JEE Main 2020 (Online) 5th September Evening Slot
Paper was held on Sat, Sep 5, 2020 9:30 AM
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Chemistry

1
The increasing order of boiling points of the following compounds is : JEE Main 2020 (Online) 5th September Evening Slot Chemistry - Basics of Organic Chemistry Question 207 English
2
Lattice enthalpy and enthalpy of solution of NaCl are 788 kJ mol–1, and 4 kJ mol–1, respectively.
The hydration enthalpy of NaCl is :
3
The rate constant (k) of a reaction is measured at differenct temperatures (T), and the data are plotted in the given figure. The activation energy of the reaction in kJ mol–1 is :
(R is gas constant) JEE Main 2020 (Online) 5th September Evening Slot Chemistry - Chemical Kinetics and Nuclear Chemistry Question 149 English
4
The compound that has the largest H–M–H bond angle (M = N, O, S, C) is :
5
Considering that $$\Delta $$0 > P, the magnetic moment
(in BM) of [Ru(H2O)6]2+ would be _________.
6
The correct order of the ionic radii of
O2–, N3–, F , Mg2+, Na+ and Al3+ is :
7
Consider the complex ions,
trans-[Co(en)2Cl2]+ (A) and
cis-[Co(en)2Cl2]+ (B).
The correct statement regarding them is :
8
For a reaction X + Y ⇌ 2Z , 1.0 mol of X, 1.5 mol
of Y and 0.5 mol of Z were taken in a 1 L vessel and
allowed to react. At equilibrium, the concentration
of Z was 1.0 mol L–1. The equilibrium constant of reaction
is $${x \over {15}}$$. The value of x is _________.
9
For a dimerization reaction,
2A(g) $$ \to $$ A2(g)
at 298 K, $$\Delta $$Uo = –20 kJ mol–1, $$\Delta $$So = –30 JK–1 mol–1,
then the $$\Delta $$Go will be _____ J.
10
Among the following compounds, geometrical isomerism is exhibited by :
11
The number of chiral carbons present in sucrose is _____.
12
The volume, in mL, of 0.02 M K2Cr2O7 solution required to react with 0.288 g of ferrous oxalate in acidic medium is _______.
(Molar mass of Fe = 56 g mol–1)
13
The final major product of the following reaction is : JEE Main 2020 (Online) 5th September Evening Slot Chemistry - Compounds Containing Nitrogen Question 190 English
14
Boron and silicon of very high purity can be obtained through :
15
The correct statement about probability density (except at infinite distance from nucleus) is :
16
The major product of the following reaction is : JEE Main 2020 (Online) 5th September Evening Slot Chemistry - Alcohols, Phenols and Ethers Question 127 English
17
The variation of molar conductivity with concentration of an electrolyte (X) in aqueous solution is shown in the given figure. JEE Main 2020 (Online) 5th September Evening Slot Chemistry - Electrochemistry Question 150 English
The electrolyte X is :
18
The major product formed in the following reaction is :
CH3CH = CHCH(CH3)2 $$\buildrel {HBr} \over \longrightarrow $$

Mathematics

1
The value of $${\left( {{{ - 1 + i\sqrt 3 } \over {1 - i}}} \right)^{30}}$$ is :
2
If the mean and the standard deviation of the
data 3, 5, 7, a, b are 5 and 2 respectively, then a and b are the roots of the equation :
3
If L = sin2$$\left( {{\pi \over {16}}} \right)$$ - sin2$$\left( {{\pi \over {8}}} \right)$$ and
M = cos2$$\left( {{\pi \over {16}}} \right)$$ - sin2$$\left( {{\pi \over {8}}} \right)$$, then :
4
$$\mathop {\lim }\limits_{x \to 0} {{x\left( {{e^{\left( {\sqrt {1 + {x^2} + {x^4}} - 1} \right)/x}} - 1} \right)} \over {\sqrt {1 + {x^2} + {x^4}} - 1}}$$
5
If the sum of the second, third and fourth terms of a positive term G.P. is 3 and the sum of its sixth, seventh and eighth terms is 243, then the sum of the first 50 terms of this G.P. is :
6
The derivative of
$${\tan ^{ - 1}}\left( {{{\sqrt {1 + {x^2}} - 1} \over x}} \right)$$ with
respect to $${\tan ^{ - 1}}\left( {{{2x\sqrt {1 - {x^2}} } \over {1 - 2{x^2}}}} \right)$$ at x = $${1 \over 2}$$ is :
7
There are 3 sections in a question paper and each section contains 5 questions. A candidate has to answer a total of 5 questions, choosing at least one question from each section. Then the number of ways, in which the candidate can choose the questions, is :
8
If
$$\int {{{\cos \theta } \over {5 + 7\sin \theta - 2{{\cos }^2}\theta }}} d\theta $$ = A$${\log _e}\left| {B\left( \theta \right)} \right| + C$$,

where C is a constant of integration, then $${{{B\left( \theta \right)} \over A}}$$
can be :
9
If the length of the chord of the circle,
x2 + y2 = r2 (r > 0) along the line, y – 2x = 3 is r,
then r2 is equal to :
10
If x = 1 is a critical point of the function
f(x) = (3x2 + ax – 2 – a)ex , then :
11
The area (in sq. units) of the region

