JEE Main 2021 (Online) 24th February Evening Shift

Paper was held on
Wed, Feb 24, 2021 9:30 AM

## Chemistry

The correct order of the following compounds showing increasing tendency towards nucleophilic substitution reaction is :

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The incorrect statement among the following is :

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In polymer Buna-S : 'S' stands for :

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Given below are two statements : one is labelled as Assertion A and the other is labelled as Reason R.Assertion A : Hydr

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Given below are two statements :Statement I : The value of the parameter "Biochemical Oxygen Demand (BOD)" is important

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Which one of the following compounds is non-aromatic?

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According to Bohr's atomic theory :(A) Kinetic energy of electron is $$ \propto {{{Z^2}} \over {{n^2}}}$$.(B) The produc

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Most suitable salt which can be used for efficient clotting of blood will be :

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Which one of the following carbonyl compounds cannot be prepared by addition of water on an alkyne in the presence of Hg

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The correct set from the following in which both pairs are in correct order of melting point is :

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What is the correct sequence of reagents used for converting nitrobenzene into m-dibromobenzene?

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The calculated magnetic moments (spin only value) for species $${[FeC{l_4}]^{2 - }}$$, $${[Co{({C_2}{O_4})_3}]^{3 - }}$$

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Which of the following reagent is suitable for the preparation of the product in the above reaction?

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Math List - I with List - II.
List I (Metal)
List II (Ores)
(a)
Aluminium
(i)

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What is the correct order of the following elements with respect to their density?

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Match List - I and List - II.
List I
List II
(a)
Valium
(i)
Antifertility

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The correct shape and $$I - I - I$$ bond angles respectively in $$I_3^ - $$ ion are :

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The diazonium salt of which of the following compounds will form a coloured dye on reaction with $$\beta$$-Naphthol in N

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Match List - I and List - II.
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Match List - I with List - II.
List I (Salt)
List II (Flame colour wavelength)
(a)

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The formula of a gaseous hydrocarbon which requires 6 times of its own volume of O2 for complete oxidation and produces

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Among the following allotropic forms of sulphur, the number of allotropic forms, which will show paramagnetism is ______

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The solubility product of PbI2 is 8.0 $$\times$$ 10$$-$$9. The solubility of lead iodide in 0.1 molar solution of lead n

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1.86 g of aniline completely reacts to form acetanilide. 10% of the product is lost during purification. Amount of aceta

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The volume occupied by 4.75 g of acetylene gas at 50$$^\circ$$C and 740 mmHg pressure is __________ L. (Rounded off to t

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Assuming ideal behaviour, the magnitude of log K for the following reaction at 25$$^\circ$$C is x $$\times$$ 10$$-$$1. T

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C6H6 freezes at 5.5$$^\circ$$C. The temperature at which a solution of 10g of C4H10 in 200g of C6H6 freeze is __________

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Sucrose hydrolyses in acid solution into glucose and fructose following first order rate law with a half-life of 3.33 h

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The magnitude of the change in oxidising power of the $$MnO_4^ - /M{n^{2 + }}$$ couple is x $$\times$$ 10$$-$$4 V, if th

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The total number of amines among the following which can be synthesized by Gabriel synthesis is __________.

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## Mathematics

If a curve y = f(x) passes through the point (1, 2) and satisfies $$x {{dy} \over {dx}} + y = b{x^4}$$, then for what va

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For which of the following curves, the line $$x + \sqrt 3 y = 2\sqrt 3 $$ is the tangent at the point $$\left( {{{3\sqrt

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Let A and B be 3 $$\times$$ 3 real matrices such that A is symmetric matrix and B is skew-symmetric matrix. Then the sys

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The value of the integral, $$\int\limits_1^3 {[{x^2} - 2x - 2]dx} $$, where [x] denotes the greatest integer less than o

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Let a, b, c be in arithmetic progression. Let the centroid of the triangle with vertices (a, c), (2, b) and (a, b) be $$

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Let a, b$$ \in $$R. If the mirror image of the point P(a, 6, 9) with respect to the line $${{x - 3} \over 7} = {{y - 2}

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For the system of linear equations:$$x - 2y = 1,x - y + kz = - 2,ky + 4z = 6,k \in R$$,consider the following statement

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Let f(x) be a differentiable function defined on [0, 2] such that f'(x) = f'(2 $$-$$ x) for all x$$ \in $$ (0, 2), f(0)

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The negation of the statement $$ \sim p \wedge (p \vee q)$$ is :

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For the statements p and q, consider the following compound statements :(a) $$( \sim q \wedge (p \to q)) \to \sim p$$(b

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If $$n \ge 2$$ is a positive integer, then the sum of the series $${}^{n + 1}{C_2} + 2\left( {{}^2{C_2} + {}^3{C_2} + {}

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Let f be a twice differentiable function defined on R such that f(0) = 1, f'(0) = 2 and f'(x) $$ \ne $$ 0 for all x $$ \

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Let $$f:R \to R$$ be defined as$$f(x) = \left\{ {\matrix{
{ - 55x,} & {if\,x < - 5} \cr
{2{x^3} - 3{x^2}

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If P is a point on the parabola y = x2 + 4 which is closest to the straight line y = 4x $$-$$ 1, then the co-ordinates o

