JEE Main 2020 (Online) 8th January Morning Slot
Paper was held on
Wed, Jan 8, 2020 3:30 AM
Chemistry
1
The third ionization enthalpy is minimum for :
2
A graph of vapour pressure and temperature for three different liquids X, Y, and Z is shown below :
The following inferences are made :
(A) X has higher intermolecular interactions compared to Y.
(B) X has lower intermolecular interactions compared to Y.
(C) Z has lower intermolecular interactions compared to Y.
The correct inference (s) is / are :
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(A) X has higher intermolecular interactions compared to Y.
(B) X has lower intermolecular interactions compared to Y.
(C) Z has lower intermolecular interactions compared to Y.
The correct inference (s) is / are :
3
Arrange the following compounds in increasing order of C–OH bond length :
methanol, phenol, p-ethoxyphenol
methanol, phenol, p-ethoxyphenol
4
The complex that can show fac- and mer-isomers is :
5
The major products A and B in the following reactions are :
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6
For the Balmer series in the spectrum of H atom,
$$\overline \nu = {R_H}\left\{ {{1 \over {n_1^2}} - {1 \over {n_2^2}}} \right\}$$, the correct statements among (I) to (IV) are :
(I) As wavelength decreases, the lines in the series converge
(II) The integer n1 is equal to 2
(III) The lines of longest wavelength corresponds to n2 = 3
(IV) The ionization energy of hydrogen can be calculated from wave number of these lines
$$\overline \nu = {R_H}\left\{ {{1 \over {n_1^2}} - {1 \over {n_2^2}}} \right\}$$, the correct statements among (I) to (IV) are :
(I) As wavelength decreases, the lines in the series converge
(II) The integer n1 is equal to 2
(III) The lines of longest wavelength corresponds to n2 = 3
(IV) The ionization energy of hydrogen can be calculated from wave number of these lines
7
The magnitude of work done by a gas that undergoes a reversible expansion along the path ABC shown in
the figure is _______.
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8
Ferrous sulphate heptahydrate is used to fortify foods with iron. The amount (in grams) of the salt required to
achieve 10 ppm of iron in 100 kg of wheat is _______.
Atomic weight : Fe = 55.85; S = 32.00; O = 16.00
Atomic weight : Fe = 55.85; S = 32.00; O = 16.00
9
What would be the electrode potential for the given half cell reaction at pH = 5?
______.
2H2O $$ \to $$ O2 + 4H$$ \oplus $$ + 4e– ; $$E_{red}^0$$ = 1.23 V
(R = 8.314 J mol–1 K–1 ; Temp = 298 k;
oxygen under std. atm. pressure of 1 bar)
2H2O $$ \to $$ O2 + 4H$$ \oplus $$ + 4e– ; $$E_{red}^0$$ = 1.23 V
(R = 8.314 J mol–1 K–1 ; Temp = 298 k;
oxygen under std. atm. pressure of 1 bar)
10
The volume (in mL) of 0.125 M AgNO3 required to quantitatively precipitate chloride ions in 0.3 g of
[Co(NH3)6]Cl3 is ________.
M[Co(NH3)6Cl3] = 267.46 g/mol
MAgNO3 = 169.87 g/mol
M[Co(NH3)6Cl3] = 267.46 g/mol
MAgNO3 = 169.87 g/mol
11
The decreasing order of reactivity towards dehydrohalogenation (E1) reaction of the following compounds is :
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12
The first ionization energy (in kJ/mol) of Na, Mg, Al and Si respectively, are :
13
Which of the following statement is not true for glucose?
14
The rate of a certain biochemical reaction at physiological temperature (T) occurs 106 times faster with
enzyme than without. The change in the activation energy upon adding enzyme is :
15
The strength of an aqueous NaOH solution is most accurately determined by titrating :
(Note : consider that an appropriate indicator is used)
(Note : consider that an appropriate indicator is used)
16
The major product of the following reaction is :
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17
The stoichiometry and solubility product of a salt with the solubility curve given below is, respectively :
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18
A flask contains a mixture of isohexane and 3-methylpentane. One of the liquids boils at 63oC while the
other boils at 60oC What is the best way to separate the two liquids and which one will be distilled out first ?
19
The predominant intermolecular forces present in ethyl acetate, a liquid, are:
20
The most suitable reagent for the given conversion is :
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Mathematics
1
An urn contains 5 red marbles, 4 black marbles
and 3 white marbles. Then the number of ways
in which 4 marbles can be drawn so that at the
most three of them are red is ___________.
