Practice Questions

Q20.Conductivity of a photodiode starts changing only if the wavelength of incident light is less than 660 nm . X The band gap of photodiode is found to be eV . The value of X is: 8 (Given h = 6 . 6 × 10-34 J s, e = 1 . 6 × 10-19 C) (1) 15 (2) 11 (3) 13 (4) 21

Q20.A vernier callipers has 20 divisions on the vernier scale, which coincides with 19th division on the main scale. The least count of the instrument is 0.1 mm. One main scale division is equal to _____ mm . (1) 0.5 (2) 2 (3) 5 (4) 1

Q20. In the truth table of the above circuit the value of X and Y are : (1) 0,0 (2) 1,1 (3) 1,0 (4) 0,1

Q20.If 50 Vernier divisions are equal to 49 main scale divisions of a travelling microscope and one smallest reading of main scale is 0 . 5 mm the Vernier constant of travelling microscope is: (1) 0 . 1 mm (2) 0 . 1 cm (3) 0 . 01 cm (4) 0 . 01 mm → →

Q20.Following gates section is connected in a complete suitable circuit. For which of the following combination, bulb will glow (ON) : (1) A = 0, B = 0, C = 0, D = 1 (2) A = 0, B = 1, C = 1, D = 1 (3) A = 1, B = 0, C = 0, D = 0 (4) A = 1, B = 1, C = 1, D = 0

Q20.In the given circuit, the breakdown voltage of the Zener diode is 3. 0 V. What is the value of Iz ? JEE Main 2024 (29 Jan Shift 1) JEE Main Previous Year Paper (1) 3. 3 mA (2) 5. 5 mA (3) 10 mA (4) 7 mA

Q20.The truth table for this given circuit is: JEE Main 2024 (29 Jan Shift 2) JEE Main Previous Year Paper (1) (2) (3) (4)

Q20.In a vernier calliper, when both jaws touch each other, zero of the vernier scale shifts towards left and its 4th division coincides exactly with a certain division on main scale. If 50 vernier scale divisions equal to 49 main scale divisions and zero error in the instrument is 0.04 mm then how many main scale divisions are there in 1 cm ? (1) 10 (2) 5 (3) 20 (4) 40

Q20.There are 100 divisions on the circular scale of a screw gauge of pitch 1 mm . With no measuring quantity in between the jaws, the zero of the circular scale lies 5 divisions below the reference line. The diameter of a wire is then measured using this screw gauge. It is found that 4 linear scale divisions are clearly visible while 60 divisions on circular scale coincide with the reference line. The diameter of the wire is : (1) 3.35 mm (2) 4.65 mm (3) 4.55 mm (4) 4.60 mm

Q20.The value of net resistance of the network as shown in the given figure is : (1) 6Ω (2) (5/2)Ω (3) (15/4)Ω (4) (30/11)Ω

Q21.A particle is moving in one dimension (along 𝑥 axis) under the action of a variable force. It's initial position was 16 m right of origin. The variation of its position 𝑥 with time 𝑡 is given as 𝑥= – 3𝑡3 + 18𝑡2 + 16𝑡, where 𝑥 is in m and 𝑡 is in s . The velocity of the particle when its acceleration becomes zero is _________ m s-1 . JEE Main 2024 (01 Feb Shift 1) JEE Main Previous Year Paper

Q31.Compare the energies of following sets of quantum numbers for multielectron system. (A) n = 4, 1 = 1 (B) n = 4, l = 2 (C) n = 3, 1 = 1 (D) n = 3, 1 = 2 (E) n = 4, 1 = 0 Choose the correct answer from the options given below : (1) (B) > (A) > (C) > (E) > (D) (2) (E) < ( C ) < (D) < ( A ) < ( B ) (3) (E) > ( C ) > ( A ) > ( D ) > (B) (4) (C) < (E) < (D) < (A) < (B)

Q31.The electronic configuration for Neodymium is: [Atomic Number for Neodymium 60] JEE Main 2024 (27 Jan Shift 1) JEE Main Previous Year Paper (1) [Xe] 4f 4 6s2 (2) [Xe] 5f 47s2 (3) [Xe] 4f 6 6s2 (4) [Xe] 4f 15d16s2

