Practice Questions

Q29.A Zener of breakdown voltage VZ = 8 V and maximum Zener current, IZM = 10 mA is subjected to an input voltage Vi = 10 V with series resistance R = 100 Ω . In the given circuit RL represents the variable load resistance. The ratio of maximum and minimum value of RL is _____ .

Q29.The X −Y plane be taken as the boundary between two transparent media M1 and M2 . M1 in Z ≥0 has a refractive index of √2 and M2 with Z < 0 has a refractive index of √3. A ray of light travelling in M1 along → the direction given by the vector A = 4√3i −3√3j −5ˆk, is incident on the plane of separation. The value of difference between the angle of incident in M1 and the angle of refraction in M2 will be _____ degree.

Q29.In a hydrogen spectrum λ be the wavelength of first transition line of Lyman series. The wavelength difference will be " aλ" between the wavelength of 3rd transition line of Paschen series and that of 2nd transition line of Balmer Series where a = _____.

Q29.An object ' O' is placed at a distance of 100 cm in front of a concave mirror of radius of curvature 200 cm as shown in the figure. The object starts moving towards the mirror at a speed 2 cm s−1 . The position of the image from the mirror after 10 s will be at _____ cm.

Q30.A modulating signal 2sin6 . 28 × 106𝑡 is added to the carrier signal 4sin12 . 56 × 109𝑡 for amplitude modulation. The combined signal is passed through a non-linear square law device. The output is then passed through a band pass filter. The bandwidth of the output signal of band pass filter will be _____ MHz.

Q30.The current in a coil of self inductance 𝐿= 2 . 0 H is increasing according to the law 𝑖= 2sin𝑡2. Find the amount of energy spent (in J) during the period when the current changes from 0 to 2 A.

Q52. PCl5 dissociates as PCl5(g) ⇌PCl3(g) + Cl2(g) 5 moles of PCl5 are placed in a 200 litre vessel which contains 2 moles of N2 and is maintained at 600 K. The equilibrium pressure is 2. 46 atm . The equilibrium constant Kp for the dissociation of PCl5 is___ ×10−3 . (nearest integer) (Given: R = 0. 082 L atm K−1 mol−1 ; Assume ideal gas behaviour)

Q53.for a real gas at 25 °C temperature and high pressure ( 99 bar) the value of compressibility factor is 2 , so the value of Van 1der Waal's constant ' b' should be_____ ×10−2 L mol−1 (Given R = 0. 083 L bar K−1 mol−1 )

Q54.The major product ' A' of the following given reaction has sp2 hybridized carbon atoms. JEE Main 2022 (24 Jun Shift 1) JEE Main Previous Year Paper H+ 2, 7 -Dimethyl- 2, 6 -octadiene → A Major Product

Q54.Compound ' P' on nitration with dil. HNO3 yields two isomers (A) and (B). These isomers can be separated by steam distillations. Isomers (A) and (B) show the intramolecular and intermolecular hydrogen bonding respectively. Compound (P) on reaction with conc. HNO3 yields a yellow compound ' C', a strong acid. The number of oxygen atoms is present in compound ' C'

Q55.In the estimation of bromine, 0. 5 g of an organic compound gave 0. 40 g of silver bromide. The percentage of bromine in the given compound is % (nearest integer) (Relative atomic masses of Ag and Br are 108u and 80u , respectively).

Q56.The standard free energy change ΔG° for 50% dissociation of N2O4 into NO2 at 27 °C and 1 atm pressure is -x J mol-1. The value of x is - . . . . . J. (Nearest Integer) [Given : R = 8 . 31 J K-1 mol-1, log1 . 33 = 0 . 1239 ln10 = 2 . 3]

Q56.The cell potential for the given cell at 298 K Pt|H2(g, 1 bar)| H+(aq) Cu2+(aq) Cu(s) is 0. 31 V . The pH of the acidic solution is found to be 3, whereas the concentration of Cu2+ is 10x M. The value of x is _________. (Given: EΘ = 0. 34 V and 2.303F RT = 0. 06 V ) Cu2+ / Cu JEE Main 2022 (29 Jun Shift 2) JEE Main Previous Year Paper

Q57.Resistance of a conductivity cell (cell constant 129 m−1 ) filled with 74. 5 ppm solution of KCl is 100 Ω (labelled as solution 1). When the same cell is filled with KCl solution of 149 ppm, the resistance is 50 Ω (labelled as solution 2). The ratio of molar conductivity of solution 1 and solution 2 is i.e. ∧1 = x × 10−3 . The ∧2 value of x is____Given, molar mass of KCl is 74. 5 g mol−1 )

Q57.The distance between Na+ and Cl- ions in solid NaCl of density 43 . 1 gcm-3 is . . . . . × 10-10 m. (Nearest Integer) (Given : NA = 6 . 02 × 1023 mol-1)

Q58.The number of terminal oxygen atoms present in the product B obtained from the following reaction is FeCr2 O4 + Na2 CO3 + O2 →A + Fe2 O3 + CO2 A + H+ →B + H2O + Na+

Q58.Total number of isomers (including stereoisomers) obtain on monochlorination of methylcyclohexane is

Q58.The quantity of electricity in Faraday needed to reduce 1 mol of Cr2 O2−7 to Cr3+ is

Q58.Amongst FeCl3 . 3H2O, K3FeCN6 and CoNH36Cl3, the spin-only magnetic moment value of the inner-orbital complex that absorbs light at shortest wavelength is B.M. [nearest integer]

Q59.Consider the following metal complexes : CoNH3 3 + CoClNH35 2 + 3 - Co ( CN ) 6 CoNH35H2O3 + The spin-only magnetic moment value of the complex that absorbs light with shortest wavelength is B.M. (Nearest integer)

Q60.A sample of 4. 5 mg of an unknown monohydric alcohol, R −OH was added to methylmagnesium iodide. A gas is evolved and is collected and its volume measured to be 3. 1 mL. The molecular weight of the unknown alcohol is g/ mol. p is _______.

Q60.Reaction of [Co (H2O)6]2+ with excess ammonia and in the presence of oxygen results into a diamagnetic product. Number of electrons present in t2g -orbitals of the product is 1 (−1)n A

Q61.For z ∈C if the minimum value of ( z −3√2 + z −p√2i ) is 5√2 , then a value of (1) 3 (2) 72 (3) 4 (4) 92

Q81.Let S = {z ∈C : |z −2| ≤1, z(1 + i) + z(1 −i) ≤2} . Let |z −4 i| attains minimum and maximum values, + = α + β√5 , where α and β are integers, then the value respectively, at z1 ∈S and z2 ∈S . If 5(|z1|2 |z2|2) of α + β is equal to ______.

Q81.Let f(x) be a quadratic polynomial with leading coefficient 1 such that f(0) = p, p ≠0 , and f(1) = 31 . If the equations f(x) = 0 and fofofof(x) = 0 have a common real root, then f(−3) is equal to ______. JEE Main 2022 (25 Jul Shift 2) JEE Main Previous Year Paper + = k + 6√3 + 8√6 ,