JEE Main 7 January 2020 Shift 1 Question Paper

Question 1

Let the function, $f:[-7,0]	o R$ be continuous on $[-7,0]$ and differentiable on $(-7,0)$. If $f(-7)=-3$ and $f'(x)\le 2$, for all $x\in(-7,0)$, then for all such functions f, $f(-1)+f(0)$ lies in the interval:

Accepted Answer

(B) $(-\infty, 20]$

Answer

(A) $[-3,11]$

Answer

(C) $[-6,20]$

Answer

(D) $(-\infty,11]$

Question 2

If the distance between the foci of an ellipse is 6 and the distance between its directrices is 12, then the length of its latus rectum is:

Accepted Answer

(B) $3\sqrt{2}$

Answer

(A) $\sqrt{3}$

Answer

(C) $\frac{3}{\sqrt{2}}$

Answer

(D) $2\sqrt{3}$

Question 3

An unbiased coin is tossed 5 time. Suppose that a variable X is assigned the value k when k consecutive heads are obtained for k = 3, 4, 5, otherwise X takes the value −1. Then the expected value of X, is

Accepted Answer

(C) $\frac{1}{8}$

Answer

(A) $-\frac{3}{16}$

Answer

(B) $-\frac{1}{8}$

Answer

(D) $\frac{3}{16}$

Question 4

Five numbers are in A.P., whose sum is 25 and product is 2520. If one of these five numbers is $-\frac{1}{2}$, then the greatest number amongst them is:

Accepted Answer

(C) 16

Answer

(A) 7

Answer

(B) $\frac{21}{2}$

Answer

(D) 27

Question 5

If the system of linear equations $2x+2ay+az=0$, $2x+3by+bz=0,2x+4cy+cz=0$ where a,b,c $\in R$ are non-zero and distinct; has a non-zero solution, then:

Accepted Answer

(C) $\frac{1}{a},\frac{1}{b},\frac{1}{c}$ are in A.P.

Answer

(A) $a+b+c=0$

Answer

(B) a, b, c are in A.P.

Answer

(D) a, b, c are in G.P.

Question 6

Let P be a plane passing through the points (2, 1, 0), (4, 1, 1) and (5, 0, 1) and R be any point (2, 1, 6). Then the image of R in the plane P is:

Accepted Answer

(C) (6, 5, −2)

Answer

(A) (6, 5, 2)

Answer

(B) (4, 3, 2)

Answer

(D) (3, 4, −2)

Question 7

If $Re\left(\frac{z-1}{2z+i}\right)=1$, where $z=x+iy$, then the point (x, y) lies on a:

Accepted Answer

(B) circle whose diameter is $\frac{\sqrt{5}}{2}$

Answer

(A) straight line whose slope is $\frac{3}{2}$

Answer

(C) straight line whose slope is $-\frac{2}{3}$

Answer

(D) circle whose centre is at $\left(-\frac{1}{2},-\frac{3}{2}\right)$

Question 8

If $y(\alpha)=\sqrt{2\left(\frac{	an\alpha+\cot\alpha}{1+	an^{2}\alpha}ight)+\frac{1}{\sin^{2}\alpha}}$, $\alpha\in\left(\frac{3\pi}{4},\piight)$ then $\frac{dy}{d\alpha}$ at $\alpha=\frac{5\pi}{6}$ is:

Accepted Answer

(A) 4

Answer

(B) $-\frac{1}{4}$

Answer

(C) −4

Answer

(D) $\frac{4}{3}$

Question 9

Let $\alpha$ be a root of the equation $x^{2}+x+1=0$ and the matrix $A=\frac{1}{\sqrt{3}}\begin{bmatrix} 1 & 1 & 1 \ 1 & \alpha & \alpha^{2} \ 1 & \alpha^{2} & \alpha^{4} \end{bmatrix}$, then the matrix $A^{31}$ is equal to:

Accepted Answer

(A) $A^{3}$

Answer

(B) A

Answer

(C) $I_{3}$

Answer

(D) $A^{2}$

Question 10

If $g(x)=x^{2}+x-1$ and $(gof)(x)=4x^{2}-10x+5$, then $f\left(\frac{5}{4}\right)$ is equal to

Accepted Answer

(D) $-\frac{1}{2}$

Answer

(A) $\frac{3}{2}$

Answer

(B) $\frac{1}{2}$

Answer

(C) $-\frac{3}{2}$

Question 11

If $y=mx+4$ is a tangent to both the parabolas, $y^{2}=4x$ and $x^{2}=2by$, then b is equal to:

Accepted Answer

(B) −128

Answer

(A) −32

Answer

(C) −64

Answer

(D) 128

Question 12

The logical statement $(p\Rightarrow q)\wedge(q\Rightarrow\sim p)$ is equivalent to:

Accepted Answer

(D) $\sim p$

Answer

(A) $\sim q$

Answer

(B) p

Answer

(C) q

Question 13

Let $x^{k} + y^{k} = a^{k}, (a,k > 0)$ and $\frac{dy}{dx} + \left(\frac{y}{x}\right)^{\frac{1}{3}} = 0$, then k is:

Accepted Answer

(D) $\frac{2}{3}$

Answer

(A) $\frac{3}{2}$

Answer

(B) $\frac{4}{3}$

Answer

(C) $\frac{1}{3}$

Question 14

Let $\alpha$ and $\beta$ be two real roots of the equation $(k+1)	an^{2}x - \sqrt{2}.\lambda 	an x = (1-k)$, where $k(
e -1)$ and $\lambda$ are real numbers. If $	an^{2}(\alpha+\beta) = 50$, then a value of $\lambda$ is:

Accepted Answer

(A) 10

Answer

(B) 5

Answer

(C) $5\sqrt{2}$

Answer

(D) $10\sqrt{2}$

Question 15

If $y = y(x)$ is the solution of the differential equation, $e^{y}\left(\frac{dy}{dx} - 1\right) = e^{x}$ such that $y(0) = 0$, then $y(1)$ is equal to:

Accepted Answer

(A) $1 + \log_{e} 2$

Answer

(B) $2e$

Answer

(C) $\log_{e} 2$

Answer

(D) $2 + \log_{e} 2$

Question 16

The area of the region, enclosed by the circle $x^{2} + y^{2} = 2$, which is not common to the region bounded by the parabola $y^{2} = x$ and the straight line $y = x$, is :

Accepted Answer

(C) $\frac{1}{6}(12\pi - 1)$

Answer

(A) $\frac{1}{3}(12\pi - 1)$

Answer

(B) $\frac{1}{3}(6\pi - 1)$

Answer

(D) $\frac{1}{6}(24\pi - 1)$

Question 17

A vector $\vec{a} = \alpha\hat{i} + 2\hat{j} + \beta\hat{k} \ (\alpha,\beta \in R)$ lies in the plane of the vectors, $\vec{b} = \hat{i} + \hat{j}$ and $\vec{c} = \hat{i} - \hat{j} + 4\hat{k}$. If $\vec{a}$ bisects the angle between $\vec{b}$ and $\vec{c}$, then:

Accepted Answer

(B) $\vec{a}.\hat{k} + 2 = 0$

Answer

(A) $\vec{a}.\hat{k} + 4 = 0$

Answer

(C) $\vec{a}.\hat{i} + 3 = 0$

Answer

(D) $\vec{a}.\hat{i} + 1 = 0$

Question 18

The greatest positive integer k, for which $49^{k}+1$ is a factor of the sum $49^{125} + 49^{124} + \ldots\ldots + 49^{2} + 49 + 1$, is:

Accepted Answer

(B) 63

Answer

(A) 65

Answer

(C) 32

Answer

(D) 60

Question 19

Total number of 6 - digit numbers in which only and all the five digits 1, 3, 5, 7 and 9 appear, is

Accepted Answer

(C) $\frac{5}{2}(6!)$

Answer

(A) $5^{6}$

Answer

(B) $6!$

Answer

(D) $\frac{1}{2}(6!)$

Question 20

Let S be the set of points where the function, $f(x) = \left|2 - |x-3|\right|, x \in R$, is not differentiable. Then $\sum\limits_{x \in S} f(f(x))$ is equal to _________.

