Practice Questions

Q59.Sum of oxidation states of bromine in bromic acid and perbromic acid is JEE Main 2023 (01 Feb Shift 1) JEE Main Previous Year Paper

Q60.Number of ambidentate ligands in a representative metal complex M ( en ) ( SCN ) is _________ . [en = 4 ethylenediamine]

Q60.A trisubstituted compound 'A', C10H12O2 gives neutral FeCl3 test positive. Treatment of compound 'A' with NaOH and CH3Br gives C11H14O2, with hydroiodic acid gives methyl iodide and with hot conc. NaOH gives a compound B, C10H12O2. Compound 'A' also decolorises alkaline KMnO4. The number of 𝜋 bond/s present in the compound 'A' is _____ .

Q60.A ( g ) →2 B ( g ) + C ( g ) is a first order reaction. The initial pressure of the system was found to be 800 mm Hg which increased to 1600 mm Hg after 10 min. The total pressure of the system after 30 min will be mm Hg. (Nearest integer)

Q60.The homoleptic and octahedral complex of Co2+ and H2O has ______ unpaired electron(s) in the t2g set of orbitals.

Q61.If the value of real number α > 0 for which x2 −5αx + 1 = 0 and x2 −αx −5 = 0 have a common real roots is 3 then β is equal to ________ √2β

Q65.The largest natural number n such that 3n divides 66! is _______

Q67.If 2n+1P n−1 : 2n−1P n = 11 : 21 , then n2 + n + 15 is equal to :

Q76.Let A = {0, 3, 4, 6, 7, 8, 9, 10} and R be the relation defined on A such that R{(x, y) ∈A × A : x −y is odd positive integer or x −y = 2}. The minimum number of elements that must be added to the relation R, so that it is a symmetric relation, is equal to _________ Q77. ⎡2 1 0 ⎤ Let 1 2 −1 . If |adj(adj(adj2A))| = (16)n , then n is equal to ⎣0 −1 2 ⎦ (1) 8 (2) 10 (3) 9 (4) 12 Q78. ⎡ √32 12 ⎤ 1 1 T a b Let P = , A = and Q = PAP . If P TQ2007 P = then 2a + b −3c −4d is equal √3 [0 1] [ c d ] ⎣−12 2 ⎦ to (1) 2004 (2) 2005 (3) 2007 (4) 2006

Q82.The coefficient of 𝑥18 in the expansion of 𝑥4 - is ____________ 𝑥3

Q85.The remainder on dividing 599 by 11 is _____ .

Q85.The number of elements in the set {n ∈N : 10 ≤n ≤100 and 3n −3 is a multiple of 7} is _______. JEE Main 2023 (15 Apr Shift 1) JEE Main Previous Year Paper

Q88.The number of elements in the set 𝑛∈ℤ: 𝑛2 - 10𝑛+ 19 < 6 is _______ .

Q88.The value of 8 𝜋∫0 sin𝑥2023 + cos𝑥2023𝑑𝑥 is ______. 3

Q88.Let →𝑎 and →𝑏 be two vector such that →𝑎= √14, →𝑏= √6 and →𝑎× →𝑏= √48. Then →𝑎· →𝑏 is equal to _____ . 𝑥- 1 𝑦+ 1 𝑧- 3

Q89.The value of 12 ∫0 𝑥2 - 3𝑥+ 2dx is ______ 𝑥- 2 𝑦+ 1 𝑧- 6 𝑥- 6 1 - 𝑦 𝑧+ 8

Q7. The efficiency of a Carnot's engine, working between steam point and ice point, will be (1) 26. 81% (2) 37. 81% (3) 47. 81% (4) 57. 81%

Q18.The activity of a radioactive material is 6. 4 × 10−4 curie. Its half life is 5 days. The activity will become 5 × 10−6 curie after (1) 7 days (2) 15 days (3) 25 days (4) 35 days JEE Main 2022 (27 Jul Shift 2) JEE Main Previous Year Paper

Q19.For a constant collector-emitter voltage of 8 V , the collector current of a transistor reached to the value of 6 mA from 4 mA , whereas base current changed from 20 μA to 25 μA value. If transistor is in active state, small signal current gain (current amplification factor) will be (1) 240 (2) 400 (3) 0. 0025 (4) 200

Q20.A square wave of the modulating signal is shown in the figure. The carrier wave is given by C(t) = 5 sin(8πt) Volt. The modulation index is (1) 0. 2 (2) 0. 1 (3) 0. 3 (4) 0. 4

Q21.A car is moving with speed of 150 km h-1 and after applying the brake it will move 27 m before it stops. If the same car is moving with a speed of one third the reported speed then it will stop after travelling _____ m distance.

Q21.For 𝑧= 𝑎2𝑥3𝑦 12, where '𝑎' is a constant. If percentage error in measurement of '𝑥' and '𝑦' are 4%and 12%, respectively, then the percentage error for '𝑧' will be _____ % .

Q21.If the projection of 2 ^𝑖+ 4 ^𝑗- 2 ^𝑘 on ^𝑖+ 2 ^𝑗+ 𝛼 ^𝑘 is zero. Then, the value of 𝛼 will be

Q21.A car covers AB distance with first one-third at velocity v1 m s−1 , second one-third at v2 m s−1 and last one- third at v3 m s−1 . If v3 = 3v1, v2 = 2v1 and v1 = 11 m s−1 , then the average velocity of the car is _____ m s−1 .

Q21.From the top of a tower, a ball is thrown vertically upward which reaches the ground in 6 s. A second ball thrown vertically downward from the same position with the same speed reaches the ground in 1. 5 s. A third JEE Main 2022 (24 Jun Shift 1) JEE Main Previous Year Paper ball released, from the rest from the same location, will reach the ground in _____ s.