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JEE Main 2021 (16 Mar Shift 1)

2021 · 90 questions · First 10 Solutions Free
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Q1 mcq
The maximum and minimum distances of a comet from the Sun are $1. 6 \times 10^{12}\,m$ and $8. 0 \times 10^{10}\,m$ respectively. If the speed of the comet at the nearest point is $6 \times 10^{4}\,m\,s^{-1}$ , the speed at the farthest point is
a.
$1. 5 \times 10^{3}\,m\,s^{-1}$
b.
$6. 6 \times 10^{3}\,m\,s^{-1}$
c.
$3. 0 \times 10^{3}\,m\,s^{-1}$ Correct Answer
d.
$4. 5 \times 10^{3}\,m\,s^{-1}$

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Q2 mcq
A bar magnet of length $14\, cm$ is placed in the magnetic meridian with its north pole pointing towards the geographic north pole. A neutral point is obtained at a distance of $18\, cm$ from the center of the magnet. If $B_{H} = 0. 4\,G$ , the magnetic moment of the magnet is $(1\,G = 10^{-4}\,T)$
a.
$2. 880 \times 10^{3}\,J\,T^{-1}$
b.
$2. 880 \times 10^{2}\,J\,T^{-1}$
c.
$2. 880\,J\,T^{-1}$ Correct Answer
d.
$28. 80\,J\,T^{-1}$

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Q3 nat
The resistance $R= \frac{V}{I}$ , where $V = (50 \pm 2)\,V$ and $I = (20 \pm 0. 2)\,A$ . The percentage error in $R$ is $x%$ . The value of $x$ to the nearest integer is ________.
✓ Accepted Answer: 5

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Q4 mcq
For an electromagnetic wave travelling in free space, the relation between average energy densities due to electric $(U_{e})$ and magnetic $(U_{m})$ fields is :
a.
$U_{e} =U_{m}$ Correct Answer
b.
$U_{e} >U_{m}$
c.
$U_{e} <U_{m}$
d.
$U_{e} \neq U_{m}$

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Q5 mcq
The volume $V$ of an enclosure contains a mixture of three gases, $16\,g$ of oxygen, $28\,g$ of nitrogen and $44\,g$ of carbon dioxide at absolute temperature $T$ . Consider $R$ as universal gas constant. The pressure of the mixture of gases is :
a.
$\frac{88RT}{V}$
b.
$\frac{3RT}{V}$
c.
$\frac{5}{2} \frac{RT}{V}$ Correct Answer
d.
$\frac{4RT}{V}$

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Q6 mcq
A block of $200\,g$ mass moves with a uniform speed in a horizontal circular groove, with vertical side walls of radius $20\, cm$ . If the block takes $40\,s$ to complete one round, the normal force by the side walls of the groove is:
a.
$0. 0314\,N$
b.
$9. 859 \times 10^{-2}\,N$
c.
$6. 28 \times 10^{-3}\,N$
d.
$9. 859 \times 10^{-4}\,N$ Correct Answer

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Q7 mcq
Four equal masses, $m$ each are placed at the corners of a square of length $(l)$ as shown in the figure. The moment of inertia of the system about an axis passing through $A$ and parallel to $DB$ would be :
a.
$ml^{2}$
b.
$2\,ml^{2}$
c.
$3\,ml^{2}$ Correct Answer
d.
$\sqrt{3}\,ml^{2}$

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Q8 mcq
The angle of deviation through a prism is minimum when (A) Incident ray and emergent ray are symmetric to the prism (B) The refracted ray inside the prism becomes parallel to its base (C) Angle of incidence is equal to that of the angle of emergence (D) When angle of emergence is double the angle of incidence Choose the correct answer from the options given below :
Question 8 image
a.
Statements (A),(B) and (C) are true Correct Answer
b.
Only statement (D) is true
c.
Only statements (A) and (B) are true
d.
Statements (B) and (C) are true

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Q9 mcq
An $RC$ circuit as shown in the figure is driven by a $AC$ source generating a square wave. The output wave pattern monitored by $CRO$ would look close to :
Question 9 image

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Q10 nat
Consider a $20\, kg$ uniform circular disk of radius $0. 2\,m$ . It is pin supported at its center and is at rest initially. The disk is acted upon by a constant force $F = 20\,N$ through a massless string wrapped around its periphery as shown in the figure. Suppose the disk makes $n$ number of revolutions to attain an angular speed of $50\, rad \,s^{-1}$ . The value of $n$ , to the nearest integer, is _______ . [Given : In one complete revolution, the disk rotates by $6. 28\, rad$ ]
Question 10 image
✓ Accepted Answer: 20

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Q11 nat
A sinusoidal voltage of peak value $250\,V$ is applied to a series $LCR$ circuit, in which $R= 8\,\Omega ,L= 24\, mH$ and $C = 60\,\mu F$ . The value of power dissipated at resonant condition is $xkW$ . The value of $x$ to the nearest integer is _______.
