JEE Main 2019 (Online) 8th April Morning Slot
Paper was held on Mon, Apr 8, 2019 3:30 AM
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Chemistry

1
In order to oxidise a mixture of one mole of each of FeC2O4, Fe2(C2O4)3, FeSO4 and Fe2(SO4)3 in acidic medium, the number of moles of KMnO4 required is :
2
The following ligand is : JEE Main 2019 (Online) 8th April Morning Slot Chemistry - Coordination Compounds Question 291 English
3
The major product of the following reaction is : JEE Main 2019 (Online) 8th April Morning Slot Chemistry - Aldehydes, Ketones and Carboxylic Acids Question 228 English
4
Which one of the following equations does not correctly represent the first law of thermodynamics for the given processes involving an ideal gas? (Assume non-expansion work is zero)
5
Given that $${E^\Theta }_{{O_2}/{H_2}O} = 1.23\,V$$ ;

$${E^\Theta }_{{S_2}O_8^{2 - }/SO_4^{2 - }} = 2.05\,V$$

$${E^\Theta }_{B{r_2}/B{r^ - }} = 1.09\,V$$

$${E^\Theta }_{A{u^{3 + }}/Au} = 1.4\,V$$

The strongest oxidizing agent is :
6
Which of the following amines can be prepared by Gabriel phthalimide reaction ?
7
If solublity product of Zr3(PO4)4 is denoted by Ksp and its molar solubility is denoted by S, then which of the following relation between S and Ksp is correct ?
8
For the reaction 2A + B $$ \to $$ C, the values of initial rate at diffrent reactant concentrations are given in the table below. The rate law for the reaction is :

[A] (mol L-1) [B] (mol L-1) Initial Rate (mol L-1s-1)
0.05 0.05 0.045
0.10 0.05 0.090
0.20 0.10 0.72
9
The size of the iso-electronic species Cl,  Ar and Ca2+ is affected by :
10
The lathanide ion that would show colour is :
11
The major product of the following reaction is : JEE Main 2019 (Online) 8th April Morning Slot Chemistry - Alcohols, Phenols and Ethers Question 145 English
12
The correct order of the spin-only magnetic moment of metal ions in the following low-spin complexes, [V(CN)6]4–,[Fe(CN)6]4–, [Ru(NH3)6]3+, and [Cr(NH3)6]2+ , is :
13
The major product of the following reaction is : JEE Main 2019 (Online) 8th April Morning Slot Chemistry - Aldehydes, Ketones and Carboxylic Acids Question 229 English
14
For silver, Cp(J K–1 mol–1) = 23 +0.01 T. If the temperature (T) of 3 moles of silver is raised from 300 K to 1000 K at 1 atm pressure, the value of $$\Delta H$$ will be close to :
15
An organic compound neither reacts with neutral ferric chloride solution nor with fehling solution. it however, reacts with Grignard reagent and gives positive iodoform test. The compound is :
16
Maltose on treatment with dilute HCI gives :
17
In the following compounds, the decreasing order of basic strength will be :
18
The quantum number of four electrons are given below :
n = 4, l = 2, ml =–2, ms = –1/2
n = 3, l = 2, ml = 1, ms = +1/2
n = 4, l = 1, ml = 0, ms = +1/2
n = 3, l = 1, ml = 1, ms = –1/2
The correct order of their increasing enegies will be :
19
The vapour pressures of pure liquids A and B are 400 and 600 mmHg, respectively at 298 K on mixing the two liquids, the sum of their initial volume is equal ot the volume of the final mixture. The mole fraction of liquid B is 0.5 in the mixture, The vapour pressure of the final solution, the mole fractions of components A and B in vapour phase, respectively are :
20
An organic compound 'X' showing the following solubility profile is : JEE Main 2019 (Online) 8th April Morning Slot Chemistry - Practical Organic Chemistry Question 99 English
21
The IUPAC name of the following compound is :
JEE Main 2019 (Online) 8th April Morning Slot Chemistry - Basics of Organic Chemistry Question 231 English
22
Coupling of benzene diazonium chloride with 1 - naphthol in alkaline medium will give :

