Practice Questions

Q55.The values of conductivity of some materials at 298 .15 K in Sm−1 are 2 .1 × 103, 1 .0 × 10−16, 1 .2 × 10, 3 .91 , 1 .5 × 10−2, 1 × 10−7, 1 .0 × 103. The number of conductors among the materials is _____.

Q56.The amount of electricity in Coulomb required for the oxidation of 1 mol of H2O to O2 is ______ × 105C .

Q56.One Faraday of electricity liberates x × 10 – 1 gram atom of copper from copper sulphate, x is______.

Q56.Time required for 99.9% completion of a first order reaction is _______ times the time required for completion of 90% reaction.(nearest integer)

Q57.The osmotic pressure of a dilute solution is 7 × 105 Pa at 273 K. Osmotic pressure of the same solution at 283 K is _______ × 104 Nm−2 .(Nearest integer)

Q57.Molality of an aqueous solution of urea is 4.44 m. Mole fraction of urea in solution is x × 10−3 . Value of x is - (Integer answer)

Q58.In the reaction of potassium dichromate, potassium chloride and sulfuric acid (conc.), the oxidation state of the chromium in the product is + _______.

Q58.Number of oxygen atoms present in chemical formula of fuming sulphuric acid is ______.

Q59.Number of ambidentate ligands among the following is ______ NO−2 , SCN−, C2O2−4 , NH3, CN−, SO2−4 , H2O.

Q59.The rate of first order reaction is 0. 04 mol L−1 s−1 at 10 minutes and 0. 03 mol L−1 s−1 at 20 minutes after initiation. Half life of the reaction is ______ minutes. (Given log 2 = 0. 3010, log 3 = 0. 4771) Round off your answer to the nearest integer.

Q60.Oxidation state of Fe(Iron) in complex formed in Brown ring test.

Q60.The compound formed by the reaction of ethanal with semicarbazide contains _______ number of nitrogen atoms. ¯

Q60.The number of tripeptides formed by three different amino acids using each amino acid once is _______.

Q60.From the given list, the number of compounds with +4 oxidation state of Sulphur SO3, H2 SO3, SOCl2, SF4, BaSO4, H2 S2O7

Q60.From the vitamins 𝐴, 𝐵1, 𝐵6, 𝐵12, 𝐶, 𝐷, 𝐸 and 𝐾, the number vitamins that can be stored in our body is ______.

Q61.The sum of all possible values of θ ∈[−π, 2π], for which 1−2i1+i coscosθθ is purely imaginary, is equal (1) 3π (2) 2π (3) 5π (4) 4π

Q61.The area (in sq. units) of the region S = {z ∈C : |z −1| ≤2; (z + ¯z) + i(z −¯z) ≤2, Im(z) ≥0} is (1) 7π (2) 7π 3 4 (3) 17π (4) 3π 8 2

Q62.Let Sa denote the sum of first n terms an arithmetic progression. If S20 = 790 and S10 = 145, then S15−S5 is : JEE Main 2024 (30 Jan Shift 1) JEE Main Previous Year Paper (1) 395 (2) 390 (3) 405 (4) 410

Q83.Remainder when 643232 is divided by 9 is equal to _____.

Q85.Let A = {2, 3, 6, 7} and B = {4, 5, 6, 8}. Let R be a relation defined on A × B by (a1, b1)R (a2, b2) if and only if a1 + a2 = b1 + b2 . Then the number of elements in R is _________

Q86.Let the inverse trigonometric functions take principal values. The number of real solutions of the equation 2 sin−1 x + 3 cos−1 x = 2π5 , is _______

Q87.Let f(x) = 2x −x2, x ∈R. If m and n are respectively the number of points at which the curves y = f(x) and y = f ′(x) intersects the x−axis, then the value of m + n is

Q89.The least positive integral value of α, for which the angle between the vectors αˆi −2ˆj + 2ˆk and αˆi + 2αˆj −2ˆk is acute, is _____.

Q6. A 100 m long wire having cross-sectional area 6 . 25 × 10-4 m2 and Young's modulus is 1010 N m-2 is subjected to a load of 250 N, then the elongation in the wire will be : (1) 6 . 25 × 10-3 m (2) 4 × 10-4 m (3) 6 . 25 × 10-6 m (4) 4 × 10-3 m Q7. 1 g of a liquid is converted to vapour at 3 × 105 Pa pressure. If 10% of the heat supplied is used for increasing the volume by 1600 cm3 during this phase change, then the increase in internal energy in the process will be : (1) 4320 J (2) 432000 J (3) 4800 J (4) 4 . 32 × 108 J JEE Main 2023 (24 Jan Shift 1) JEE Main Previous Year Paper

Q7. ICM is moment of inertia of a circular disc about an axis (CM) passing through its center and perpendicular to the plane of disc. IAB is its moment of inertia about an axis AB perpendicular to plane and parallel to axis CM at a distance 2 R from center, where R is the radius of the disc. The ratio of IAB and ICM is x : 9. The value of x is 3 ______.