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Q12 nat
Consider a frame that is made up of two thin massless rods $AB$ and $AC$ as shown in the figure. A vertical force $\vec{P}$ of magnitude $100\,N$ is applied at point $A$ of the frame. Suppose the force is $\vec{P}$ resolved parallel to the arms $AB$ and $AC$ of the frame. The magnitude of the resolved component along the arm $AC$ is $xN$ . The value of $x$ , to the nearest integer, is ________. [Given : $sin(35^{\circ}) = 0. 573, cos(35^{\circ}) = 0. 819, \, sin(110^{\circ}) = 0. 939, cos(110^{\circ}) = -0. 342$ ]
Question 12 image
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Q13 nat
The first three spectral lines of $H$ -atom in the Balmer series are given $\lambda _{1},\lambda _{2},\lambda _{3}$ considering the Bohr atomic model, the wave lengths of first and third spectral lines $(\frac{\lambda _{1}}{\lambda _{3}})$ are related by a factor of approximately $x$ $\times 10^{-1}$ . The value of $x$ , to the nearest integer, is ________.
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Q14 mcq
In thermodynamics, heat and work are :
a.
Path functions
b.
Intensive thermodynamic state variables
c.
Extensive thermodynamic state variables
d.
Point functions
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Q15 mcq
One main scale division of a vernier callipers is $acm$ and $n^{th}$ division of the vernier scale coincide with $(n-1)^{th}$ division of the main scale. The least count of the callipers in $mm$ is :
a.
$\frac{10na}{(n-1)}$
b.
$\frac{10a}{(n-1)}$
c.
$\frac{(n-1)}{10n}$
d.
$\frac{10a}{n}$
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Q16 mcq
The velocity-displacement graph describing the motion of a bicycle is shown in the figure. The acceleration-displacement graph of the bicycle's motion is best described by :
Question 16 image
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Q17 mcq
A conducting bar of length $L$ is free to slide on two parallel conducting rails as shown in the figure Two resistors $R_{1}$ and $R_{2}$ are connected across the ends of the rails. There is a uniform magnetic field $\vec{B}$ pointing into the page. An external agent pulls the bar to the left at a constant speed $v$ . The correct statement about the directions of induced currents $I_{1}$ and $I_{2}$ flowing through $R_{1}$ and $R_{2}$ respectively is :
Question 17 image
a.
Both $I_{1}$ and $I_{2}$ are in anticlockwise direction
b.
Both $I_{1}$ and $I_{2}$ are in clockwise direction
c.
$I_{1}$ is in clockwise direction and $I_{2}$ is in anticlockwise direction
d.
$I_{1}$ is in anticlockwise direction and $I_{2}$ is in clockwise direction
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Q18 mcq
For changing the capacitance of a given paralle plate capacitor, a dielectric material of dielectric constant $K$ is used, which has the same area as the plates of the capacitor. The thickness of the dielectric slab is $\frac{3}{4}d$ , where $d$ is the separation between the plates of parallel plate capacitor. The new capacitance $C'$ in terms of original capacitance $C_{0}$ is given by the following relation :
a.
$C' = \frac{3+K}{4K}C_{0}$
b.
$C' = \frac{4+K}{3}C_{0}$
c.
$C' = \frac{4K}{K+3} C_{0}$
d.
$C' = \frac{4}{3+K}C_{0}$
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Q19 nat
A fringe width of $6\, mm$ was produced for two slits separated by $1\, mm$ apart. The screen is placed $10\,m$ away. The wavelength of light used is $xnm$ . The value of $x$ to the nearest integer is ______.
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Q20 nat
In the logic circuit shown in the figure, if input $A$ and $B$ are $0$ to $1$ respectively, the output at $Y$ would be $x$ . The value of $x$ is _________.