Mathematics

1
If $$f(x) = {{2 - x\cos x} \over {2 + x\cos x}}$$ and g(x) = logex, (x > 0) then the value of integral

$$\int\limits_{ - {\pi \over 4}}^{{\pi \over 4}} {g\left( {f\left( x \right)} \right)dx{\rm{ }}} $$ is
2
$$\int {{{\sin {{5x} \over 2}} \over {\sin {x \over 2}}}dx} $$ is equal to
(where c is a constant of integration)
3
$$\mathop {\lim }\limits_{x \to 0} {{{{\sin }^2}x} \over {\sqrt 2 - \sqrt {1 + \cos x} }}$$ equals:
4
The area (in sq. units) of the region
A = { (x, y) $$ \in $$ R × R|  0 $$ \le $$ x $$ \le $$ 3, 0 $$ \le $$ y $$ \le $$ 4, y $$ \le $$ x2 + 3x} is :
5
Let A and B be two non-null events such that A $$ \subset $$ B . Then, which of the following statements is always correct?
6
Let y = y(x) be the solution of the differential equation,

$${({x^2} + 1)^2}{{dy} \over {dx}} + 2x({x^2} + 1)y = 1$$

such that y(0) = 0. If $$\sqrt ay(1)$$ = $$\pi \over 32$$ , then the value of 'a' is :
7
The sum of all natural numbers 'n' such that 100 < n < 200 and H.C.F. (91, n) > 1 is :
8
Let $$A = \left( {\matrix{ {\cos \alpha } & { - \sin \alpha } \cr {\sin \alpha } & {\cos \alpha } \cr } } \right)$$, ($$\alpha $$ $$ \in $$ R)
such that $${A^{32}} = \left( {\matrix{ 0 & { - 1} \cr 1 & 0 \cr } } \right)$$ then a value of $$\alpha $$ is
9
The sum of the solutions of the equation
$$\left| {\sqrt x - 2} \right| + \sqrt x \left( {\sqrt x - 4} \right) + 2 = 0$$
(x > 0) is equal to:
10
Let ƒ : [0, 2] $$ \to $$ R be a twice differentiable function such that ƒ''(x) > 0, for all x $$ \in $$ (0, 2). If $$\phi $$(x) = ƒ(x) + ƒ(2 – x), then $$\phi $$ is :
11
The length of the perpendicular from the point (2, –1, 4) on the straight line,

$${{x + 3} \over {10}}$$= $${{y - 2} \over {-7}}$$ = $${{z} \over {1}}$$ is :
12
If $$\alpha $$ and $$\beta $$ be the roots of the equation x2 – 2x + 2 = 0, then the least value of n for which $${\left( {{\alpha \over \beta }} \right)^n} = 1$$ is :
13
If $$f(x) = {\log _e}\left( {{{1 - x} \over {1 + x}}} \right)$$, $$\left| x \right| < 1$$ then $$f\left( {{{2x} \over {1 + {x^2}}}} \right)$$ is equal to
14
Let O(0, 0) and A(0, 1) be two fixed points. Then the locus of a point P such that the perimeter of $$\Delta $$AOP is 4, is :
15
If $$\alpha = {\cos ^{ - 1}}\left( {{3 \over 5}} \right)$$, $$\beta = {\tan ^{ - 1}}\left( {{1 \over 3}} \right)$$ where $$0 < \alpha ,\beta < {\pi \over 2}$$ , then $$\alpha $$ - $$\beta $$ is equal to :
16
All possible numbers are formed using the digits 1, 1, 2, 2, 2, 2, 3, 4, 4 taken all at a time. The number of such numbers in which the odd digits occupy even places is :
17
The mean and variance of seven observations are 8 and 16, respectively. If 5 of the observations are 2, 4, 10, 12, 14, then the product of the remaining two observations is :
18
The greatest value of c $$ \in $$ R for which the system of linear equations
x – cy – cz = 0
cx – y + cz = 0
cx + cy – z = 0
has a non-trivial solution, is :
19
If cos($$\alpha $$ + $$\beta $$) = 3/5 ,sin ( $$\alpha $$ - $$\beta $$) = 5/13 and 0 < $$\alpha , \beta$$ < $$\pi \over 4$$, then tan(2$$\alpha $$) is equal to :
20
If S1 and S2 are respectively the sets of local minimum and local maximum points of the function,