Accepted Answer

3

Question 21

If the sum of the coefficients of all even powers of x in the product $(1+x+x^{2}+......+x^{2n})(1-x+x^{2}-x^{3}+.....+x^{2n})$ is 61, then n is equal to

Accepted Answer

30

Question 22

If the variance of the first n natural numbers is 10 and the variance of the first m even natural numbers is 16, then m + n is equal to _________

Accepted Answer

18

Question 23

$\lim\limits_{x 	o 2} \frac{3^{x}+3^{3-x}-12}{3^{-x/2}-3^{1-x}}$ is equal to _________

Accepted Answer

36

Question 24

Let $A(1,0), B(6,2)$ and $C\left(\frac{3}{2}, 6\right)$ be the vertices of a triangle ABC. If P is a point inside the triangle ABC such that the triangles APC, APB and BPC have equal areas, then the length of the line segment PQ, where Q is the point $\left(-\frac{7}{6}, -\frac{1}{3}\right)$ is _________

Accepted Answer

5

Question 25

A polarizer-analyser set is adjusted such that the intensity of light coming out of the analyser is just 10% of the original intensity. Assuming that the polarizer-analyser set does not absorb any light, the angle by which the analyser need to be rotated further to reduce the output intensity to be zero is

Accepted Answer

(A) $18.4°$

Answer

(B) $45°$

Answer

(C) $71.6°$

Answer

(D) $90°$

Question 26

Two infinite planes each with uniform surface charge density $+\sigma$ are kept in such a way that the angle between them is 30°. The electric field in the region shown between them is given by:

Accepted Answer

(A) $\dfrac{\sigma}{2\varepsilon_0}\left[\left(1-\dfrac{\sqrt{3}}{2}\right)\hat{y}-\dfrac{\hat{x}}{2}\right]$

Answer

(B) $\dfrac{\sigma}{2\varepsilon_0}\left[\left(1+\sqrt{3}\right)\hat{y}-\dfrac{\hat{x}}{2}\right]$

Answer

(C) $\dfrac{\sigma}{2\varepsilon_0}\left[\left(1+\sqrt{3}\right)\hat{y}+\dfrac{\hat{x}}{2}\right]$

Answer

(D) $\dfrac{\sigma}{\varepsilon_0}\left[\left(1+\dfrac{\sqrt{3}}{2}\right)\hat{y}+\dfrac{\hat{x}}{2}\right]$

Question 27

A long solenoid of radius R carries a time (t) dependent current I (t) = $I_0 t (1-t)$. A ring of radius 2R is placed cordially near its middle. During the time internal $0 \le t \le 1$, the induced current ($I_R$) and the induced EMF ($V_R$) in the ring changes as:

Accepted Answer

(D) At t = 0.5 direction of $I_R$ reverses and $V_R$ is zero.

Answer

(A) At t = 0.25 direction of $I_R$ reverses and $V_R$ is maximum.

Answer

(B) Direction of $I_R$ remains unchanged and $V_R$ is zero at t = 0.25

Answer

(C) Direction of $I_R$ remains unchanged and $V_R$ is maximum at t = 0.5

Question 28

Visible light of wavelength $6000 	imes 10^{-8}$ cm falls normally on a single slit and produces a diffraction pattern. It is found that the second diffraction minimum is at 60° from the central maximum. If the first minimum is produced at $	heta_1$ then $	heta_1$ is close to:

Accepted Answer

(C) $25°$

Answer

(A) $20°$

Answer

(B) $30°$

Answer

(D) $45°$

Question 29

A parallel plate capacitor has plates of area A separated by distance 'd' between them. It is filled with a dielectric which has a dielectric constant that varies as k(n) = k(1 + \alpha n) where 'x' is he distance measured from one of the plates.
If ($\alpha$d) << 1, the total capacitance of the system is best given by the expression:

Accepted Answer

(A) $\dfrac{AK\varepsilon_0}{d}\left(1+\dfrac{\alpha d}{2}\right)$

Answer

(B) $\dfrac{A\varepsilon_0 K}{d}\left(1+\dfrac{\alpha^2 d^2}{2}\right)$

Answer

(C) $\dfrac{AK\varepsilon_0}{d}(1+\alpha d)$

Answer

(D) $\dfrac{A\varepsilon_0 K}{d}\left[1+\left(\dfrac{\alpha d}{2}\right)^2\right]$

Question 30

The current $I_1$ (in A) flowing through 1 $\Omega$ resistor in the following circuit is

Accepted Answer

(C) 0.2

Answer

(A) 0.25

Answer

(B) 0.4

Answer

(D) 0.5

Question 31

The radius of gyration of a uniform rod of length $\ell$, about an axis passing through a point $\dfrac{\ell}{4}$ away from the centre of the rod, an perpendicular to it is:

Accepted Answer

(B) $\sqrt{\dfrac{7}{48}}\ell$

Answer

(A) $\dfrac{1}{8}\ell$

Answer

(C) $\dfrac{1}{4}\ell$

Answer

(D) $\sqrt{\dfrac{3}{8}}\ell$

Question 32

Three point particles of masses 10 kg, 1.5 kg and 2.5 kg are placed at there corners of a right angle triangle of sides 4.0 cm, 3.0 ;cm and 5.0 cm as shown in the figure. The centre of mass of the system is at a point:

Accepted Answer

(D) 0.9 cm right and 2.0 cm above 1 kg mass.

Answer

(A) 0.6 cm right and 2.0 cm above 1 kg mass.

Answer

(B) 2.0 cm right and 0.9 cm above 1 kg mass.

Answer

(C) 1.5 cm right and 1.2 cm above 1 kg mass.

Question 33

Consider a circular coil of wire carrying constant current I, forming a magnetic dipole. The magnetic flux through an infinite plane that contains the circular coil and excluding the circular coil area is given by $\phi$. The magnetic flux through the area is given by $\phi_0$. Which of the following is correct?

Accepted Answer

(A) $\phi_i=-\phi_0$

Answer

(B) $\phi_i>\phi_0$

Answer

(C) $\phi_i=\phi_0$

Answer

(D) $\phi_i<\phi_0$

Question 34

As shown in the figure, a bob of mass m is tied by a massless string whose other end portion is wound on a fly wheel (disc) of radius r and mass m. When released from rest the bob starts falling vertically. When it has covered a distance of h, the angular speed of the wheel will be

Accepted Answer

(D) $\dfrac{1}{r}\sqrt{\dfrac{4gh}{3}}$

Answer

(A) $r\sqrt{\dfrac{3}{4gh}}$

Answer

(B) $\dfrac{1}{r}\sqrt{\dfrac{2gh}{3}}$

Answer

(C) $r\sqrt{\dfrac{3}{2gh}}$

Question 35

If we need a magnification of 375 from a compound microscope of tube length 150 mm and an objective of focal length 5 mm, the focal length of the eye piece should be close to

Accepted Answer

(A) 22 mm

Answer

(B) 33 m

Answer

(C) 12 m

Answer

(D) 2 mm

Question 36

Two moles of an ideal gas with $\dfrac{C_P}{C_V}=\dfrac{5}{3}$ are mixed with 3 moles of another ideal gas with $\dfrac{C_P}{C_V}=\dfrac{4}{3}$. The value of $\dfrac{C_P}{C_V}$ for the mixture is:

Accepted Answer

(A) 1.42

Answer

(B) 1.47

Answer

(C) 1.45

Answer

(D) 1.50

Question 37

Speed of a transverse wave on a straight wire (mass 6.0 g, length 60 cm and area of cross-section 1.0 $mm^{2}$) is 90 $ms^{-1}$. If the young's modulus of wire is $16 	imes 10^{11}$ $Nm^{-2}$, the extension of wire over its natural length is:

Accepted Answer

(A) 0.03 mm

Answer

(B) 0.01 mm

Answer

(C) 0.02 mm

Answer

(D) 0.04 mm

Question 38

A litre of dry air at STP expands adiabatically to a volume of 3 litres. If γ = 1.40, the work done by air is: ($3^{1.4}$ = 4.6555) [Take air to be an ideal gas]

Accepted Answer

(B) 90.5 J

Answer

(A) 48 J

Answer

(C) 100.8 J

Answer

(D) 60.7 J

Question 39

A satellite of mass m is launched vertically upwards with an initial speed u from the surface of the earth. After it reaches height R (R = radius of the earth), it ejects a rocket of mass $\frac{m}{10}$ so that subsequently the satellite moves in a circular orbit. The kinetic energy of the rocket is (G is the gravitational constant ; M is the mass of the earth)

Accepted Answer

(D) $5m\left(u^{2}-\frac{119}{200}\frac{GM}{R}\right)$

Answer

(A) $\frac{m}{20}\left(u-\sqrt{\frac{2GM}{3R}}\right)^{2}$

Answer

(B) $\frac{3m}{8}\left(u+\sqrt{\frac{5GM}{6R}}\right)^{2}$

Answer

(C) $\frac{m}{20}\left(u^{2}-\frac{113}{200}\frac{GM}{R}\right)$

Question 40

The time period of revolution of electron in its ground state orbit in a hydrogen atom is $1.6 	imes 10^{-16}$ s. The frequency of revolution of the electron is its first excited state (in s$^{-1}$) is

Accepted Answer

(A) $7.8 	imes 10^{14}$

Answer

(B) $1.6 	imes 10^{14}$

Answer

(C) $6.2 	imes 10^{15}$

Answer

(D) $5.6 	imes 10^{12}$

Question 41

A LCR circuit behaves like a damped harmonic oscillator. Comparing it with a physical spring-mass damped oscillator having damping constant 'b', the connect equivalence would be:

Accepted Answer

(C) L $\leftrightarrow$ m, C $\leftrightarrow$ $\frac{1}{k}$, R $\leftrightarrow$ b

Answer

(A) L $\leftrightarrow$ $\frac{1}{b}$, C $\leftrightarrow$ $\frac{1}{m}$, R $\leftrightarrow$ $\frac{1}{k}$

Answer

(B) L $\leftrightarrow$ k, C $\leftrightarrow$ b, R $\leftrightarrow$ m

Answer

(D) L $\leftrightarrow$ m, C $\leftrightarrow$ k, R $\leftrightarrow$ b

Question 42

If the magnetic field in a plane electromagnetic wav is given by $\vec{B} = 3 	imes 10^{-8} \sin(1.6 	imes 10^{3} x + 48 	imes 10^{10} t)\hat{j}$ T, then what will be expression for electric field?

Accepted Answer

(C) $\vec{E} = \left(9 \sin(1.6 	imes 10^{3} x + 48 	imes 10^{10} t)\hat{k} 	ext{ V/m}ight)$

Answer

(A) $\vec{E} = \left(60 \sin(1.6 	imes 10^{3} x + 48 	imes 10^{10} t)\hat{k} 	ext{ V/m}ight)$

Answer

(B) $\vec{E} = \left(3 	imes 10^{-8} \sin(1.6 	imes 10^{3} x + 48 	imes 10^{10} t)\hat{i} 	ext{ V/m}ight)$

Answer

(D) $\vec{E} = \left(3 	imes 10^{-8} \sin(1.6 	imes 10^{3} x + 48 	imes 10^{10} t)\hat{j} 	ext{ V/m}ight)$

Question 43

Which of the following given a reversible operation?

