JEE Full Syllabus MCQs Set B

Question. In a stack of three polarizing sheets the first and third are crossed while the middle one has its axis at 45° to the axes of the other two. The fraction of the intensity of an incident unpolarized beam of light that is transmitted by the stack is
(a) 1/8
(b) 1/3
(c) 1/2
(d) 1/4

Answer: A

Question. A plastic circular disc of radius R is placed on a thin oil film, spread over a flat horizontal surface. The torque required to spin the disc about its central vertical axis with a constant angular velocity is proportional to :-
(a) R4
(b) R2
(c) R3
(d) R6

Answer: A

Question. A plano-convex lens, when silvered at its plane surface is equivalent to a concave mirror of focal length 28 cm. When its curved surface is silvered and the plane surface not silvered, it is equivalent to a concave mirror of focal length 10 cm, then the refractive index of the material of the lens is:-
(a) 14/9
(b) 17/9
(c) 9/14
(d) None

Answer: A

Question. A given initial mass of KClO3 on 50% decomposition produces 67.2 litre oxygen gas at 0ºC and 1 atm. The other product of decomposition is KCl. The initial mass of KClO3 (in gm) taken is.
(a) 490
(b) 122.5
(c) 245
(d) None of these

Answer: A

Question. At what temperature will be the molar kinetic energy of 0.3 mole of He will be the same as molar kinetic energy of 0.4 mol of Argon gas at 400K
(a) 400 K
(b) 500 K
(c) 700 K
(d) 700 K

Answer: A

Question. Which of the following solutions is expected to show positive deviations from Raoult's law ?
(a) Ethanol – Hexane
(b) Acetone – Chloroform
(c) Hydrochloric acid – Water
(d) Pyridine – Formic acid

Answer: A

Question. Which of the following statements regarding sols is not correct.
(a) On prolong dialysis, colloids become stable.
(b) An emulsion can be broken both by heating as well as freezing.
(c) In a reaction, catalyst may change qualitatively as well as physically.
(d) Brownian movement stablises sols.

Answer: A

Question. Identify the correct order.
(a) CsCl > RbCl > KCl > NaCl > LiCl (% ionic character)
(b) CsCl < RbCl < KCl < NaCl < LiCl (m.p)
(c) CsCl < RbCl < KCl < NaCl < LiCl (Solubility in water)
(d) CsCl > RbCl > KCl > NaCl > LiCl (Lattice Energy)

Answer: A

Question. When copper reacts with hot conc. H2SO4 gives ?
(a) SO2
(b) H2
(c) O2
(d) None of these

Answer: C

Question. Which of the following s-block element forms blue colour with liquid NH3
(a) K
(b) Be
(c) Mg
(d) All of these

Answer: A

Question. Tin reacts with dilute nitric acid and produces
(a) NH4NO3
(b) NO2
(c) NO
(d) N2

Answer: C

Question. Anti Morkovnikov's addition of HBr to propene in presence of peroxide follow :
(a) Free radical mechanism
(b) Ionic mechanism with carbocation as intermediate
(c) Ionic mechanism with carbanion as intermediate
(d) Electrophilic addition with carbene as intermediate

Answer: A

Question. Which of the following carbohydrate can not be reduce by Tollen's reagent
(a) Sucrose
(b) Maltose
(c) Lactose
(d) D-Glucose

Answer: A

Question. In which of the following amino acid 2°-amino group is present
(a) Proline
(b) Phenyl alanine
(c) Glutamine
(d) Glycine

Answer: A

Question. Which of the following is not condensation polymer :
(a) PVC
(b) Glyptal
(c) Terylene
(d) Nylon-66

Answer: A

Question. Which of the following aromatic compound is most reactive towards electrophilic addition reaction
(a) Methoxy benzene
(b) Benzene
(c) Benzaldehyde
(d) Toluene

Answer: B

Question. A determinant |A| of order 3 x 3 is formed using the numbers from the set {0, 1, 2, 3}, then the difference of maximum and minimum value of this determinant is -
(a) 108
(b) 54
(c) 27
(d) 8

Answer: D

Question. If (1 + i) (1 + 2 i) (1 + 3 i) ...... (1 + n i) = x + iy, then value of 2, 5, 10 ..... (1 + n2) is:
(a) x2 + y2
(b) x + y
(c) x2 - y2
(d) x - y

Answer: A

Question. The cubic equation x3 – 6x2 – 15x + k = 0 will have one real and two complex roots only if k satisfies
(a) k > 100
(b) k < 0
(c) –8 < k < 100
(d) None of these

Answer: A

Question. Let ƒ (x) be differentiable function such that ƒ (x) and ƒ '(x) have opposite signs every where, then -
(a) |ƒ (x)| is decreasing function
(b) ƒ (x) is decreasing function
(c) ƒ (x) is an increasing function
(d) |ƒ (x)| is increasing function

Answer: A

Question. There are 6 chocolates of Nestle, 8 of Cadburry, 10 of Perks and 9 of Munch. The number of ways in which a child can buy 7 chocolates, is
(a) 119
(b) 120
(c) 83
(d) 116

Answer: A

Question. If a2 – b2 = c, where a, b, c are prime numbers then a is -
(a) 3
(b) 7
(c) 5
(d) 2

Answer: A

Question. The variance of 20 observation is 5. If each observation is multiplied by 2, then the new variance of the resulting observations, is
(a) 20
(b) 40
(c) 10
(d) 5

Answer: A