Q31.A sample of CaCO3 and MgCO3 weighed 2 .21 g is ignited to constant weight of 1 .152 g. The composition of the mixture is: (Given molar mass in g mol−1, CaCO3: 100, MgCO3: 84) (1) 1 .187 𝑔 𝐶𝑎𝐶𝑂3 + 1 .023 𝑔 𝑀𝑔𝐶𝑂3 (2) 1 .023 𝑔 𝐶𝑎𝐶𝑂3 + 1 .023 𝑔 𝑀𝑔𝐶𝑂3 (3) 1 .187 𝑔 𝐶𝑎𝐶𝑂3 + 1 .187 𝑔 𝑀𝑔𝐶𝑂3 (4) 1 .023 𝑔 𝐶𝑎𝐶𝑂3 + 1 .187 𝑔 𝑀𝑔𝐶𝑂3

Q31.Match List I with List II Choose the correct answer from the options given below :- (1) A-II, B-III, C-I, D-IV (2) A-I, B-III, C-II, D-IV (3) A-II, B-IV, C-III, D-I (4) A-I, B-II, C-III, D-IV

Q31.The correct set of four quantum numbers for the valence electron of rubidium atom (Z = 37) is: (1) 5, 0, 0, + 12 (2) 5, 0, 1, + 12 (3) 5, 1, 0, + 12 (4) 5, 1, 1, + 12

Q31.The candela is the luminous intensity, in a given direction, of a source that emits monochromatic radiation of frequency ' A ' ×1012 hertz and that has a radiant intensity in that direction of ′ 1B′ watt per steradian. 'A' and 'B' are respectively (1) 540 and 683 (2) 450 and 683 (3) 450 and 1 (4) 540 and 1 683 683

Q31.The correct sequence of electron gain enthalpy of the elements listed below is A. Ar B. Br C. F D. S Choose the most appropriate from the options given below: (1) C > B > D > A (2) A > D > B > C (3) A > D > C > B (4) D > C > B > A

Q31.Which of the following cannot function as an oxidising agent? (1) N3 - (2) SO42 - (3) BrO3- (4) MnO4-

Q31.The number of radial node/s for 3p orbital is: (1) 1 (2) 4 (3) 2 (4) 3

Q31.Identify the correct statements about p-block elements and their compounds. (A) Non metals have higher electronegativity than metals. (B) Non metals have lower ionisation enthalpy than metals. (C) Compounds formed between highly reactive nonmetals and highly reactive metals are generally ionic. (D) The non-metal oxides are generally basic in nature. (E) The metal oxides are generally acidic or neutral in nature. Choose the correct answer from the options given below : (1) (B) and (D) only (2) (A) and (C) only (3) (D) and (E) only (4) (B) and (E) only

Q31.The density of ' x ' M solution (' X ' molar) of NaOH is 1.12 g mL−1 , while in molality, the concentration of the solution is 3 m(3molal). Then x is (Given : Molar mass of NaOH is 40 g/mol ) (1) 3.5 (2) 3.8 (3) 2.8 (4) 3.0

Q31.An organic compound has 42.1% carbon, 6.4% hydrogen and remainder is oxygen. If its molecular weight is 342, then its molecular formula is : (1) C11H18O12 (2) C12H20O12 (3) C12H22O11 (4) C14H20O10

Q31.Combustion of glucose (C6H12O6) produces CO2 and water. The amount of oxygen (in g) required for the complete combustion of 900 g of glucose is : [Molar mass of glucose in gmol−1 = 180 ] (1) 480 (2) 800 (3) 960 (4) 32

Q31.Molality ( m ) of 3M aqueous solution of NaCl is : (Given : Density of solution = 1.25 g mL−1 , Molar mass in gmol−1 : Na −23, Cl −35.5) JEE Main 2024 (06 Apr Shift 2) JEE Main Previous Year Paper (1) 1.9 m (2) 3.85 m (3) 2.79 m (4) 2.90 m