Practice Questions

Q28.A radio active material is reduced to 1 of its original amount in 3 days. If 8 × 10−3 kg of the material is left 8 after 5 days the initial amount of the material is (1) 40 g (2) 32 g (3) 64 g (4) 256 g

Q29.The logic gate equivalent to the given circuit diagram is : JEE Main 2023 (24 Jan Shift 2) JEE Main Previous Year Paper (1) OR (2) NAND (3) NOR (4) AND

Q29.The energy levels of an atom is shown is figure. Which one of these transitions will result in the emission of a photon of wavelength 124. 1 nm? Given ( h = 6. 62 × 10–34 J s) JEE Main 2023 (25 Jan Shift 2) JEE Main Previous Year Paper (1) B (2) A (3) C (4) D

Q29.The output Y for the inputs A and B of circuit is given by Truth table of the shown circuit is : (1) A B Y (2) A B Y ⎡ 0 0 1 ⎤ ⎡ 0 0 1 ⎤ 0 1 1 0 1 0 1 0 1 1 0 0 1 1 0 1 1 1 ⎣ ⎦ ⎣ ⎦ (3) A B Y (4) A B Y ⎡ 0 0 0 ⎤ ⎡ 0 0 0 ⎤ 0 1 1 0 1 1 1 0 1 1 0 1 1 1 1 1 1 0 ⎣ ⎦ ⎣ ⎦

Q29.The logic operations performed by the given digital circuit is equivalent to: (1) NOR (2) AND (3) OR (4) NAND

Q29.For a given transistor amplifier circuit in CE configuration VCC = 1 V, RC = 1 kΩ, Rb = 100 kΩ and β = 100 . Value of base current Ib is JEE Main 2023 (08 Apr Shift 2) JEE Main Previous Year Paper (1) Ib = 1. 0 μA (2) Ib = 0. 1 μA (3) Ib = 100 μA (4) Ib = 10 μA

Q30.A TV transmitting antenna is 98 m high and the receiving antenna is at the ground level. If the radius of the earth is 6400 km, the surface area covered by the transmitting antenna is approximately: JEE Main 2023 (08 Apr Shift 1) JEE Main Previous Year Paper (1) 1240 km2 (2) 3942 km2 (3) 4868 km2 (4) 1549 km2 Q31. 0. 5 g of an organic compound (X) with 60% carbon will produce ×10−1 g of CO2 on complete combustion.

Q30.The amplitude of 15 sin(1000 πt) is modulated by 10 sin(4 πt) signal. The amplitude modulated signal contains frequencies of A. 500 Hz B. 2 Hz C. 250 Hz D. 498 Hz E. 502 Hz Choose the correct answer from the options given below JEE Main 2023 (12 Apr Shift 1) JEE Main Previous Year Paper (1) A and B only (2) A and C only (3) A and D only (4) A, D and E only

Q30.The power radiated from a linear antenna of length l is proportional to (Given, λ = Wavelength of wave): (1) λ l (2) ( λl ) 2 (3) l (4) l2 λ2 λ

Q31.If the radius of the first orbit of hydrogen atom is a0 , then de Broglie’s wavelength of electron in 3rd orbit is (1) πa0 (2) πa0 6 3 (3) 6πa0 (4) 3πa0

Q31.The radius of the 2nd orbit of Li2+ is x . The expected radius of the 3rd orbit of Be3+ is (1) 9 4 x (2) 94 x (3) 27 16 x (4) 2716 x JEE Main 2023 (25 Jan Shift 1) JEE Main Previous Year Paper

Q31.The wave function (Ψ) of 2 s is given by 1/2 − Ψ2s = a0 1 ( a01 ) (2 r )e−r/2a0 2√2π At r = r0 , radial node is formed. Thus, r0 in terms of a0 (1) r0 = a0 (2) r0 = 4a0 (3) r0 = a02 (4) r0 = 2a0

Q31.When a hydrocarbon A undergoes complete combustion it requires 11 equivalents of oxygen and produces 4 equivalents of water. What is the molecular formula of A? (1) C11H8 (2) C11H4 (3) C5H8 (4) C9H8

Q31.For a concentrated solution of a weak electrolyte (Keq = equilibrium constant) A2B3 of concentration ‘C’, the degree of dissociation ‘α’ is (1) Keq 15 (2) Keq 15 5c4 108c4 (3) Keq 15 (4) Keq 15 25c2 6c5 JEE Main 2023 (06 Apr Shift 1) JEE Main Previous Year Paper