Accepted Answer

(C) (C)

Answer

(A) (A)

Answer

(B) (B)

Answer

(D) (D)

Question 44

A 60 HP electric motor lifts an elevator having a maximum total load capacity of 2000 kg. If the frictional force on the elevator is 4000 N, the speed of the elevator at full load is close to: (1 HP = 746 W, g = 10 ms$^{-2}$)

Accepted Answer

(D) 1.9 m/s$^{-1}$

Answer

(A) 1.5 ms$^{-1}$

Answer

(B) 2.0 ms$^{-1}$

Answer

(C) 1.7 m/s$^{-1}$

Question 45

A Carnot engine operates between two reservoirs of temperatures 900 K and 300 K. The engine performs 1200 J of work per cycle. The heat energy (in J) delivered by the engine to the low temperature reservoir, in a cycle is _________.

Accepted Answer

600

Question 46

A loop ABCDEFA of straight edges has six corner points A (0, 0, 0), B (5, 0, 0), C(5, 5, 0), D(0, 5, 0), E(0, 5, 5) and F(0, 0, 5). The magnetic field in this region in $\vec{B} = (3\hat{i} + 4\hat{k})$T. The quantity of flux through the loop ABCDEFA (in Wb) is _________.

Accepted Answer

175

Question 47

A non-isotropic solid metal cube has coefficients of linear expansion as: $5 	imes 10^{-5}$/°C along the x = axis and $5 	imes 10^{-6}$/°C along the y and the z-axis. If coefficient of volume expansion of the solid C $	imes 10^{-6}$/°C then the value of C is _________.

Accepted Answer

60

Question 48

A particle (m = 1 kg) slides down a frictionless track (AOC) starting from rest of a point A (height 2 m). After reaching C, the particle continues to move freely in air as a projectile. When it leading its highest point P(height 1 m) the kinetic energy of the particle (in J) is: (Figure drawn is schematic and not to scale (take g = 10 ms$^{-2}$)

Accepted Answer

10

Question 49

A beam of electromagnetic radiation of intensity $6.4 	imes 10^{-5}$ W/cm$^{2}$ is comprised of wavelength, λ = 310 nm. It falls normally on a metal (work function φ = 2 eV) of surface area 1 cm$^{2}$. If one in $10^{3}$ photons ejects an electron, total number of electrons ejected in is $10^{x}$. ($h_c$ = 1240 eVnm, 1 eV = $1.6 	imes 10^{-19}$ J), then x is _________.

Accepted Answer

11

Question 50

The relative strength of interionic/intermolecular forces in decreasing order is

Accepted Answer

(C) ion-ion > ion-dipole > dipole-dipole

Answer

(A) ion-dipole > dipole-dipole > ion-ion

Answer

(B) dipole-dipole > ion-dipole > ion- ion

Answer

(D) ion-dipole > ion-ion > dipole-dipole

Question 51

Oxidation number of potassium in K$_2$O, K$_2$O$_2$ and KO$_2$ respectively is

Accepted Answer

(C) +1, +1 and +1

Answer

(A) +1, +2 and +4

Answer

(B) +2, +1 and +½

Answer

(D) +1, +4 and +2

Question 52

At 35°C, the vapour pressure of CS$_2$ is 512 mm of Hg and that of acetone is 344 mm of Hg. A solution of CS$_2$ in acetone has a total vapour pressure of 600 mm of Hg. The false statement among the following is

Accepted Answer

(D) a mixture of 100 mL CS$_2$ and 100 mL acetone has a volume of < 200 mL

Answer

(A) CS$_2$ and acetone are less attracted to each other than to themselves

Answer

(B) Heat must be absorbed in order to produce the solution at 35°C

Answer

(C) Raoult's law is not obeyed by this system

Question 53

The atomic radius of Ag is closest to

Accepted Answer

(C) Au

Answer

(A) Ni

Answer

(B) Cu

Answer

(D) Hg

Question 54

The dipole moments of CCl$_4$, CHCl$_3$ ad CH$_4$ are in the order

Accepted Answer

(C) CH$_4$ = CCl$_4$ < CHCl$_3$

Answer

(A) CHCl$_3$ < CH$_4$ = CCl$_4$

Answer

(B) CCl$_4$ < CH$_4$ < CHCl$_3$

Answer

(D) CH$_4$ < CCl$_4$ < CHCl$_3$

Question 55

In comparison to the zeolite process for the removal of permanent hardness, the synthetic resins method is