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Q21 nat
A ball of mass $10\, kg$ moving with a velocity $10\,m\,s\sqrt{3}^{-1}$ along $X$ -axis, hits another ball of mass $20\, kg$ which is at rest. After the collision, the first ball comes to rest and the second one disintegrates into two equal pieces. One of the pieces starts moving along $Y$ -axis at a speed of $10\,m\,s^{-1}$ . The second piece starts moving at a speed of $20\,m\,s^{-1}$ at an angle $\theta$ (degree) with respect to the $X$ -axis. The configuration of pieces after the collision is shown in the figure. The value of $\theta$ to the nearest integer is _________.
Question 21 image
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Q22 mcq
A block of mass $m$ slides along a floor while a force of magnitude $F$ is applied to it at an angle $\theta$ as shown in figure. The coefficient of kinetic friction is $\mu _{K}$ . Then, the block's acceleration $a$ is given by : ( $g$ is acceleration due to gravity)
Question 22 image
a.
$-\frac{F}{m} cos\theta - \mu _{K}(g- \frac{F}{m}sin\theta )$
b.
$\frac{F}{m}cos\theta - \mu _{K}(g- \frac{F}{m}sin\theta )$
c.
$\frac{F}{m}cos\theta - \mu _{K}(g+ \frac{F}{m}sin\theta )$
d.
$\frac{F}{m}cos\theta +\mu _{K}(g- \frac{F}{m}sin\theta )$
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Q23 mcq
Time period of a simple pendulum is $T$ inside a lift when the lift is stationary. If the lift moves upwards with an acceleration $\frac{g}{2}$ , the time period of pendulum will be :
a.
$\sqrt{3}T$
b.
$\frac{T}{\sqrt{3}}$
c.
$\sqrt{\frac{3}{2}}T$
d.
$\sqrt{\frac{2}{3}}T$
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Q24 mcq
A plane electromagnetic wave of frequency $500\, MHz$ is traveling in a vacuum along the $y-$ direction. At a particular point in space and time, $\vec{B}= 8. 0 \times 10^{-8}ˆz\,T$ . The value of the electric field at this point is:(speed of light $= 3 \times 10^{8}\, ms^{-1}$ ) $ˆx,ˆy,ˆz$ are unit vectors along $x,y$ and $z$ direction.
a.
$-24ˆx\,V\,m^{-1}$
b.
$2. 6ˆx\,\,V\,m^{-1}$
c.
$24ˆx\,\,V\,m^{-1}$
d.
$-2. 6ˆx\,\,V\,m^{-1}$
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Q25 nat
In the figure given, the electric current flowing through the $5\,k\Omega$ resistor is $xmA$ . The value of $x$ to the nearest integer is ________.
Question 25 image
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Q26 mcq
The pressure acting on a submarine is $3 \times 10^{5}\, Pa$ at a certain depth. If the depth is doubled, the percentage increase in the pressure acting on the submarine would be: (Assume that atmospheric pressure is $1 \times 10^{5}\, Pa$ density of water is $10^{3}\, kg \,m^{-3}, \,g = 10\, ms^{-2}$ )
a.
$\frac{200}{3} %$
b.
$\frac{200}{5} %$
c.
$\frac{5}{200} %$
d.
$\frac{3}{200} %$
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Q27 mcq
A conducting wire of length $l$ , area of crosssection $A$ and electric resistivity $\rho$ is connected between the terminals of a battery. A potential difference $V$ is developed between its ends, causing an electric current. If the length of the wire of the same material is doubled and the area of cross-section is halved, the resultant current would be___
a.
$\frac{1}{4} \frac{V A}{\rho l}$
b.
$\frac{3}{4} \frac{V A}{\rho l}$
c.
$\frac{1}{4} \frac{\rho l}{V A}$
d.
$4\frac{V A}{\rho l}$
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Q28 mcq
A $25\,m$ long antenna is mounted on an antenna tower. The height of the antenna tower is $75\,m$ . The wavelength (in meter) of the signal transmitted by this antenna would be :
a.
$300$
b.
$400$
c.
$200$
d.
$100$
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Q29 nat
The value of power dissipated across the zener diode $(V_{z} = 15\,V)$ connected in the circuit as shown in the figure is $x\times 10^{-1}\,W$ . The value of $x$ to the nearest integer is _______.
Question 29 image
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Q30 mcq
The stopping potential in the context of photoelectric effect depends on the following property of incident electromagnetic radiation:
a.
Phase
b.
Intensity
c.
Amplitude
d.
Frequency
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Q31 mcq
Which of the following is Lindlar catalyst?
a.
Zinc chloride and $HCl$
b.
Cold dilute solution of $KMnO_{4}$
c.
Sodium and Liquid $NH_{3}$
d.