ƒ(x) = 9x4 + 12x3 – 36x2 + 25, x $$ \in $$ R, then :
21
If $$2y = {\left( {{{\cot }^{ - 1}}\left( {{{\sqrt 3 \cos x + \sin x} \over {\cos x - \sqrt 3 \sin x}}} \right)} \right)^2}$$,

x $$ \in $$ $$\left( {0,{\pi \over 2}} \right)$$ then $$dy \over dx$$ is equal to:
22
The sum of the squares of the lengths of the chords intercepted on the circle, x2 + y2 = 16, by the lines, x + y = n, n $$ \in $$ N, where N is the set of all natural numbers, is :
23
A point on the straight line, 3x + 5y = 15 which is equidistant from the coordinate axes will lie only in :

Physics

1
An upright object is placed at a distance of 40 cm in front of a convergent lens of focal length 20 cm. A convergent mirror of focal length 10 cm is placed at a distance of 60 cm on the other side of the lens. The position and size of the final image will be :
2
Two particles move at right angle to each other. Their de-Broglie wavelengths are $$\lambda _1$$ and $$\lambda _2$$ respectively. The particles suffer perfectly inelastic collision. The de-Broglie wavelength $$\lambda _2$$ of the final particle, is given by :
3
A thermally insulated vessel contains 150g of water at 0°C. Then the air from the vessel is pumped out adiabatically. A fraction of water turns into ice and the rest evaporates at 0°C itself. The mass of evaporated water will be closest to : (Latent heat of vaporization of water = 2.10 × 106 J kg–1 and Latent heat of Fusion of water = 3.36 × 105 J kg–1)
4
A thin circular plate of mass M and radius R has its density varying as $$\rho $$(r) = $$\rho $$0r with $$\rho $$0 as constant and r is the distance from its centre. The moment of Inertia of the circular plate about an axis perpendicular to the plate and passing through its edge is I = aMR2. The value of the coefficient a is :
5
If 1022 gas molecules each of mass 10–26 kg collide with a surface (perpendicular to it) elastically per second over an area 1 m2 with a speed 104 m/s, the pressure exerted by the gas molecules will be of the order of :
6
A thin strip 10 cm long is on a U shaped wire of negligible resistance and it is connected to a spring of spring constant 0.5 Nm–1 (see figure). The assembly is kept in a uniform magnetic field of 0.1 T. If the strip is pulled from its equilibrium position and released, the number of oscillation it performs before its amplitude decreases by a factor of e is N. If the mass of the strip is 50 grams, its resistance 10W and air drag negligible, N will be close to : JEE Main 2019 (Online) 8th April Morning Slot Physics - Magnetic Effect of Current Question 185 English
7
An alternating voltage v(t) = 220 sin 100 $$\pi $$t volt is applied to a purely resistance load of 50$$\Omega $$ . The time taken for the current to rise from half of the peak value to the peak value is :
8
In an interference experiment the ratio of amplitudes of coherent waves is $${{{a_1}} \over {{a_2}}} = {1 \over 3}$$ . The ratio of maximum and minimum intensities of fringes will be :
9
In figure, the optical fiber is $$l$$ = 2m long and has a diameter of d = 20 μm. If a ray of light is incident on one end of the fiber at angle $$\theta _1$$ = 40°, the number of reflection it makes before emerging from the other end is close to: (refractive index of fibre is 1.31 and sin 40° = 0.64) JEE Main 2019 (Online) 8th April Morning Slot Physics - Geometrical Optics Question 221 English
10
The bob of a simple pendulum has mass 2g and a charge of 5.0 μC. It is at rest in a uniform horizontal electric field of intensity 2000 V/m. At equilibrium, the angle that the pendulum makes with the vertical is : (take g = 10 m/s2)
11
Ship A is sailing towards north-east with velocity $$\mathop v\limits^ \to = 30\mathop i\limits^ \wedge + 50\mathop j\limits^ \wedge $$ km/hr where $$\mathop i\limits^ \wedge $$ points east and $$\mathop j\limits^ \wedge $$ , north. Ship B is at a distance of 80 km east and 150 km north of Ship A and is sailing towards west at 10 km/hr. A will be at minimum distance from B in :
12
Water from a pipe is coming at a rate of 100 litres per minute. If the radius of the pipe is 5 cm, the Reynolds number for the flow is of the order of : (density of water = 1000 kg/m3, coefficient of viscosity of water = 1mPas)
13
Four particles A, B, C and D with masses mA = m, mB = 2m, mC = 3m and mD = 4m are at the corners of a square. They have accelerations of equal magnitude with directions as shown. The acceleration of the centre of mass of the particles is : JEE Main 2019 (Online) 8th April Morning Slot Physics - Center of Mass and Collision Question 102 English