Accepted Answer

(D) more efficient as it can exchange both cation as well as anions

Answer

(A) less efficient as it exchanges  only anions

Answer

(B) more efficient as it can exchange only cations

Answer

(C) less efficient as the resin cannot be regenerated

Question 56

Amongst the following statements, that which was not proposed by Dalton was

Accepted Answer

(B) when gases combine or reproduced in a chemical reaction they do so in a simple ratio by volume provided all gases are at the same temperature & pressure

Answer

(A) matter consists of invisible atoms

Answer

(C) chemical reactions involve reorganisation of atoms. These are neither created nor destroyed in a chemical reaction

Answer

(D) All the atoms of a given element have identical properties including identical mass. Atoms of different elements differ in mass

Question 57

The increasing order of pK$_b$ for the following compounds will be
(a) NH$_2$-CH=NH$_2$          (b) [structure shown]          (c) CH$_3$NHCH$_3$

Accepted Answer

(C) b < a < c

Answer

(A) b < c < a

Answer

(B) c < a < b

Answer

(D) a < b < c

Question 58

What is the product of following reaction?
Hex − 3 − ynal $\xrightarrow[	ext{(ii) PBr}_3\ 	ext{(iii) Mg/ether}\ 	ext{(iv) CO}_2	ext{/H}_3	ext{O}^+]{	ext{(i) NaBH}_4}$ ?

Accepted Answer

(B) (B)

Answer

(A) (A)

Answer

(C) (C)

Answer

(D) (D)

Question 59

The number of orbitals associated with quantum number n = 5, m$_s$ = +$\frac{1}{2}$ is

Accepted Answer

(D) 25

Answer

(A) 15

Answer

(B) 11

Answer

(C) 50

Question 60

The purest form of commercial iron is

Accepted Answer

(B) wrought iron

Answer

(A) scrap iron and pig iron

Answer

(C) cast iron

Answer

(D) pig iron

Question 61

The theory that can completely/properly explain the nature of bonding in [Ni(CO)$_4$] is

Accepted Answer

(C) Molecular orbital theory

Answer

(A) Werner's theory

Answer

(B) Crystal field theory

Answer

(D) Valence bond theory

Question 62

The IUPAC name of the complex is [Pt(NH$_3$)$_2$Cl(NH$_2$CH$_3$)]Cl is

Accepted Answer

(B) Diamminechlorido(methanamine)platinum(II)chloride

Answer

(A) Diamminechlorido(aminomethane)platinum(II)chloride

Answer

(C) Diammine(methanamine)chlorido platinum(II)chloride

Answer

(D) Bisammine(methanamine)chloride platinum(II)chloride

Question 63

1-methyl ethylene oxide when treated with an excess of HBr, produces

Accepted Answer

(D) (D)

Answer

(A) (A)

Answer

(B) (B)

Answer

(C) (C)

Question 64

Consider the following reaction:

$\xrightarrow{OH^{-}}$ 'X'

The product 'X' is used

Accepted Answer

(D) in acid-base titration as an indicator

Answer

(A) in protein estimation as an alternative to ninhydrin

Answer

(B) as food grade colourant

Answer

(C) in laboratory test for phenols

Column – I	Column – II
i.Riboflamin	a.Beriberi
ii.Thiamine	b.Scurvy
iii.Pyridoxine	c.Cheilosis
iv.Ascorbic acid	d.Convulsions

JEE Main 7 January 2020 Shift 1 Question Paper with Answers

Physics — JEE Main 7 January 2020 Shift 1

Chemistry — JEE Main 7 January 2020 Shift 1

Mathematics — JEE Main 7 January 2020 Shift 1

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