Partially deactivated palladised charcoal
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Q32 mcq
The process that involves the removal of sulphur from the ores is :
a.
Smelting
b.
Roasting
c.
Leaching
d.
Refining
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Q33 nat
Two salts $A_{2}X$ and $MX$ have the same value of solubility product of $4. 0 \times 10^{-12}$ . The ratio of their molar solubilizes i.e. $\frac{S(A_{2}X)}{S(MX)} =$ ________. (Round off to the Nearest Integer).
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Q34 mcq
A group $15$ element, which is a metal and forms a hydride with strongest reducing power among group $15$ hydrides. The element is :
a.
$Sb$
b.
$P$
c.
$As$
d.
$Bi$
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Q35 mcq
Match List-I with List-II : List-I List-II Industrial process Application (a) Haber's process (i) $HNO_{3}$ synthesis (b) Ostwald's process (ii) Aluminium extraction (c) Contact process (iii) $NH_{3}$ synthesis (d) Hall-Heroult process (iv) $H_{2}SO_{4}$ synthesis Choose the correct answer from the options given below:
a.
$(a) -(ii), (b) -(iii), (c) -(iv), (d) -(i)$
b.
$(a) -(iii), (b) -(iv), (c) -(i), (d) -(ii)$
c.
$(a) -(iii), (b) -(i), (c) -(iv), (d) -(ii)$
d.
$(a) -(iv), (b) -(i), (c) -(ii), (d) -(iii)$
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Q36 mcq
Given below are two statement : one is labelled as Assertion A and the other is labelled as Reason R : Assertion A : Size of $Bk^{3+}$ ion is less than $Np^{3+}$ ion. Reason R : The above is a consequence of the lanthanide contraction. In the light of the above statements, choose the correct answer from the options given below :
a.
A is false but R is true
b.
Both A and R are true but R is not the correct explanation of A
c.
A is true but R is false
d.
Both A and R are true and R is the correct explanation of A
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Q37 mcq
Among the following, the aromatic compounds are : Choose the correct answer from the following options :
a.
$(A)$ and $(B)$ only
b.
$(B)$ and $(C)$ only
c.
$(B), (C)$ and $(D)$ only
d.
$(A), (B)$ and $(C)$ only
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Q38 mcq
The type of pollution that gets increased during the daytime and in the presence of $O_{3}$ is :
a.
Reducing smog
b.
Oxidising smog
c.
Global warming
d.
Acid rain
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Q39 mcq
Which of the following reaction DOES NOT involve Hoffmann Bromamide degradation ?
Question 39 image
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Q40 mcq
Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason R : Assertion A : The $H -O -H$ bond angle in water molecule is $104. 5^{\circ}$ . Reason R : The lone pair $-$ lone pair repulsion of electrons is higher than the bond pair $-$ bond pair repulsion.
a.
A is false but R is true
b.
Both A and R are true, but R is not the correct explanation of A
c.
A is true but R is false
d.
Both A and R are true, and R is the correct explanation of A
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Q41 nat
$AB_{2}$ is $10%$ dissociated in water to $A^{2+}$ and $B^{-}$ . The boiling point of $10. 0$ molal aqueous solution of $AB_{2}$ is-- $^{\circ }C$ . (Round off to the Nearest Integer). [Given : Molal elevation constant of water $K_{b} = 0. 5\,K\, kg \, mol^{-1}$ boiling point of pure water $= 100^{\circ}C$ ]
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Q42 nat
$2 MnO^{-}_{4} + bC_{2}O^{2-}_{4} + cH^{+} \rightarrow xMn\rightarrow^{2+} + yCO_{2}+ zH_{2}O$ If the above equation is balanced with integer coefficients, the value of $c$ is _______ . (Round off to the Nearest Integer).
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Q43 nat
Complete combustion of $750\,g$ of an organic compound provides $420\,g$ of $CO_{2}$ and $210\,g$ of $H_{2}O$ . The percentage composition of carbon and hydrogen in organic compound is $15. 3$ and ______ respectively. (Round off to the Nearest Integer)
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Q44 nat
The equivalents of ethylene diamine required to replace the neutral ligands from the coordination sphere of the trans-complex of $CoCl_{3}. 4 NH_{3}$ is _______ . (Round off to the Nearest Integer).