2
The least positive value of 'a' for which the
equation
2x2 + (a – 10)x + $${{33} \over 2}$$ = 2a has real roots is
2x2 + (a – 10)x + $${{33} \over 2}$$ = 2a has real roots is
3
The number of all 3 × 3 matrices A, with
enteries from the set {–1, 0, 1} such that the sum
of the diagonal elements of AAT is 3, is
4
The shortest distance between the lines
$${{x - 3} \over 3} = {{y - 8} \over { - 1}} = {{z - 3} \over 1}$$ and
$${{x + 3} \over { - 3}} = {{y + 7} \over 2} = {{z - 6} \over 4}$$ is :
$${{x - 3} \over 3} = {{y - 8} \over { - 1}} = {{z - 3} \over 1}$$ and
$${{x + 3} \over { - 3}} = {{y + 7} \over 2} = {{z - 6} \over 4}$$ is :
5
Let ƒ(x) = xcos–1(–sin|x|), $$x \in \left[ { - {\pi \over 2},{\pi \over 2}} \right]$$, then
which of the following is true?
6
The inverse function of
f(x) = $${{{8^{2x}} - {8^{ - 2x}}} \over {{8^{2x}} + {8^{ - 2x}}}}$$, x $$ \in $$ (-1, 1), is :
f(x) = $${{{8^{2x}} - {8^{ - 2x}}} \over {{8^{2x}} + {8^{ - 2x}}}}$$, x $$ \in $$ (-1, 1), is :
7
If $$\int {{{\cos xdx} \over {{{\sin }^3}x{{\left( {1 + {{\sin }^6}x} \right)}^{2/3}}}}} = f\left( x \right){\left( {1 + {{\sin }^6}x} \right)^{1/\lambda }} + c$$
where c is a constant of integration, then $$\lambda f\left( {{\pi \over 3}} \right)$$ is equal to
where c is a constant of integration, then $$\lambda f\left( {{\pi \over 3}} \right)$$ is equal to
8
Let A and B be two independent events such
that
P(A) = $${1 \over 3}$$ and P(B) = $${1 \over 6}$$.
Then, which of the following is TRUE?
P(A) = $${1 \over 3}$$ and P(B) = $${1 \over 6}$$.
Then, which of the following is TRUE?
9
The locus of a point which divides the line
segment joining the point (0, –1) and a point on
the parabola, x2 = 4y, internally in the ratio
1 : 2, is :
10
For which of the following ordered pairs ($$\mu $$, $$\delta $$),
the system of linear equations
x + 2y + 3z = 1
3x + 4y + 5z = $$\mu $$
4x + 4y + 4z = $$\delta $$
is inconsistent ?
x + 2y + 3z = 1
3x + 4y + 5z = $$\mu $$
4x + 4y + 4z = $$\delta $$
is inconsistent ?
11
Let y = y(x) be a solution of the differential
equation,
$$\sqrt {1 - {x^2}} {{dy} \over {dx}} + \sqrt {1 - {y^2}} = 0$$, |x| < 1.
If $$y\left( {{1 \over 2}} \right) = {{\sqrt 3 } \over 2}$$, then $$y\left( { - {1 \over {\sqrt 2 }}} \right)$$ is equal to :
$$\sqrt {1 - {x^2}} {{dy} \over {dx}} + \sqrt {1 - {y^2}} = 0$$, |x| < 1.
If $$y\left( {{1 \over 2}} \right) = {{\sqrt 3 } \over 2}$$, then $$y\left( { - {1 \over {\sqrt 2 }}} \right)$$ is equal to :
12
For a > 0, let the curves C1 : y2 = ax and
C2 : x2 = ay intersect at origin O and a point P.
Let the line x = b (0 < b < a) intersect the chord
OP and the x-axis at points Q and R,
respectively. If the line x = b bisects the area
bounded by the curves, C1 and C2, and the area of
$$\Delta $$OQR = $${1 \over 2}$$, then 'a' satisfies the equation :
$$\Delta $$OQR = $${1 \over 2}$$, then 'a' satisfies the equation :
13
The mean and the standard deviation (s.d.) of
10 observations are 20 and 2 resepectively.
