Practice Questions

Q45.A body of mass ' m ' connected to a massless and unstretchable string goes in verticle circle of radius ' R 'under gravity g. The other end of the string is fixed at the center of circle. If velocity at top of circular path is n√gR, where, n ⩾1, then ratio of kinetic energy of the body at bottom to that at top of the circle is (1) n2 (2) n2+4 n2+4 n2 (3) n+4 (4) n n n+4

Q45.Which of the following resistivity ( ρ ) v/s temperature (T) curves is most suitable to be used in wire bound standard resistors? (1) (2) (3) (4)

Q45.An electric dipole is placed at a distance of 2 cm from an infinite plane sheet having positive charge density σo . Choose the correct option from the following. (1) Potential energy and torque both are maximum. (2) Torque on dipole is zero and net force is directed away from the sheet. (3) Torque on dipole is zero and net force acts (4) Potential energy of dipole is minimum and torque towards the sheet. is zero.

Q45.A proton of mass ' mp ' has same energy as that of a photon of wavelength ' λ '. If the proton is moving at non- relativistic speed, then ratio of its de Broglie wavelength to the wavelength of photon is. (1) 1 (2) 1 c √Emp c √2Emp (3) 1 (4) 1 E 2c √Emp c √ 2 mp

Q45. In the circuit shown here, assuming threshold voltage of diode is negligibly small, then voltage VAB is correctly represented by : (1) VAB would be zero at all times (2) (3) (4)

Q51.Consider the equilibrium CO( g) + 3H2( g) ⇌CH4( g) + H2O( g) If the pressure applied over the system increases by two fold at constant temperature then (A) Concentration of reactants and products increases. (B) Equilibrium will shift in forward direction. (C) Equilibrium constant increases since concentration of products increases. (D) Equilibrium constant remains unchanged as concentration of reactants and products remain same. Choose the correct answer from the options given below : (1) (A), (B) and (C) only (2) (A) and (B) only (3) (A), (B) and (D) only (4) (B) and (C) only

Q51. List - I List - II (Complex) (Hybridisation & Magnetic characters) (A) [MnBr4]2− (I) d2s3 & diamagnetic Match List - I with List - II. (B) [FeF6]3− (II) sp3 d2 & paramagnetic (C) [Co(C2O4)3]3− (III) sp3 & diamagnetic (D) [Ni(CO)4] (IV) sp3 & paramagnetic Choose the correct answer from the options given below : (1) (A) −(IV), (B) −(II), (C) −(I), (D) −(III) (2) (A) −(III), (B) −(I), (C) −(II), (D) −(IV) (3) (A) −(IV), (B) −(I), (C) −(II), (D) −(III) (4) (A) −(III), (B) −(II), (C) −(I), (D) −(IV)

Q51.The carbohydrate "Ribose" present in DNA, is A. A pentose sugar B. present in pyranose from C. in "D" configuration D. a reducing sugar, when free E. in ∝-anomeric form Choose the correct answer from the 2025 (24 Jan Shift 1) JEE Main Previous Year Paper options given below: (1) A, D and E Only (2) A, C and D Only (3) A, B and E Only (4) B, D and E Only

Q51.Identify the products [A] and [B], respectively in the following reaction : 2025 (23 Jan Shift 2) JEE Main Previous Year Paper (1) (2) (3) (4) −−

Q52.J of energy is transferred as heat to 0.5 mol of Argon gas at 298 K and 1.00 atm. The final temperature and the change in internal energy respectively are: Given : R = 8.3 J K−1 mol−1 (1) 378 K and 500 J (2) 368 K and 500 J (3) 348 K and 300 J (4) 378 K and 300 J

Q52.The incorrect statements regarding geometrical isomerism are : (A) Propene shows geometrical isomerism. (B) Trans isomer has identical atoms/groups on the opposite sides of the double bond. (C) Cis-but-2-ene has higher dipole moment than trans-but-2-ene. (D) 2-methylbut-2-ene shows two geometrical isomers. (E) Trans-isomer has lower melting point than cis isomer. Choose the correct answer from the options given below : (1) (A) and (E) Only (2) (A), (D) and (E) Only (3) (B) and (C) Only (4) (C), (D) and (E) Only

Q52.Density of 3 M NaCl solution is 1.25 g/mL. The molality of the solution is : (1) 1.79 m (2) 2.79 m (3) 2 m (4) 3 m