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Q45 nat
A $6. 50$ molal solution of $KOH(aq. )$ has a density of $1. 89\,g\, cm^{-3}$ . The molarity of the solution is $mol \, dm^{-3}$ . (Round off to the Nearest Integer). [Atomic masses: $K : 39. 0\,u; \,O : 16. 0\,u; \,H : 1. 0\,u$ ]
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Q46 nat
For the reaction $A(g) \rightleftharpoons B(g)$ at $495\,K$ , $\Delta _{r}G^{^{\circ}} = -9. 478\, kJ \, mol^{-1}$ If we start the reaction in a closed container at $495\,K$ with $22$ millimoles of $A$ , the amount of $B$ is the equilibrium mixture is ________ millimoles. (Round off to the Nearest Integer). $[R = 8. 314\,J\, mol^{-1} \,K^{-1}; \ell n10 = 2. 303]$
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Q47 mcq
Given below are two statements: Statement I : $H_{2}O_{2}$ can act as both oxidising and reducing agent in basic medium. Statement II : In the hydrogen economy, the energy is transmitted in the form of dihydrogen. In the light of the above statements, choose the correct answer from the options given below:
a.
Both statement I and statement II are false
b.
Both statement I and statement II are true
c.
Statement I is true but statement II is false
d.
Statement I is false but statement II is true
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Q48 mcq
Match List-I with List-II List-I List-II Name of oxo acid Oxidation state of ' $P$ (a) Hypophosphorous acid (i) $+5$ (b) Orthophosphoric acid (ii) $+4$ (c) Hypophosphoric acid (iii) $+3$ (d) Orthophosphorous acid (iv) $+2$ (v) $+1$ Choose the correct answer from the options given below :
a.
$(a) -(v), \,(b) -(i), \,(c) -(ii), \,(d) -(iii)$
b.
$(a) -(iv), \,(b) -(i), \,(c) -(ii), \,(d) -(iii)$
c.
$(a) -(iv), \,(b) -(v), \,(c) -(ii), \,(d) -(iii)$
d.
$(a) -(v), \,(b) -(iv), \,(c) -(ii), \,(d) -(iii)$
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Q49 mcq
Given below are two statements: Statement I : Both $CaCl_{2}. 6H_{2}O$ and $MgCl_{2}. 8H_{2}O$ undergo dehydration on heating. Statement II : $BeO$ is amphoteric, whereas the oxides of other elements in the same group are acidic. In the light of the above statements, choose the correct answer from the options given below:
a.
Statement I is false but statement II is true
b.
Both statement I and statement II are false
c.
Both statement I and statement II are true
d.
Statement I is true but statement II is false
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Q50 nat
A certain element crystallises in a bcc lattice of unit cell edge length 27 $A^{o}$ . If the same element under the same conditions crystallises in the $fcc$ lattice, the edge length of the unit cell in $A^{o}$ will be __________. (Round off to the Nearest Integer). [Assume each lattice point has a single atom] [Assume $\sqrt{3}= 1. 73, \, = 1. 41\sqrt{2}$ ]
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Q51 mcq
The product " $A$ " and " $B$ " formed in above reactions are
Question 51 image
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Q52 mcq
Given below are two statements : Statement I : The $E^{\circ}$ value of $Ce^{4+} / Ce^{3+}$ is $+1. 74\,V$ Statement II : Ce is more stable in $Ce^{4+}$ state than $Ce^{3+}$ state. In the light of the above statements, choose the most appropriate answer from the options given below:
a.
Both statement I and statement II are correct
b.
Statement I is incorrect but statement II is correct
c.
Both statement I and statement II are incorrect
d.
Statement I is correct but statement II is incorrect
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Q53 mcq
Assertion A : Enol form of acetone $[CH_{3}COCH_{3}]$ exists in $< 0. 1%$ quantity. However, the enol form of acetyl acetone $[CH_{3}COCH_{2}OCCH_{3}]$ exists in approximately $15%$ quantity. Reason R : enol form of acetyl acetone is stabilized by intramolecular hydrogen bonding, which is not possible in enol form of acetone. Choose the correct statement:
a.
A is false but R is true
b.
Both A and R are true and R is the correct explanation of A
c.
Both A and R are true but R is not the correct explanation of A
d.