Each of these 10 observations is multiplied by
p and then reduced by q, where p $$ \ne $$ 0 and
q $$ \ne $$ 0. If the new mean and new s.d. become
half of their original values, then q is equal to
14
Let two points be A(1, –1) and B(0, 2). If a point
P(x', y') be such that the area of $$\Delta $$PAB = 5 sq.
units and it lies on the line, 3x + y – 4$$\lambda $$ = 0,
then a value of $$\lambda $$ is :
15
If the equation, x2 + bx + 45 = 0 (b $$ \in $$ R) has
conjugate complex roots and they satisfy
|z +1| = 2$$\sqrt {10} $$ , then :
16
Let ƒ(x) = (sin(tan–1x) + sin(cot–1x))2 – 1, |x| > 1.
If $${{dy} \over {dx}} = {1 \over 2}{d \over {dx}}\left( {{{\sin }^{ - 1}}\left( {f\left( x \right)} \right)} \right)$$ and $$y\left( {\sqrt 3 } \right) = {\pi \over 6}$$, then y($${ - \sqrt 3 }$$) is equal to :
If $${{dy} \over {dx}} = {1 \over 2}{d \over {dx}}\left( {{{\sin }^{ - 1}}\left( {f\left( x \right)} \right)} \right)$$ and $$y\left( {\sqrt 3 } \right) = {\pi \over 6}$$, then y($${ - \sqrt 3 }$$) is equal to :
17
$$\mathop {\lim }\limits_{x \to 0} {\left( {{{3{x^2} + 2} \over {7{x^2} + 2}}} \right)^{{1 \over {{x^2}}}}}$$ is equal to
18
Let ƒ : R $$ \to $$ R be such that for all
x $$ \in $$ R
(21+x + 21–x), ƒ(x) and (3x + 3–x) are in A.P.,
then the minimum value of ƒ(x) is
(21+x + 21–x), ƒ(x) and (3x + 3–x) are in A.P.,
then the minimum value of ƒ(x) is
19
If a, b and c are the greatest value of 19Cp, 20Cq
and 21Cr respectively, then :
Physics
1
In finding the electric field using Gauss Law
the formula $$\left| {\overrightarrow E } \right| = {{{q_{enc}}} \over {{\varepsilon _0}\left| A \right|}}$$ is applicable. In the
formula $${{\varepsilon _0}}$$ is permittivity of free space, A is the
area of Gaussian surface and qenc is charge
enclosed by the Gaussian surface. The equation
can be used in which of the following situation?
2
When photon of energy 4.0 eV strikes the
surface of a metal A, the ejected photoelectrons
have maximum kinetic energy TA eV end
de-Broglie wavelength $$\lambda _A$$. The maximum
kinetic energy of photoelectrons liberated from
another metal B by photon of energy 4.50 eV
is TB = (TA – 1.5) eV. If the de-Broglie
wavelength of these photoelectrons $$\lambda _B$$ = 2$$\lambda _A$$,
then the work function of metal B is :
3
The coordinates of centre of mass of a uniform
flag shaped lamina (thin flat plate) of mass 4kg.
(The coordinates of the same are shown in
figure) are :
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4
Consider a uniform rod of mass M = 4m and
length $$\ell $$ pivoted about its centre. A mass m
moving with velocity v making angle $$\theta = {\pi \over 4}$$ to
the rod's long axis collides with one end of the
rod and sticks to it. The angular speed of the
rod-mass system just after the collision is :
5
The dimension of stopping potential V0 in photoelectric effect in units of Planck's constant 'h', speed of light 'c' and Gravitational constant 'G' and ampere A is :
6
Consider a solid sphere of radius R and mass
density
$$\rho \left( r \right) = {\rho _0}\left( {1 - {{{r^2}} \over {{R^2}}}} \right)$$ , $$0 < r \le R$$
The minimum density of a liquid in which it will float is :
$$\rho \left( r \right) = {\rho _0}\left( {1 - {{{r^2}} \over {{R^2}}}} \right)$$ , $$0 < r \le R$$
The minimum density of a liquid in which it will float is :
7
Consider two solid spheres of radii R1 = 1m,
R2 = 2m and masses M1 and M2, respectively.
The gravitational field due to sphere (1) and (2) are shown. The value of $${{{M_1}} \over {{M_2}}}$$ is :
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8
Three charged particle A, B and C with charges
–4q, 2q and –2q are present on the
circumference of a circle of radius d. the charged
particles A, C and centre O of the circle formed
an equilateral triangle as shown in figure. Electric
field at O along x-direction is :
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9
A particle is moving along the x-axis with its
coordinate with the time 't' given be
x(t) = 10 + 8t – 3t2. Another particle is moving the y-axis with its coordinate as a function of time given by y(t) = 5 – 8t3.