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The vector equation of the plane passing through the intersection of the planes $$\overrightarrow r .\left( {\widehat i

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The angle of elevation of a jet plane from a point A on the ground is 60$$^\circ$$. After a flight of 20 seconds at the

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The probability that two randomly selected subsets of the set {1, 2, 3, 4, 5} have exactly two elements in their interse

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A possible value of $$\tan \left( {{1 \over 4}{{\sin }^{ - 1}}{{\sqrt {63} } \over 8}} \right)$$ is :

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If the curve y = ax2 + bx + c, x$$ \in $$R, passes through the point (1, 2) and the tangent line to this curve at origin

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The area of the region : $$R = \{ (x,y):5{x^2} \le y \le 2{x^2} + 9\} $$ is :

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Let a point P be such that its distance from the point (5, 0) is thrice the distance of P from the point ($$-$$5, 0). If

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If the variance of 10 natural numbers 1, 1, 1, ....., 1, k is less than 10, then the maximum possible value of k is ____

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Let $$\lambda$$ be an integer. If the shortest distance between the lines x $$-$$ $$\lambda$$ = 2y $$-$$ 1 = $$-$$2z and

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If a + $$\alpha$$ = 1, b + $$\beta$$ = 2 and $$af(x) + \alpha f\left( {{1 \over x}} \right) = bx + {\beta \over x},x \n

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If the area of the triangle formed by the positive x-axis, the normal and the tangent to the circle (x $$-$$ 2)2 + (y $$

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Let $$i = \sqrt { - 1} $$. If $${{{{\left( { - 1 + i\sqrt 3 } \right)}^{21}}} \over {{{(1 - i)}^{24}}}} + {{{{\left( {1

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For integers n and r, let $$\left( {\matrix{
n \cr
r \cr
} } \right) = \left\{ {\matrix{
{{}^n{C_r},} &am

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The number of the real roots of the equation $${(x + 1)^2} + |x - 5| = {{27} \over 4}$$ is ________.

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The students S1, S2, ....., S10 are to be divided into 3 groups A, B and C such that each group has at least one student

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The sum of first four terms of a geometric progression (G. P.) is $${{65} \over {12}}$$ and the sum of their respective

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## Physics

In the given figure, a body of mass M is held between two massless springs, on a smooth inclined plane. The free ends of

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If the source of light used in a Young's double slit experiment is changed from red to violet :

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The logic circuit shown above is equivalent to :

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Figure shows a circuit that contains four identical resistors with resistance R = 2.0$$\Omega$$, two identical inductors

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A particle is projected with velocity v0 along x-axis. A damping force is acting on the particle which is proportional t

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An X-ray tube is operated at 1.24 million volt. The shortest wavelength of the produced photon will be :

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If one mole of an ideal gas at (P1, V1) is allowed to expand reversibly and isothermally (A to B) its pressure is reduce

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A body weights 49N on a spring balance at the north pole. What will be its weight recorded on the same weighing machine,

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When a particle executes SHM, the nature of graphical representation of velocity as a function of displacement is :

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The period of oscillation of a simple pendulum is $$T = 2\pi \sqrt {{L \over g}} $$. Measured value of 'L' is 1.0 m from

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A soft ferromagnetic material is placed in an external magnetic field. The magnetic domains :

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Which of the following equations represents a travelling wave?

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Given below are two statements :Statement I : PN junction diodes can be used to function as transistor, simply by connec

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Two electrons each are fixed at a distance '2d'. A third charge proton placed at the midpoint is displaced slightly by a

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On the basis of kinetic theory of gases, the gas exerts pressure because its molecules :

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Match List - I with List - II.
List I
List II
(a)
Source of microwave frequency

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A circular hole of radius $$\left( {{a \over 2}} \right)$$ is cut out of a circular disc of radius 'a' as shown in figur

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Zener breakdown occurs in a p $$-$$ n junction having p and n both :

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The de-Broglie wavelength of a proton and $$\alpha$$-particle are equal. The ratio of their velocities is :

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According to Bohr atomic model, in which of the following transitions will the frequency be maximum?

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A uniform metallic wire is elongated by 0.04 m when subjected to a linear force F. The elongation, if its length and dia

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An electromagnetic wave of frequency 3 GHz enters a dielectric medium of relative electric permittivity 2.25 from vacuum

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A cylindrical wire of radius 0.5 mm and conductivity 5 $$\times$$ 107 S/m is subjected to an electric field of 10 mV/m.

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Two solids A and B of mass 1 kg and 2 kg respectively are moving with equal linear momentum. The ratio of their kinetic

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The root mean square speed of molecules of a given mass of a gas at 27$$^\circ$$C and 1 atmosphere pressure is 200 ms$$-

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A series L-C-R circuit is designed to resonate at an angular frequency $$\omega$$0 = 105 rad/s. The circuit draws 16W po

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A signal of 0.1 kW is transmitted in a cable. The attenuation of cable is $$-$$5 dB per km and cable length is 20 km. Th

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A point charge of +12$$\mu$$C is at a distance 6 cm vertically above the centre of a square of side 12 cm as shown in fi

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Two cars are approaching each other at an equal speed of 7.2 km/hr. When they see each other, both blow horns having fre

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A uniform thin bar of mass 6 kg and length 2.4 meter is bent to make an equilateral hexagon. The moment of inertia about

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