14
A plane electromagnetic wave travels in free space along the x-direction. The electric field component of the wave at a particular point of space and time is E = 6 V m–1 along y-direction. Its corresponding magnetic field component, B would be :
15
Four identical particles of mass M are located at the corners of a square of side 'a'. What should be their speed if each of them revolves under the influence of other's gravitational field in a circular orbit circumscribing the square? JEE Main 2019 (Online) 8th April Morning Slot Physics - Gravitation Question 170 English
16
A particle moves in one dimension from rest under the influence of a force that varies with the distance travelled by the particle as shown in the figure. The kinetic energy of the particle after it has travelled 3m is : JEE Main 2019 (Online) 8th April Morning Slot Physics - Work Power & Energy Question 115 English
17
JEE Main 2019 (Online) 8th April Morning Slot Physics - Waves Question 110 English A wire of length 2L, is made by joining two wires A and B of same length but different radii r and 2r and made of the same material. It is vibrating at a frequency such that the joint of the two wires forms a node. If the number of antinodes in wire A is p and that in B is q then the ratio p : q is :
18
Radiation coming from transitions n = 2 to n = 1 of hydrogen atoms fall on He+ ions in n = 1 and n = 2 states. The possible transition of helium ions as they absorb energy from the radiation is :
19
In SI units, the dimensions of $$\sqrt {{{{ \in _0}} \over {{\mu _0}}}} $$ is :
20
A 20 Henry inductor coil is connected to a 10 ohm resistance in series as shown in figure. The time at which rate of dissipation of energy (joule's heat) across resistance is equal to the rate at which magnetic energy is stored in the inductor is : JEE Main 2019 (Online) 8th April Morning Slot Physics - Electromagnetic Induction Question 119 English
21
Voltage rating of a parallel plate capacitor is 500V. Its dielectric can withstand a maximum electric field of 106 V/m. The plate area is 10–4 m2. What is the dielectric constant is the capacitance is 15 pF? (given $$\varepsilon $$0 = 8.86 × 10–12 C2/Nm2)
22
A boy's catapult is made of rubber cord which is 42 cm long, with 6 mm diameter of cross-section and of negligible mass. The boy keeps a stone weighing 0.02kg on it and stretches the cord by 20 cm by applying a constant force. When released, the stone flies off with a velocity of 20 ms–1. Neglect the change in the area of cross-section of the cord while stretched. The Young's modulus of rubber is closest to:
23
Two identical beakers A and B contain equal volumes of two different liquids at 60°C each and left to cool down. Liquid in A has density of 8 × 102 kg/m3 and specific heat of 2000 J kg–1 K–1 while liquid in B has density of 103 kg m–3 and specific heat of 4000 J kg–1 K–1. Which of the following best describes their temperature versus time graph schematically? (assume the emissivity of both the beakers to be the same)
24
A solid conducting sphere, having a charge Q, is surrounded by an uncharged conducting hollow spherical shell. Let the potential difference between the surface of the solid sphere and that of the outer surface of the hollow shell be V. If the shell is now given a charge of –4 Q, the new potential difference between the same two surfaces is :
25
The reverse breakdown voltage of a Zener diode is 5.6 V in the given circuit.

The current IZ through the Zener is : JEE Main 2019 (Online) 8th April Morning Slot Physics - Semiconductor Question 186 English
26
A circular coil having N turns and radius r carries a current I. It is held in the XZ plane in a magnetic field B$${\mathop i\limits^ \wedge }$$ . The torque on the coil due to the magnetic field is :
27
A steel wire having a radius of 2.0 mm, carrying a load of 4 kg, is hanging from a ceiling. Given that g = 3.1 p ms–2, what will be the tensile stress that would be developed in the wire ?
28
For the circuit shown, with R1 = 1.0W, R2 = 2.0 W, E1 = 2 V and E2 = E3 = 4 V, the potential difference between the points 'a' and 'b' is approximately (in V): JEE Main 2019 (Online) 8th April Morning Slot Physics - Current Electricity Question 284 English