At t = 1s, the speed of the second particle as measured in the frame of the first particle is given as $$\sqrt v $$. Then v (in m/s) is ______.
x(t) = 10 + 8t – 3t2. Another particle is moving the y-axis with its coordinate as a function of time given by y(t) = 5 – 8t3.
At t = 1s, the speed of the second particle as measured in the frame of the first particle is given as $$\sqrt v $$. Then v (in m/s) is ______.
10
A one metre long (both ends open) organ pipe
is kept in a gas that has double the density of
air at STP. Assuming the speed of sound in air
at STP is 300 m/s, the frequency difference
between the fundamental and second harmonic
of this pipe is ________ Hz.
11
A point object in air is in front of the curved
surface of a plano-convex lens. The radius of
curvature of the curved surface is 30 cm and
the refractive index of the lens material is 1.5,
then the focal length of the lens (in cm)
is ______.
12
A body A, of mass m = 0.1 kg has an initial
velocity of 3$$\widehat i$$ ms-1 . It collides elastically with
another body, B of the same mass which has
an initial velocity of 5$$\widehat j$$ ms-1. After collision,
A moves with a velocity $$\overrightarrow v = 4\left( {\widehat i + \widehat j} \right)$$. The
energy of B after collision is written as $${x \over {10}}$$. The value of x is ___________.
13
The critical angle of a medium for a specific wavelength, if the medium has relative permittivity 3 and relative permeability $${4 \over 3}$$ for this wavelength, will be :
14
Effective capacitance of parallel combination
of two capacitors C1 and C2 is 10 μF. When
these capacitors are individually connected to
a voltage source of 1V, the energy stored in the
capacitor C2 is 4 times that of C1. If these
capacitors are connected in series, their
effective capacitance will be :
15
A leak proof cylinder of length 1m, made of
a metal which has very low coefficient of
expansion is floating vertically in water at 0°C
such that its height above the water surface is
20 cm. When the temperature of water is
increased to 4°C, the height of the cylinder
above the water surface becomes 21 cm. The
density of water at T = 4°C, relative to the
density at T = 0°C is close to :
16
The graph which depicts the results of
Rutherford gold foil experiment with
$$\alpha $$-particales is :
$$\theta $$ : Scattering angle
Y : Number of scattered $$\alpha $$-particles detected (Plots are schematic and not to scale)
$$\theta $$ : Scattering angle
Y : Number of scattered $$\alpha $$-particles detected (Plots are schematic and not to scale)
17
A particle of mass m is fixed to one end of a
light spring having force constant k and
unstretched length $$\ell $$. The other end is fixed. The
system is given an angular speed $$\omega $$ about the
fixed end of the spring such that it rotates in a
circle in gravity free space. Then the stretch in
the spring is :
18
At time t = 0 magnetic field of 1000 Gauss is
passing perpendicularly through the area
defined by the closed loop shown in the figure.
If the magnetic field reduces linearly to
500 Gauss, in the next 5s, then induced EMF
in the loop is :
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19
Four resistances of 15$$\Omega $$, 12$$\Omega $$, 4$$\Omega $$ and 10$$\Omega $$
respectively in cyclic order to form
Wheatstone's network. The resistance that
is to be connected in parallel with the
resistance of 10$$\Omega $$ to balance the network is
_____$$\Omega $$.
20
Boolean relation at the output stage-Y for the
following circuit is :
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21
The magnifying power of a telescope with tube
60 cm is 5. What is the focal length of its eye
piece ?
22
A thermodynamic cycle xyzx is shown on a V-T diagram.
The P-V diagram that best describes this cycle
is :
(Diagrams are schematic and not to scale)
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(Diagrams are schematic and not to scale)
23
Photon with kinetic energy of 1MeV moves
from south to north. It gets an acceleration of
1012 m/s2 by an applied magnetic field (west to
east). The value of magnetic field : (Rest mass
of proton is 1.6 × 10–27 kg) :
24
The plot that depicts the behavior of the mean
free time t (time between two successive
collisions) for the molecules of an ideal gas, as
a function of temperature (T), qualitatively, is:
(Graphs are schematic and not drawn to scale)
(Graphs are schematic and not drawn to scale)