A = {(x, y) : (x – 1)[x] $$ \le $$ y $$ \le $$ 2$$\sqrt x $$, 0 $$ \le $$ x $$ \le $$ 2}, where [t]

denotes the greatest integer function, is :
12
Let y = y(x) be the solution of the differential equation

cosx$${{dy} \over {dx}}$$ + 2ysinx = sin2x, x $$ \in $$ $$\left( {0,{\pi \over 2}} \right)$$.

If y$$\left( {{\pi \over 3}} \right)$$ = 0, then y$$\left( {{\pi \over 4}} \right)$$ is equal to :
13
Let the vectors $$\overrightarrow a $$, $$\overrightarrow b $$, $$\overrightarrow c $$ be such that
$$\left| {\overrightarrow a } \right| = 2$$, $$\left| {\overrightarrow b } \right| = 4$$ and $$\left| {\overrightarrow c } \right| = 4$$. If the projection of
$$\overrightarrow b $$ on $$\overrightarrow a $$ is equal to the projection of $$\overrightarrow c $$ on $$\overrightarrow a $$
and $$\overrightarrow b $$ is perpendicular to $$\overrightarrow c $$, then the value of
$$\left| {\overrightarrow a + \vec b - \overrightarrow c } \right|$$ is ___________.
14
If $$\alpha $$ and $$\beta $$ are the roots of the equation,
7x2 – 3x – 2 = 0, then the value of
$${\alpha \over {1 - {\alpha ^2}}} + {\beta \over {1 - {\beta ^2}}}$$ is equal to :
15
If the system of linear equations
x + y + 3z = 0
x + 3y + k2z = 0
3x + y + 3z = 0
has a non-zero solution (x, y, z) for some k $$ \in $$ R, then x + $$\left( {{y \over z}} \right)$$ is equal to :
16
Let A = {a, b, c} and B = {1, 2, 3, 4}. Then the number of elements in the set
C = {f : A $$ \to $$ B | 2 $$ \in $$ f(A) and f is not one-one} is ______.
17
If a + x = b + y = c + z + 1, where a, b, c, x, y, z
are non-zero distinct real numbers, then
$$\left| {\matrix{ x & {a + y} & {x + a} \cr y & {b + y} & {y + b} \cr z & {c + y} & {z + c} \cr } } \right|$$ is equal to :

Physics

1
A ring is hung on a nail. It can oscillate, without slipping or sliding
(i) in its plane with a time period T1 and,
(ii) back and forth in a direction perpendicular to its plane,
with a period T2. The ratio $${{{T_1}} \over {{T_2}}}$$ will be :
2
An infinitely long, straight wire carrying current I, one side opened rectangular loop and a conductor C with a sliding connector are located in the same plane, as shown, in the figure. The connector has length $$l$$ and resistance R. It slides to the right with a velocity v. The resistance of the conductor and the self inductance of the loop are negligible. The induced current in the loop, as a function of separation r, between the connector and the straight wire is : JEE Main 2020 (Online) 5th September Evening Slot Physics - Electromagnetic Induction Question 102 English
3
An iron rod of volume 10–3 m3 and relative permeability 1000 is placed as core in a solenoid with 10 turns/cm. If a current of 0.5 A is passed through the solenoid, then the magnetic moment of the rod will be :
4
In an experiment to verify Stokes law, a small spherical ball of radius r and density $$\rho $$ falls under gravity through a distance h in air before entering a tank of water. If the terminal velocity of the ball inside water is same as its velocity just before entering the water surface, then the value of h is proportional to :
(ignore viscosity of air)
5
A spaceship in space sweeps stationary interplanetary dust. As a result, its mass
increases at a rate $${{dM\left( t \right)} \over {dt}}$$ = bv2(t), where v(t) is its instantaneous velocity. The instantaneous acceleration of the satellite is :
6
In an adiabatic process, the density of a diatomic gas becomes 32 times its initial value. The final pressure of the gas is found to be n times the initial pressure. The value of n is :
7
The quantities x = $${1 \over {\sqrt {{\mu _0}{\varepsilon _0}} }}$$, y = $${E \over B}$$ and z = $${l \over {CR}}$$ are
defined where C-capacitance, R-Resistance, l-length, E-Electric field, B-magnetic field and $${{\varepsilon _0}}$$, $${{\mu _0}}$$, - free space permittivity and permeability respectively. Then :
8
A body of mass 2 kg is driven by an engine delivering a constant power of 1 J/s. The body starts from rest and moves in a straight line. After 9 seconds, the body has moved a distance (in m) _______.
9
Two different wires having lengths L1 and L2, and respective temperature coefficient of linear expansion $$\alpha $$1 and $$\alpha $$2, are joined end-to-end. Then the effective temperature coefficient of linear expansion is :
10
The correct match between the entries in column I and column II are :

