 = 3.4, r2 = 5.6 Case IV: r1 = 51, r2 = 0.01

Which option(s) correctly identify/identifies the type of polymerization corresponding to each Case?

Your answerSelect all correct options. You can choose more than one.

I - Ideal copolymerization

II - Azeotropic copolymerization

III - Block copolymerization

IV - Alternating copolymerization

You can attempt this question now. Sign in to view the answer key, explanations and discussion.Log in to check answer

The crystallization of a polymer can only proceed in a temperature range limited to glass transition temperature (T_g) on the lower side, the equilibrium melting point (T_m^o) on the higher side. Around T_g, the mobility of the polymer chains is lower, while in the proximity of T_m^o, crystallization is inhibited.

In a miscible polymer blend with only one component being crystalline, which option(s) correctly match(es) the Temperature conditions with Events?

Temperature conditions: P — The T_g of the amorphous component is lower than the crystallizable one; Q — The T_g of the amorphous component is higher than the crystallizable one; R — The blend T_g is higher than the T_m^o of the crystallizable one.

Events: 1 — The temperature range over which crystallization can occur becomes smaller; 2 — Crystallization is inhibited; 3 — The crystallization envelope (T_m^o − T_g) is widened; 4 — Crystallization is favored.

Your answerSelect all correct options. You can choose more than one.

P-3; Q-2; R-4

P-3; Q-1; R-2

P-4; Q-1; R-3

P-4; Q-1; R-2

You can attempt this question now. Sign in to view the answer key, explanations and discussion.Log in to check answer

The heat of polymerization of ethylene is 25 Kcal/mol. The amount of heat generated during the polymerization of 5.6 Kg polyethylene is ______ Kcal. (Round off to the nearest integer)

You can attempt this question now. Sign in to view the answer key, explanations and discussion.Log in to check answer

The density of an amorphous polymer is 0.77 g cm⁻³ and that of its crystalline counterpart is 0.9 g cm⁻³. The density of a semi-crystalline sample of this polymer is found to be 0.88 g cm⁻³.

The degree of crystallinity (on weight basis) of this semi-crystalline sample is ________. (Round off to two decimal places)

You can attempt this question now. Sign in to view the answer key, explanations and discussion.Log in to check answer

Titration was used to determine the molar mass of two linear monodisperse polymers A and B. Both the polymers possess the same repeat unit and contain acid end-groups. First, 10 g of polymer A was titrated with 5 mL of a 0.1 M alkali solution. In a separate experiment, 5 g of polymer B was titrated with 5 mL of a 0.1 M alkali solution. All of the alkali solution reacted with the acid end-groups present in both polymer A and polymer B.

The ratio of the molar mass of A to the molar mass of B is ________ . (Round off to one decimal place)

You can attempt this question now. Sign in to view the answer key, explanations and discussion.Log in to check answer

A unidirectional composite of a resin is prepared with continuous fibers, where the volume fraction of the fiber in the composite is 0.7. Assume that the resin has a modulus of 9 GPa and the fiber has a modulus of 90 GPa. A sample of this composite, possessing a breadth of 4 mm and a thickness of 1 mm, is subjected to a uniaxial tensile test along the direction of the fiber.

Corresponding to a strain of 0.5 %, the force applied on the sample is ________ N. (Round off to the nearest integer)

You can attempt this question now. Sign in to view the answer key, explanations and discussion.Log in to check answer

A rubber contains 70 wt% butadiene (molar mass = 54 g/mol), 20 wt% isoprene (molar mass = 68 g/mol), 5 wt% sulfur and 5 wt% carbon black. Assume that all the sulfur is present in crosslinks.

If each sulfide crosslink contains an average of two sulfur atoms, the percentage of possible crosslinks that are joined by vulcanization is ________%. (Round off to one decimal place)

You can attempt this question now. Sign in to view the answer key, explanations and discussion.Log in to check answer

Which of the following contains the phytonutrient allicin?

Your answerChoose one option.

Grape

Cauliflower

Garlic

Chili

You can attempt this question now. Sign in to view the answer key, explanations and discussion.Log in to check answer

Which mold is responsible for the characteristic blue marbling in blue-veined cheese?

Your answerChoose one option.

Rhizopus oryzae

Penicillium roqueforti

Aspergillus niger

Penicillium camemberti

You can attempt this question now. Sign in to view the answer key, explanations and discussion.Log in to check answer

GATE XE topic:engineering PYQs

Question 124

Question 125

Question 126

Question 127

Question 128

Question 129

Question 130

Question 131

Question 132

Question 133