A is true but R is false
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Q54 nat
When light of wavelength $248\, nm$ falls on a metal of threshold energy $3. 0\, eV$ , the de-Broglie wavelength of emitted electrons is ________ $A^{o}$ . (Round off to the Nearest Integer). [Use : $\sqrt{3}= 1. 73, \,h = 6. 63 \times 10^{-34}\, Js; \,m_{e} = 9. 1 \times 10^{-31}\, kg; \,c = 3. 0 \times 10^{8}\, ms^{-1}; \,1\,eV = 1. 6 \times 10^{-19}\,J]$
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Q55 nat
The decomposition of formic acid on gold surface follows first order kinetics. If the rate constant at $300\,K$ is $1. 0 \times 10^{-3}\,s^{-1}$ and the activation energy $E_{a} = 11. 488\, kJ \, mol^{-1}$ , the rate constant at $200\,K$ is _________ $\times 10^{-5}\,s^{-1}$ . (Round of to the Nearest Integer). (Given $R = 8. 314\,J\, mol^{-1}\,K^{-1}$ )
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Q56 mcq
The functions of antihistamine are :
a.
Antiallergic and Analgesic
b.
Antacid and Antiallergic
c.
Analgesic and antacid
d.
Antiallergic and antidepressant
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Q57 mcq
Which among the following pairs of Vitamins is stored in our body relatively for longer duration?
a.
Thiamine and Vitamin $A$
b.
Vitamin $A$ and $D$
c.
Thiamine and Ascorbic acid
d.
Ascorbic acid and Vitamin $D$
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Q58 mcq
In chromatography technique, the purification of a compound is independent of:
a.
Mobility or flow of solvent system
b.
Solubility of the compound
c.
Length of the column or $TLC$ Plate
d.
Physical state of the pure compound
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Q59 mcq
In the above chemical reaction, intermediate " $X$ " and reagent/condition " $A$ " are :
Question 59 image
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Q60 mcq
The product " $P$ " in the above reaction is :
Question 60 image
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Q61 mcq
The number of elements in the set ${x\in R: (|x| -3)|x+ 4| = 6}$ is equal to
a.
$3$
b.
$2$
c.
$4$
d.
$1$
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Q62 mcq
$i -i x 8$ Let $A=[ ],i= \sqrt{-1}$ . Then, the system of linear equations $A^{8}[ ]=[ ]$ has : $-i i y 64$
a.
A unique solution
b.
Infinitely many solutions
c.
No solution
d.
Exactly two solutions
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Q63 mcq
If $n$ is the number of irrational terms in the expansion of $(3^{1/4} + 5^{1/8})^{60}$ , then $(n-1)$ is divisible by :
a.
$26$
b.
$30$
c.
$8$
d.
$7$
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Q64 mcq
If $y=y(x)$ is the solution of the differential equation, $\frac{dy}{dx} + 2ytanx= sinx,y(\frac{\pi}{3})= 0$ , then the maximum value of the function $y(x)$ over $R$ is equal to :
a.
$8$
b.
$\frac{1}{2}$
c.
$-\frac{15}{4}$
d.
$\frac{1}{8}$
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Q65 mcq
Let a complex number $z, \,|z| \neq 1$ , satisfy $log\frac{1}{\sqrt{2}} (\frac{|z|+11}{(|z|-1)^{2}})\leq 2$ . Then, the largest value of $|z|$ is equal to _________.
a.
$8$
b.
$7$
c.
$6$
d.
$5$
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Q66 nat
Let $f : (0, 2) R$ be defined as $f(x) = log_{2}(1 + tan(\frac{\pi x}{4}))$ . Then, $_{n}lim_{\rightarrow \infty \rightarrow } \frac{2}{n}(\vec{f}(\frac{1}{n})+f( \frac{2}{n})+ … . +f(1))$ is equal to ________.
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Q67 mcq
Let a vector $\alpha$ $ˆi +$ $\beta$ $ˆj$ be obtained by rotating the vector $\sqrt{3}ˆi +ˆj$ by an angle $45^{\circ}$ about the origin in counterclockwise direction in the first quadrant. Then the area (in sq. units) of triangle having vertices $(\alpha ,\beta ), (0,\beta )$ and $(0, 0)$ is equal to
a.
$\frac{1}{2}$
b.
$1$
c.
$\frac{1}{\sqrt{2}}$
d.
$2\sqrt{2}$
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Q68 nat
Let the curve $y=y(x)$ be the solution of the differential equation, $\frac{dy}{dx} = 2(x+ 1)$ . If the numerical value of area bounded by the curve $y=y(x)$ and $x$ -axis is $\frac{4\sqrt{8}}{3}$ , then the value of $y(1)$ is equal to ________.
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Q69 mcq
Let $S_{k} =\sum ^{k}_{r=1} tan^{-1}(\frac{6^{r}}{2^{2}^{r}^{+1}+3^{2}^{r}^{+1}}),$ then $_{k}lim_{\rightarrow \infty \rightarrow } S_{k}$ is equal to :
a.