Q52.Consider the following reactions K2Cr2O7 KOH→ [A] H2SO4→ [ B] + K2SO4 The products [A] and [B], −H2O −H2O respectively are : (1) K2CrO4 and CrO (2) K2CrO4 and Cr2O3 (3) K2CrO4 and K2Cr2O7 (4) K2Cr(OH)6 and Cr2O3

Q52.Both acetaldehyde and acetone (individually) undergo which of the following reactions? A. Iodoform Reaction B. Cannizaro Reaction C. Aldol Condensation D. Tollen's Test E. Clemmensen Reduction Choose the correct answer from the options given below: (1) A, B and D Only (2) C and E Only (3) A, C and E Only (4) B, C and D Only

Q52.Match List - I with List - II. Choose the correct answer from the options given below : (1) (A) −(III), (B) −(I), (C) −(IV), (D) −(II) (2) (A) −(III), (B) −(I), (C) −(II), (D) −(IV) (3) (A) −(IV), (B) −(II), (C) −(III), (D) −(I) (4) (A) −(II), (B) −(IV), (C) −(I), (D) −(III)

Q52.Drug X becomes ineffective after 50% decomposition. The original concentration of drug in a bottle was 16mg/mL which becomes 4mg/mL in 12 months. The expiry time of the drug in months is __________ Assume that the decomposition of the drug follows first order kinetics. (1) 2 (2) 6 (3) 12 (4) 3

Q52.The complex that shows Facial - Meridional isomerism is: (1) 1.[Co(en)2Cl2]+ (2) [Co(en)3]3+ (3) [Co(NH3)3Cl3] (4) [Co(NH3)4Cl2]+ Q53. +2.0v 0.8v −0.5v−−−FeO2−4 → Fe3+ → Fe2+ → Fe0 In the above diagram, the standard electrode potentials are given in volts (over the arrow). The value of EO is FeO2−4 /Fe2+ (1) 2.1 V (2) 1 .7 V (3) 1 .4 V (4) 1 .2 V

Q53.The effect of temperature on spontaneity of reactions are represented as : (1) (B) and (C) only (2) (B) and (D) only (3) (A) and (D) only (4) (A) and (C) only

Q53.Identify product [A], [B] and [C] in the following reaction sequence. (1) (2) (3) (4)

Q53.At temperature T, compound AB2( g) dissociates as AB2( g) ⇌AB(g) + 12 B2( g) having degree of dissociation x (small compared to unity). The correct expression for x in terms of Kp and p is 2025 (29 Jan Shift 1) JEE Main Previous Year Paper (1) 4√2Kpp (2) 3√2Kpp (3) 3√2 pK2p (4) √Kp

Q53.The product (A) formed in the following reaction sequence is (1) (2) (3) (4)

Q53. O2 gas will be evolved as a product of electrolysis of : (A) an aqueous solution of AgNO3 using silver electrodes. (B) an aqueous solution of AgNO3 using platinum electrodes. (C) a dilute solution of H2SO4 using platinum electrodes. (D) a high concentration solution of H2SO4 using platinum electrodes. Choose the correct answer from the options given below : (1) (A) and (C) only (2) (B) and (C) only (3) (A) and (D) only (4) (B) and (D) only

Q53.Which of the following oxidation reactions are carried out by both K2Cr2O7 and KMnO4 in acidic medium? A. Γ−→I2 B. S 2−→S C. Fe2+ →Fe3+ D. Γ−→IO3− E. S2O32−→SO42− Choose the correct answer from the options given below: (1) C, D and E Only (2) B, C and D Only (3) A, D and E Only (4) A, B and C Only

Q53.A liquid when kept inside a thermally insulated closed vessel at 25∘C was mechanically stirred from outside. What will be the correct option for the following thermodynamic parameters ? (1) ΔU < 0, q = 0, w > 0 (2) ΔU = 0, q = 0, w = 0 (3) ΔU > 0, q = 0, w > 0 (4) ΔU = 0, q < 0, w > 0

Q54.An element ' E ′ has the ionisation enthalpy value of 374 kJ mol−1 . ' E ' reacts with elements A, B, C and D with electron gain enthalpy values of −328, −349, −325 and −295 kJ mol−1 , respectively. The correct order of the products EA, EB, EC and ED in terms of ionic character is : (1) ED > EC > EB > EA (2) EA > EB > EC > ED (3) EB > EA > EC > ED (4) ED > EC > EA > EB