Q31.The shortest wavelength of hydrogen atom in Lyman series is λ. The longest wavelength in Balmer series of He+ is (1) 5 (2) 9λ 9λ 5 (3) 36λ (4) 5λ 5 9

Q31.A metal chloride contains 55. 0% of chlorine by weight. 100 mL vapours of the metal chloride at STP weigh 0. 57 g . The molecular formula of the metal chloride is (Given: Atomic mass of chlorine is 35. 5 u ) (1) MCl4 (2) MCl3 (3) MCl2 (4) MCl

Q31.Which transition in the hydrogen spectrum would have the same wavelength as the Balmer type transition from n = 4 to n = 2 of He+spectrum (1) n = 2 to n = 1 (2) n = 1 to n = 3 (3) n = 1 to n = 2 (4) n = 3 to n = 4

Q32.What is the number of unpaired electron(s) in the highest occupied molecular orbital of the following species : N2, N +2 , O2, O+2 ? (1) 0, 1, 2, 1 (2) 2, 1, 2, 1 (3) 0, 1, 0, 1 (4) 2, 1, 0, 1

Q32.Which one of the following elements will remain as liquid inside pure boiling water? JEE Main 2023 (06 Apr Shift 2) JEE Main Previous Year Paper (1) Ga (2) Br (3) Li (4) Cs

Q32.Match Lis-I with List-II. List-1 List-II Hexamethylenediamine A. Weak intermolecular forces of attraction I. + adipic acid B. Hydrogen bonding II. AlEt3 + TiCl4 C. Heavily branched polymer III. 2 - chloro - 1, 3 - butadiene D. High density polymer IV. Phenol + formaldehyde Choose the correct answer from the options given below (1) A-IV, B-II, C-III, D-I (2) A-IV, B-I, C-III, D-II (3) A-II, B-IV, C-I, D-III (4) A-III, B-I, C-IV, D-II

Q32.The pair from the following pairs having both compounds with net non-zero dipole moment is JEE Main 2023 (10 Apr Shift 1) JEE Main Previous Year Paper (1) 1, 4-Dichlorobenzene, 1, 3-Dichlorobenzene (2) cis-butene, trans-butene (3) CH2Cl2, CHCl3 (4) Benzene, anisidine

Q32.Match List-I with List-II List-I List-II A 16 g of CH4 ( g ) I Weighs 28g B 1 g of H2 ( g ) II 60 . 2 × 1023 electrons C 1 mole of N2 ( g ) III Weighs 32g D 0 . 5 mol of SO2 ( g ) IV Occupies11 . 4 L volume at STP Choose the correct answer from the options given below: JEE Main 2023 (10 Apr Shift 2) JEE Main Previous Year Paper (1) A-II, B-III, C-IV, D-I (2) A-II, B-IV, C-I, D-III (3) A-I, B-III, C-II, D-IV (4) A-II, B-IV, C-III, D-I

Q32.Given below are two statements : one is labelled as Assertion A and the other is labelled as Reason R : Assertion A: In the photoelectric effect, the electrons are ejected from the metal surface as soon as the beam of light of frequency greater than threshold frequency strikes the surface. Reason R : When the photon of any energy strikes an electron in the atom, transfer of energy from the photon to the electron takes place. In the light of the above statements, choose the most appropriate answer from the options given below : (1) Both A and R are correct and R is the correct (2) A is correct but R is not correct explanation of A (3) Both A and R are correct but R is NOT the (4) A is not correct but R is correct correct explanation of A JEE Main 2023 (11 Apr Shift 1) JEE Main Previous Year Paper

Q32.Decreasing order of the hydrogen bonding in following forms of water is correctly represented by A. Liquid water B. Ice C. Impure water (1) A = B > C (2) B > A > C (3) C > B > A (4) A > B > C

Q32.For OF2 molecule consider the following: (A) Number of lone pairs on oxygen is 2. (B) FOF angle is less than 104 . 5°. (C) Oxidation state of O is -2. (D) Molecule is bent 'V' shaped. (E) Molecular geometry is linear. Correct options are: (1) C, D, E only (2) B, E, A only (3) A, C, D only (4) A, B, D only