$tan^{-1}(\frac{3}{2})$
b.
$\frac{\pi}{2}$
c.
$cot^{-1}(\frac{3}{2} )$
d.
$tan^{-1}(3)$
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Q70 mcq
If for $a> 0$ , the feet of perpendiculars from the points $A(a, -2a, 3)$ and $B(0, 4, 5)$ on the plane $lx+my+nz= 0$ are points $C(0, -a, -1)$ and $D$ respectively, then the length of line segment $CD$ is equal to :
a.
$\sqrt{31}$
b.
$\sqrt{41}$
c.
$\sqrt{55}$
d.
$\sqrt{66}$
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Q71 mcq
A pack of cards has one card missing. Two cards are drawn randomly and are found to be spades. The probability that the missing card is not a spade, is :
a.
$\frac{3}{4}$
b.
$\frac{52}{867}$
c.
$\frac{39}{50}$
d.
$\frac{22}{425}$
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Q72 mcq
Let the position vectors of two points $P$ and $Q$ be $3ˆi -ˆj + 2ˆk$ and $ˆi + 2ˆj -4ˆk$ , respectively. Let $R$ and $S$ be two points such that the direction ratios of lines $PR$ and $QS$ are $(4, -1, 2)$ and $(-2, 1, -2)$ , respectively. Let $---$ lines $PR$ and $QS$ intersect at $T$ . If the vector $T\vec{A}$ is perpendicular to both $P\vec{R}$ and $Q\vec{S}$ and the length of vector $-$ $T\vec{A}$ is $\sqrt{5}$ units, then the modulus of a position vector of $A$ is :
a.
$\sqrt{482}$
b.
$\sqrt{171}$
c.
$\sqrt{5}$
d.
$\sqrt{227}$
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Q73 nat
$||$ Let $ABCD$ be a square of side of unit length. Let a circle $C_{1}$ centered at $A$ with unit radius is drawn. Another circle $C_{2}$ which touches $C_{1}$ and the lines $AD$ and $AB$ are tangent to it, is also drawn. Let a tangent line from the point $C$ to the circle $C_{2}$ meet the side $AB$ at $E$ . If the length of $EB$ is $\alpha + \sqrt{3}\beta$ , where $\alpha ,\beta$ are integers, then $\alpha +\beta$ is equal to ________.
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Q74 mcq
Let $P$ be a plane $lx+my+nz= 0$ containing the line, $\frac{1-x}{1} = \frac{y+4}{2} = \frac{z+2}{3}$ . If plane $P$ divides the line segment $AB$ joining points $A(-3, -6, 1)$ and $B(2, 4, -3)$ in ratio $k: 1$ then the value of $k$ is equal to :
a.
$1. 5$
b.
$3$
c.
$2$
d.
$4$
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Q75 nat
If $_{x}lim_{0} \frac{ae^{x}-bcosx+ce^{-}^{x}}{xsinx} = 2$ , then $a+b+c$ is equal to ________.
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Q76 nat
The total number of $3 \times 3$ matrices $A$ having enteries from the set $(0, 1, 2, 3)$ such that the sum of all the diagonal entries of $AA^{T}$ is $9$ , is equal to
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Q77 nat
Let $f :R\rightarrow \rightarrow R$ be a continuous function such that $f(x) +f(x+ 1) = 2$ for all $x\in R$ . If $I_{1} =\int _{0}^{8} f(x)dx$ and $I_{2} =\int _{-1}^{3} f(x)dx$ , then the value of $I_{1}+ 2I_{2}$ is equal to ________.
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Q78 mcq
Let $[x]$ denote greatest integer less than or equal to $x$ . If for $n\in N,(1 - x+x^{3})^{n} =\sum ^{3}_{j=0}^{n} a_{j}x^{j}$ , then $\sum _{j}^{[}_{=0}\frac{3n}{2}^{]} a_{2j}+ 4\sum ^{[}_{j=0}\frac{3n-1}{2}^{]} a_{2j+1}$ is equal to :
a.
$2$
b.
$2^{n-1}$
c.
$1$
d.
$n$
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Q79 nat
$-^{Let}z^{and}w^{be two complex numbers such that}w=zz-2z+ 2, \frac{z+i}{z-3i} = 1^{and}Re (w)^{has minimum value.}$ Then, the minimum value of $n\in N$ for which $w^{n}$ is real, is equal to _______.
