May, 2022Flame Institute

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Which of the following statements is not true about low density polyethene

a. Tough b. Hard c. Poor conductor of electricity d. Highly branched structure Ans. d (8)

A particle falls towards earth from infinity. It’s velocity on reaching the earth would be

(a) Infinity (b) √2 gR (c) 2√gR (d) Zero Answer: b (7)

The common acid used in the manufacture of rayon and plastics is

a. Methanoic acid b. Ethanoic acid c. Propanoic acid d. Butanoic acid Ans. b (10)

Given the polymers (i)Nylon 66; (ii) Buna-S; (iii) Polythene, arrange these in increasing order of their inter- molecular forces (lower to higher)

a. (i) > (ii) > (iii) b. (ii) > (iii) > (i) c. (ii) <(iii) <(i) d. (iii) <(i) <(ii) Ans. c (4)

Acetate rayon is prepared from

a. Acetic acid b. Glycerol c. Starch d. Cellulose Ans. d (9)

A body of mass m kg. starts falling from a point 2R above the Earth’s surface. Its kinetic energy when it has fallen to a point ‘R’ above the Earth’s surface [R-Radius of Earth, M-Mass of Earth, G-Gravitational Constant]

(a) 1/4 (GMm /R) (b) 1/6 ( (GMm /R) (c) 2/3 (GMm /R) (d) 1/3 (GMm /R) Answer: b (40)

123. The speed of a homogeneous solid sphere after rolling down an inclined plane of vertical height h, from rest without sliding, is

(a) √(10/7 gh) (b) √(gh) (c) √(6/5 gh) (d) √(4/3 gh) Ans. a (7)

A body is projected vertically upwards from the surface of a planet of radius R with a velocity equal to half the escape velocity for that planet. The maximum height attained by the body is

(a) R/3 (b) R/2 (c) R/4 (d) R/5 Answer: a (4)

Which of the following polymer has ester linkage

a. Nylon – 66 b. Nylon c. Terylene d. SBR Ans. c (7)

122. A hollow cylinder and a solid cylinder having the same mass and same diameter are released from rest simultaneously from the top of an inclined plane. Which will reach the bottom first

(a) The solid cylinder (b) The hollow cylinder (c) Both will reach the bottom together (d) The greater density Ans. a (7)

Which of the following is not polyamide

a. Nylon – 66 b.Protein c. Glyptal d. Nylon -6 Ans. c (7)

In some region, the gravitational field is zero. The gravitational potential in this region

(a) Must be variable (b) Must be constant (c) Cannot be zero (d) Must be zero Answer: b (10)

Trans- form of polyisoprene is

a. Guttapercha b. Hydrochloride rubber c. Buna – N d. Synthetic rubber Ans. a (6)

126. A solid cylinder of mass M and radius R rolls down an inclined plane without slipping. The speed of its centre of mass when it reaches the bottom is

(a) √(2gh) (b) √(4/3 gh) (c) √(3/4 gh) (d) √(4g/h) Ans. b (3)

Radius of orbit of satellite of earth is R. Its kinetic energy is proportional to

(a) 1/R (b) 1 /√R (c) R …

Which of the following is not true

a. In vulcanization the rubber becomes harder and stronger b. Natural rubber has ‘trans’ configuration at every double bond c. Buna- S is a co-polymer of butene and styrene d. Natural rubber is 1, 4- polymer of isoprene Ans. b …

The kinetic energy needed to project a body of mass m from the earth surface (radius R) to infinity is

(a) mgR/2 (b) 2 mgR (c) mgR (d) mgR/4 Answer: c (4)

which of the following polymers turns yellowish on exposure to sunlight

a. Polystyrene b. Nylon c. Polyethylene d. styrene butadiene resin Ans. d (9)

124. A solid cylinder rolls down an inclined plane from a height h. At any moment the ratio of rotational kinetic energy to the total kinetic energy would be

(a) 1 : 2 (b) 1 : 3 (c) 2 : 3 (d) 1 : 1 Ans. b (4)

The monomer of Nylon-6 is /are

Ans. b (12)

Energy required to move a body of mass m from an orbit of radius 2R to 3R is

(a) GMm/ 12R2 (b) GMm/ 3R2 (c) GMm / 8R (d) GMm / 6R Answer: d (6)

The monomer of the polymer

Ans. a (11)

which of the following is a polyamide

a. Teflon b. Nylon-66 c. Terylene d. Bakelite Ans. b (5)

121. A solid sphere (mass 2 M) and a thin hollow spherical shell (mass M) both of the same size, roll down an inclined plane, then

(a) Solid sphere will reach the bottom first (b) Hollow spherical shell will reach the bottom first (c) Both will reach at the same time (d) None of these Ans. a (34)

Nylon polymers are

a. Acidic b. Basic c. Amphoteric d. Neutral Ans. c (12)

Among cellulose , polyvinyl chloride, nylon and natural rubber, the polymer in which the intermolecular force of attraction is weakest in

a. Nylon b. Polyvinyl chloride c. Cellulose d. Natural rubber Ans. d (5)

119. Part of the tuning arrangement of a radio consists of a wheel which is acted on by two parallel constant forces as shown in the fig. If the wheel rotates just once, the work done will be about (diameter of the wheel = 0.05m)

(a) 0.062 J (b) 0.031 J (c) 0.015 J (d) 0.057 J Ans. b (31)

Which of the following intermolecular forces are present in ‘nylon – 66 ‘

a. Vander Waals b. Hydrogen bonding c. Dipole-dipole interaction d. None of these Ans. b (45)

120. A solid sphere, a hollow sphere and a ring are released from top of an inclined plane (frictionless) so that they slide down the plane. Then maximum acceleration down the plane is for (no rolling)

(a) Solid sphere (b) hollow sphere (c) Ring (d) All same Ans. d (23)

Which of the following organic compounds polymerizes to form the polyester Dacron

a. Terephthalic acid and ethylene glycol b. Benzoic acid and para HO – (C 6 H 4 ) – OH c. Propylene and para HO – (C 6 H 4 ) – OH d. Benzoic acid and ethanol Ans. a (10)

A body of mass m is placed on the earth’s surface. It is taken from the earth’s surface to a height h=3R . The change in gravitational potential energy of the body is

(a) 2/3 mgR (b) 3/4 mgR (c) mgR/2 (d) mgR/4 Answer: b (5)

Terylene is

a. An addition polymer with a benzene ring in every repeating unit b. a condensation polymer with a benzene ring in every repeating unit c. An addition polymer with two carbon atoms in every repeating unit d. a condensation polymer …

Complete hydrolysis of cellulose gives

a. D- fructose b. D- ribose c. D – glucose d. L – glucose Ans. c (7)

Celluloid is

a. A thermoplastic material obtained from caprolactam and urea b. A thermoplastic material obtained from nitrate and camphor c. A thermoplastic material obtained from urea and formaldehyde d. A thermoplastic material obtained from glycerol and phthalic anhydride Ans. b …