JEE Main 2021 (Online) 24th February Morning Shift

Paper was held on
Wed, Feb 24, 2021 3:30 AM

## Chemistry

The electrode potential of M2+/M of 3d-series elements shows positive value for :

View Question Which of the following reagent is used for the following reaction ?
$$
\mathrm{CH}_3 \mathrm{CH}_2 \mathrm{CH}_3 \stackr

View Question Which of the following are isostructural pairs ?
A. $$SO_4^{2 - }$$ and $$CrO_4^{2 - }$$
B. SiCl4, and TiCl4
C. NH3 and

View Question Consider the elements Mg, Al, S, P and Si, the correct increasing order of their first ionization
enthalpy is :

View Question Out of the following, which type of interaction is reponsible for the stabilisation of $$\alpha $$-helix structure of pr

View Question Which of the following compound gives pink colour on reaction with phthalic anhydride in
conc. H2SO4 followed by treatme

View Question Given below are two statements :
Statement I : Colourless cupric metaborate is reduced to cuprous metaborate in a lumino

View Question In the following reaction the reason why meta-nitro product also formed is :

View Question What is the major product formed by HI on reaction with

View Question 'A' and 'B' in the following reactions are :

View Question Identify products A and B.

View Question What is the final product (major) 'A' in the given reaction ?

View Question The product formed in the first step of the reaction of
with excess $$\mathrm{Mg/Et_2O}$$ ($$\mathrm{Et=C_2H_5}$$) is

View Question Number of amphoteric compounds among the following is ________.
(A) BeO
(B) BaO
(C) Be(OH)2
(D) Sr(OH)2

View Question The stepwise formation of $${\left[ {Cu{{\left( {N{H_3}} \right)}_4}} \right]^{2 + }}$$ is given below:
The value of st

View Question A proton and a Li3+ nucleus are accelerated by the same potential. If $$\lambda _{Li}$$ and $$\lambda _p$$ denote the
de

View Question At 1990 K and 1 atm pressure, there are equal number of Cl2, molecules and Cl atoms in the
reaction mixture. The value o

View Question When 9.45 g of CICH2COOH is added to 500 mL of water, its freezing point drops by 0.5°C. The dissociation constant of CI

View Question 4.5 g of compound A (MW = 90) was used to make 250 mL of its aqueous solution. The
molarity of the solution in M is x $$

View Question The reaction of sulphur in alkaline medium is given below:
The values of 'a' is _______.
(Integer answer)

View Question For the reaction A(g) $$ \to $$ B(g) the value of the equilibrium constant at 300 K and 1 atm is equal to 100.0. The val

View Question Gaseous cyclobutene isomerises to butadiene in a first order process which has a 'k' value of 3.3 $$ \times $$ 10-4 s-1

View Question ## Mathematics

If $$\int {{{\cos x - \sin x} \over {\sqrt {8 - \sin 2x} }}} dx = a{\sin ^{ - 1}}\left( {{{\sin x + \cos x} \over b}} \r

View Question If f : R $$ \to $$ R is a function defined by f(x)= [x - 1] $$\cos \left( {{{2x - 1} \over 2}} \right)\pi $$, where [.]

View Question The population P = P(t) at time 't' of a certain species follows the differential equation
$${{dP} \over {dt}}$$
= 0.5P

View Question Let f : R → R be defined as f (x) = 2x – 1 and g : R - {1} → R be defined as g(x) =
$${{x - {1 \over 2}} \over {x - 1}}$

View Question The function
f(x) = $${{4{x^3} - 3{x^2}} \over 6} - 2\sin x + \left( {2x - 1} \right)\cos x$$ :

View Question $$\mathop {\lim }\limits_{x \to 0} {{\int\limits_0^{{x^2}} {\left( {\sin \sqrt t } \right)dt} } \over {{x^3}}}$$ is equa

View Question A scientific committee is to be formed from 6 Indians and 8 foreigners, which includes at
least 2 Indians and double the

View Question A man is walking on a straight line. The arithmetic mean
of the reciprocals of the intercepts of this line on the
coordi

View Question Let p and q be two positive numbers such that p + q = 2 and p4+q4 = 272. Then p and q are
roots of the equation :

View Question The area (in sq. units) of the part of the circle x2 + y2 = 36, which is outside the parabola
y2 = 9x, is :

View Question If
$${e^{\left( {{{\cos }^2}x + {{\cos }^4}x + {{\cos }^6}x + ...\infty } \right){{\log }_e}2}}$$
satisfies the equation

View Question The locus of the mid-point of the line segment joining the focus of the parabola y2 = 4ax to a
moving point of the parab