I II
Radiation Wavelength
(a) Microwave (i) 100 m
(b) Gamma rays (ii) 10–15 m
(c) A.M. radio waves (iii) 10–10 m
(d) X-rays (iv) 10–3 m
11
The surface of a metal is illuminated alternately with photons of energies E1 = 4 eV and E2 = 2.5 eV respectively. The ratio of maximum speeds of the photoelectrons emitted in the two cases is 2. The work function of the metal in (eV) is _____.
12
Two coherent sources of sound, S1 and S2, produce sound waves of the same wavelength, $$\lambda $$ = 1 m, in phase. S1 and S2 are placed 1.5 m apart (see fig). A listener, located at L, directly in front of S2 finds that the intensity is at a minimum
when he is 2 m away from S2. The listener moves away from S1, keeping his distance from S2 fixed. The adjacent maximum of intensity is observed when the listener is at a distance d from S1. Then, d is : JEE Main 2020 (Online) 5th September Evening Slot Physics - Wave Optics Question 123 English
13
The acceleration due to gravity on the earth’s surface at the poles is g and angular velocity of the earth about the axis passing through the pole is $$\omega $$. An object is weighed at the equator and at a height h above the poles by using a spring balance. If the weights are found to be same, then h is (h << R, where R is the radius of the earth)
14
In the circuit shown, charge on the 5 $$\mu $$F capacitor is :

JEE Main 2020 (Online) 5th September Evening Slot Physics - Capacitor Question 113 English
15
Ten charges are placed on the circumference of a circle of radius R with constant angular separation between successive charges. Alternate charges 1, 3, 5, 7, 9 have charge (+q) each, while 2, 4, 6, 8, 10 have charge (–q) each. The potential V and the electric field E at the centre of the circle are respectively.
(Take V = 0 at infinity)
16
Nitrogen gas is at 300oC temperature. The temperature (in K) at which the rms speed of a H2 molecule would be equal to the rms speed of a nitrogen molecule, is _______.
(Molar mass of N2 gas 28 g).
17
A galvanometer is used in laboratory for detecting the null point in electrical experiments. If, on passing a current of 6 mA it produces a deflection of 2o, its figure of merit is close to :
18
In the circuit, given in the figure currents in different branches and value of one resistor are shown. Then potential at point B with respect to the point A is : JEE Main 2020 (Online) 5th September Evening Slot Physics - Current Electricity Question 247 English
19
A prism of angle A = 1o has a refractive index $$\mu $$ = 1.5. A good estimate for the minimum angle of deviation (in degrees) is close to $${N \over {10}}$$.
Value of N is ____.
20
The velocity (v) and time (t) graph of a body in a straight line motion is shown in the figure. The point S is at 4.333 seconds. The total distance covered by the body in 6 s is : JEE Main 2020 (Online) 5th September Evening Slot Physics - Motion in a Straight Line Question 88 English
21
A parallel plate capacitor has plate of length 'l', width ‘w’ and separation of plates is ‘d’. It is connected to a battery of emf V. A dielectric slab of the same thickness ‘d’ and of dielectric constant k = 4 is being inserted between the plates of the capacitor. At what length of the slab inside plates, will the energy stored in the capacitor be two times the initial energy stored?
22
Two Zener diodes (A and B) having breakdown voltages of 6 V and 4 V respectively, are connected as shown in the circuit below. The output voltage V0 variation with input voltage linearly increasing with time, is given by :
(Vinput = 0 V at t = 0)
(figures are qualitative) JEE Main 2020 (Online) 5th September Evening Slot Physics - Semiconductor Question 162 English
23
A thin rod of mass 0.9 kg and length 1 m is suspended, at rest, from one end so that it can freely oscillate in the vertical plane. A particle of move 0.1 kg moving in a straight line with velocity 80 m/s hits the rod at its bottom most point and sticks to it (see figure). The angular speed (in rad/s) of the rod immediately after the collision will be _________. JEE Main 2020 (Online) 5th September Evening Slot Physics - Rotational Motion Question 160 English