Practice Questions

Q74.Among the following cations, the number of cations which will give characteristic precipitate in their identification tests with K4 [Fe(CN)6] is _____. Cu2+, Fe3+, Ba2+, Ca2+, NH+4 , Mg2+, Zn2+

Q74.The possible number of stereoisomers for 5-phenylpent-4-en-2-ol is … …

Q74.Niobium ( Nb ) and ruthenium (Ru) have " x " and " y " number of electrons in their respective 4 d orbitals. The value of x + y is ______ -.

Q75.Consider the following sequence of reactions. Total number of sp3 hybridised carbon atoms in the major product C formed is________ 2025 (23 Jan Shift 2) JEE Main Previous Year Paper

Q75.If A2B is 30% ionised in an aqueous solution, then the value of van't Hoff factor (i) is ______ ×10−1 . 2025 (29 Jan Shift 1) JEE Main Previous Year Paper

Q75.Consider the following sequence of reactions to produce major product (A) Molar mass of product (A) is gmol−1 . (Given molar mass in gmol−1 of C : 12, H : 1, O : 16, Br : 80, N : 14, P : 31 ) 2025 (23 Jan Shift 1) JEE Main Previous Year Paper

Q75.Given below is the plot of the molar conductivity vs √ concentration for KCl in aqueous solution. If, for the higher concentration of KCl solution, the resistance of the conductivity cell is 100Ω, then the resistance of the same cell with the dilute solution is ' x ' Ω The value of x is __________ (Nearest integer) 2025 (28 Jan Shift 1) JEE Main Previous Year Paper

Q75.Standard entropies of X2, Y2 and XY5 are 70,50 and 110 J K−1 mol−1 respectively. The temperature in Kelvin at which the reaction 1 2 X2 + 52 Y2 ⇌XY5ΔHΘ = −35 kJ mol−1 will be at equilibrium is_______. (Nearest integer) 2025 (24 Jan Shift 1) JEE Main Previous Year Paper

Q75.The spin only magnetic moment ( μ ) value (B.M.) of the compound with strongest oxidising power among Mn2O3, TiO and VO is ____ B.M. (Nearest integer). 2025 (28 Jan Shift 2) JEE Main Previous Year Paper

Q75.In Carius method for estimation of halogens, 180 mg of an organic compound produced 143.5 mg of AgCl . The percentage composition of chlorine in the compound is _______ \%. (Given : molar mass in gmol−1 of Ag : 108, Cl : 35.5 ) 2025 (22 Jan Shift 1) JEE Main Previous Year Paper

Q75.The hydrocarbon (X) with molar mass 80 g mol−1 and 90% carbon has … … degree of unsaturation. 2025 (24 Jan Shift 2) JEE Main Previous Year Paper

Q1. If mass is written as 𝑚= 𝑘𝑐𝑃𝐺-1 / 2 ℎ1 / 2, then the value of 𝑃 will be : (Constants have their usual meaning with 𝑘 a dimensionless constant) 1 1 (1) (2) 2 3 (3) 2 (4) -1 3

Q1. A particle moves in x −y plane under the influence of a force →F such that its linear momentum is →p(t) = ^i cos(kt) −^j sin(kt). If k is constant, the angle between →F and →p will be : (1) π (2) π 4 6 (3) π (4) π 2 3

Q1. In an experiment to measure focal length (f) of convex lens, the least counts of the measuring scales for the position of object (u) and for the position of image (v) are Δu and Δv , respectively. The error in the measurement of the focal length of the convex lens will be: (1) 2f [ Δuu + Δvv ] (2) Δuu + Δvv (3) f 2 [ Δuu2 + Δvv2 ] (4) f [ Δuu + Δvv ]

Q1. To find the spring constant (k) of a spring experimentally, a student commits 2% positive error in the measurement of time and 1% negative error in measurement of mass. The percentage error in determining value of k is : (1) 5% (2) 1% (3) 3% (4) 4%

Q1. Given below are two statements : Statement (I) : Dimensions of specific heat is [L2 T−2 K−1]. Statement (II) : Dimensions of gas constant is [ML2 T−1 K−1]. In the light of the above statements, choose the most appropriate answer from the options given below. (1) Both statement (I) and statement (II) are correct (2) Statement (I) is correct but statement (II) is incorrect (3) Both statement (I) and statement (II) are incorrect (4) Statement (I) is incorrect but statement (II) is Statement (I) is incorrect but statement (II) is correct correct

Q1. The radius 𝑟, length 𝑙 and resistance 𝑅 of a metal wire was measured in the laboratory as 𝑟= 0 .35 ± 0 .05 cm, 𝑅= 100 ± 10 ohm, 𝑙= 15 ± 0 .2 cm The percentage error in resistivity of the material of the wire is : (1) 25 . 6% (2) 39 .9 % (3) 37 . 3% (4) 35 .6 %

Q2. LIST I LIST II A. Torque I. [M 1L1T −2A−2] Match List I with List II B. Magnetic field II. [L2A1] Choose the correct C. Magnetic moment III. [M 1T −2A−1] D. Permeability of free space IV. [M 1L2T −2] answer from the options given below: (1) A-III, B-I, C-II, D-IV (2) A-IV, B-II, C-III, D-I (3) A-IV, B-III, C-II, D-I (4) A-I, B-III, C-II, D-IV

Q2. Consider two physical quantities 𝐴 and 𝐵 related to each other as 𝐸= 𝐵−𝑥2 where 𝐸, 𝑥 and 𝑡 have dimensions 𝐴𝑡 of energy, length and time respectively. The dimension of 𝐴𝐵 is (1) 𝐿−2𝑀1𝑇0 (2) 𝐿2𝑀-1𝑇1 (3) 𝐿−2𝑀-1𝑇1 (4) 𝐿0𝑀-1𝑇1

Q2. A body projected vertically upwards with a certain speed from the top of a tower reaches the ground in t1 . If it is projected vertically downwards from the same point with the same speed, it reaches the ground in t2 . Time required to reach the ground, if it is dropped from the top of the tower, is : (1) √t1t2 (2) √t1 + t2 (3) √t1 −t2 (4) √t1t2

Q2. Projectiles 𝐴 and 𝐵 are thrown at angles of 45° and 60° with vertical respectively from top of a 400 m high tower. If their times of flight are same, the ratio of their speeds of projection 𝑣𝐴: 𝑣𝐵 is: (1) 1: √3 (2) √2: 1 (3) 1: 2 (4) 1: √2

Q2. Two cars are travelling towards each other at speed of 20 m s−1 each. When the cars are 300 m apart, both the drivers apply brakes and the cars retard at the rate of 2 m s−2 . The distance between them when they come to rest is : (1) 200 m (2) 100 m (3) 50 m (4) 25 m

Q2. A bullet is fired into a fixed target looses one third of its velocity after travelling 4 cm. It penetrates further 𝐷× 10-3 m before coming to rest. The value of 𝐷 is : (1) 32 (2) 5 (3) 3 (4) 4

Q2. A body starts moving from rest with constant acceleration covers displacement S1 in first (p −1) seconds and S2 in first p seconds. The displacement S1 + S2 will be made in time : (1) (2p + 1) s (2) √(2p2 −2p + 1) s (3) (2p −1) s (4) (2p2 −2p + 1) s

Q2. A particle of mass m projected with a velocity u making an angle of 30° with the horizontal. The magnitude of angular momentum of the projectile about the point of projection when the particle is at its maximum height h is : (1) √3 mu3 (2) √3 mu2 16 g 2 g (3) mu3 (4) zero √2g