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Q80 mcq
Which of the following Boolean expression is a tautology ?
a.
$(p\wedge q) \vee (p\vee q)$
b.
$(p\wedge q) \vee (p\rightarrow \rightarrow q)$
c.
$(p\wedge q) \wedge (p\rightarrow \rightarrow q)$
d.
$(p\wedge q) \rightarrow (\rightarrow p\rightarrow \rightarrow q)$
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Q81 mcq
The range of $a\in R$ for which the function $f(x) = (4a-3)(x+ log_{e}5) + 2(a-7) cot( \frac{x}{2} )sin^{2}(\frac{x}{2}),x\neq 2n\pi ,n\in N$ , has critical points, is :
a.
$(-3, 1)$
b.
$[-\frac{4}{3} , 2]$
c.
$[1, \infty )$
d.
$(-\infty , -1]$
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Q82 mcq
The locus of the midpoints of the chord of the circle, $x^{2} +y^{2} = 25$ which is tangent to the hyperbola, $\frac{x^{2}}{9} - \frac{y^{2}}{16} = 1$ is :
a.
$(x^{2} +y^{2})^{2} -16x^{2} + 9y^{2} = 0$ $^{2}-9$
b.
$(x^{2} +y^{2})^{2} -9x^{2} + 144y^{2} = 0$ $^{2}-9$
c.
$(x^{2} +y^{2}) x^{2}-16y^{2} = 0$
d.
$(x^{2} +y^{2}) x^{2}+ 16y^{2} = 0$
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Q83 mcq
If the three normals drawn to the parabola, $y^{2} = 2x$ pass through the point $(a, 0), \,a\neq 0$ , then $a$ must be greater than :
a.
$\frac{1}{2}$
b.
$-\frac{1}{2}$
c.
$-1$
d.
$1$
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Q84 nat
Consider an arithmetic series and a geometric series having four initial terms from the set ${11, 8, 21, 16, 26, 32, 4}$ . If the last terms of these series are the maximum possible four digit numbers, then the number of common terms in these two series is equal to _______.
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Q85 mcq
Consider three observations $a,b$ and $c$ such that $b=a+c$ . If the standard deviation of $a+ 2,c+ 2$ is $d$ , then which of the following is true?
a.
$b^{2} = 3(a^{2} +c^{2})+ 9d^{2}$
b.
$b^{2} =a^{2} +c^{2} + 3d^{2}$
c.
$b^{2} = 3(a^{2} +c^{2} +d^{2})$
d.
$b^{2} = 3(a^{2} +c^{2})-9d^{2}$
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Q86 nat
$-30 20 56 2 7 \omega ^{2}$ $[ ] [ ]$ Let $\vec{P} = 90 140 112$ and $A= -1 -\omega 1$ where $\omega = \frac{-1+i\sqrt{3}}{2}$ , and $I_{3}$ be the identity matrix $[ ] [ ]$ $120 60 14 0 -\omega -\omega + 1$ of order $3$ . If the determinant of the matrix $(P^{-1}AP - I_{3})^{2}$ is $\alpha \omega ^{2}$ , then the value of $\alpha$ is equal to _________.
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Q87 mcq
The number of roots of the equation, $(81)^{sin^{2}x} + (81)^{cos^{2}x} = 30$ in the interval $[0,\pi ]$ is equal to :
a.
$3$
b.
$4$
c.
$8$
d.
$2$
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Q88 mcq
Let the functions $f :R\rightarrow \rightarrow R$ and $g:R R$ be defined as : $x+ 2, x< 0 x^{3}, x< 1$ $f(x) ={$ and $g(x) ={$ $x^{2}, x\geq 0 3\vec{x}-2, x\geq 1$ Then, the number of points in $R$ where $(fog)(x)$ is NOT differentiable is equal to :
a.
$3$
b.
$1$
c.
$0$
d.
$2$
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Q89 mcq
If for $x\in (0, \frac{\pi}{2}), log_{10} sinx+ log_{10} cosx= -1$ and $log_{10}(sinx+ cosx) = \frac{1}{2}(log_{10} n-1),n> 0$ , then the value of $n$ is equal to :
a.
$20$
b.
$12$
c.
$9$
d.
$16$
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Q90 nat
If the normal to the curve $y(x) =\int _{0}^{x}(2t^{2}-15t+ 10)dt$ at a point $(a,b)$ is parallel to the line $x+ 3y= -5,a> 1$ , then the value of $|a+ 6b|$ is equal to ________.
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