View Question The system of linear equations
3x - 2y - kz = 10
2x - 4y - 2z = 6
x+2y - z = 5m
is inconsistent if :

View Question Let P = $$\left[ {\matrix{
3 & { - 1} & { - 2} \cr
2 & 0 & \alpha \cr
3 & { - 5} &

View Question The minimum value of $$\alpha $$ for which the equation $${4 \over {\sin x}} + {1 \over {1 - \sin x}} = \alpha $$
has a

View Question If the least and the largest real values of a, for which the equation z + $$\alpha $$|z – 1| + 2i = 0
(z $$ \in $$ C and

View Question $$\mathop {\lim }\limits_{n \to \infty } \tan \left\{ {\sum\limits_{r = 1}^n {{{\tan }^{ - 1}}\left( {{1 \over {1 + r +

View Question Let A = {n $$ \in $$ N: n is a 3-digit number}
B = {9k + 2: k $$ \in $$

View Question If one of the diameters of the circle x2 + y2 - 2x - 6y + 6 = 0 is a chord of another circle 'C',
whose center is at (2,

View Question If $$\int\limits_{ - a}^a {\left( {\left| x \right| + \left| {x - 2} \right|} \right)} dx = 22$$, (a > 2) and [x] den

View Question Let M be any 3 $$ \times $$ 3 matrix with entries from the set {0, 1, 2}. The maximum number of such matrices, for which

View Question Let Bi (i = 1, 2, 3) be three independent events in a sample space. The probability that only B1 occur is $$\alpha $$, o

View Question ## Physics

A cube of side 'a' has point charges +Q located at each of its vertices except at the origin where the charge is $$-$$Q.

View Question In the given figure, a mass M is attached to a horizontal spring which is fixed on one side to a rigid support. The spri

View Question A current through a wire depends on time as i = $$\alpha$$0t + $$\beta$$t2where $$\alpha$$0 = 20 A/s and $$\beta$$ = 8 A

View Question Match List I with List II.
List I
List II
(a)
Isothermal
(i)
Pressure cons

View Question n mole of a perfect gas undergoes a cyclic process ABCA (see figure) consisting of the following processes.A $$ \to $$ B

View Question Each side of a box made of metal sheet in cubic shape is 'a' at room temperature 'T', the coefficient of linear expansio

View Question A cell E1 of emf 6V and internal resistance 2$$\Omega$$ is connected with another cell E2 of emf 4V and internal resista

View Question The focal length f is related to the radius of curvature r of the spherical convex mirror by :

View Question In a Young's double slit experiment, the width of the one of the slit is three times the other slit. The amplitude of th

View Question Four identical particles of equal masses 1 kg made to move along the circumference of a circle of radius 1 m under the a

View Question Consider two satellites S1 and S2 with periods of revolution 1 hr. and 8 hr. respectively revolving around a planet in c

View Question If Y, K and $$\eta $$ are the values of Young's modulus, bulk modulus and modulus of rigidity of any material respective

View Question If the velocity-time graph has the shape AMB, what would be the shape of the corresponding acceleration-time graph?

View Question In the given figure, the energy levels of hydrogen atom have been shown along with some transitions marked A, B, C, D an

View Question The work done by a gas molecule in an isolated system is given by, $$W = \alpha {\beta ^2}{e^{ - {{{x^2}} \over {\alpha

View Question Two stars of masses m and 2m at a distance d rotate about their common centre of mass in free space. The period of revol

View Question Two equal capacitors are first connected in series and then in parallel. The ratio of the equivalent capacities in the t

View Question Moment of inertia (M. I.) of four bodies, having same mass and radius, are reported as; I1 = M.I. of thin circular ring

View Question An unpolarised light beam is incident on the polarizer of a polarization experiment and the intensity of light beam emer

View Question A ball with a speed of 9 m/s collides with another identical ball at rest. After the collision, the direction of each ba

View Question An electromagnetic wave of frequency 5 GHz, is travelling in a medium whose relative electric permittivity and relative

View Question A hydraulic press can lift 100 kg when a mass 'm' is placed on the smaller piston. It can lift ___________ kg when the d

View Question An inclined plane is bent in such a way that the vertical cross-section is given by $$y = {{{x^2}} \over 4}$$ where y is

View Question A common transistor radio set requires 12 V (D.C.) for its operation. The D.C. source is constructed by using a transfor

View Question The coefficient of static friction between a wooden block of mass 0.5 kg and a vertical rough wall is 0.2. The magnitude

View Question In connection with the circuit drawn below, the value of current flowing through 2 k$$\Omega$$ resistor is _________ $$\

View Question Given below are two statements : Statement I : Two photons having equal linear momenta have equal wavelengths.Statement

View Question