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JEE Main 2021 (26 Feb Shift 2)

2021 · 90 questions · First 10 Solutions Free
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Q1 mcq
The incident ray, reflected ray and the outward drawn normal are denoted by the unitvectors $\vec{a}, \vec{b}$ and $\vec{c}$ respectively. Then choose the correct relation for these vectors.
a.
$\vec{b}= \vec{a}+ 2\vec{c}$
b.
$\vec{b}= 2\vec{a}+ \vec{c}$
c.
$\vec{b}= \vec{a}-2(\vec{a}\cdot \vec{c})\vec{c}$ Correct Answer
d.
$\vec{b}= \vec{a}- \vec{c}$

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Q2 nat
Two stream of photons, possessing energies equal to twice and ten times the work function of metal are incident on the metal surface successively. The value of ratio of maximum velocities of the photoelectrons emitted in the two respective cases is $x: 3$ The value of $x$ is
✓ Accepted Answer: 1

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Q3 nat
A particle executes S.H.M. with amplitude $A$ and time period $T$ . The displacement of the particle when its speed is half of maximum speed is $\frac{\sqrt{x}A}{2}.$ The value of $x$ is
✓ Accepted Answer: 3

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Q4 mcq
The length of metallic wire is $l_{1}$ when tension in it is $T_{1}$ . It is $l_{2}$ when the tension is $T_{2}$ . The original length of the wire will be :
a.
$\frac{T_{2}l_{1}+T_{1}l_{2}}{T_{1}+T_{2}}$
b.
$\frac{l_{1}+l_{2}}{2}$
c.
$\frac{Tl-Tl}{T_{2}-T_{1}}^{2}^{1}^{1}^{2}$ Correct Answer
d.
$\frac{Tl-Tl}{\,T_{2}-T_{1}}^{1}^{1}^{2}^{2}$

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Q5 mcq
Given below are two statements : one is labeled as Assertion $A$ and the other is labeled as Reason $R$ . Assertion $A$ : For a simple microscope, the angular size of the object equals the angular size of the image. Reason $R$ : Magnification is achieved as the small object can be kept much closer to the eye than $25\, cm$ and hence it subtends a large angle. In the light of the above statements, choose the most appropriate 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 $A$ Correct Answer

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Q6 mcq
A cord is wound round the circumference of wheel of radius $r$ , The axis of the wheel is horizontal and the moment of inertia about it is $I$ . A weight $mg$ is attached to the cord at the end. The weight falls from rest. After falling through a distance $h,$ the square of angular velocity of wheel will be
a.
$\frac{2mgh}{I+mr^{2}}$ Correct Answer
b.
$\frac{2mgh}{I+2mr^{2}}$
c.
$2gh$
d.
$\frac{2gh}{I+mr^{2}}$

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Q7 nat
If the highest frequency modulating a carrier is $5\, kHz$ , then the number of $AM$ broadcast stations accommodated in a $90\, kHz$ bandwidth are
✓ Accepted Answer: 9

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Q8 nat
A point source of light $S$ , placed at a distance $60\, cm$ infront of the centre of a plane mirror of width $50\, cm$ , hangs vertically on a wall. A man walks infront of the mirror along a line parallel to the mirror at a distance $1. 2\,m$ from it (see in the figure). The distance between the extreme points where he can see the image of the light source in the mirror is__ $cm$
Question 8 image
✓ Accepted Answer: 150

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Q9 nat
In the reported figure of earth, the value of acceleration due to gravity is same at point $A$ and $C$ but it is smaller than that of its value at point $B$ (surface of the earth). The value of $OA:AB$ will be $x: 5$ . The value of $x$ is
Question 9 image
✓ Accepted Answer: 4

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Q10 mcq
Find the peak current and resonant frequency of the following circuit (as shown in figure).
Question 10 image
a.
$2\,A$ and $50\, Hz$
b.
$0. 2\,A$ and $100\, Hz$
c.
$2\,A$ and $100\, Hz$
d.
$0. 2\,A$ and $50\, Hz$ Correct Answer

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Q11 mcq
A radioactive sample is undergoing $\alpha$ decay, At any time $t_{1},$ its activity is $A$ and another time $t_{2},$ the activity is $\frac{A}{5}$ . What is the average life time for the sample ?
a.
$\frac{ln 5}{t_{2}-t_{1}}$
b.
$\frac{ln(t_{2}+t_{1})}{2}$
c.
$\frac{t_{2}-t_{1}}{ln 5}$
d.
$\frac{t_{1}-t_{2}}{ln 5}$
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Q12 mcq
An aeroplane, with its wings spread $10\,m,$ is flying at a speed of $180\, km \,h^{-1}$ in a horizontal direction. The total intensity of earth's field at that part is $2. 5 \times 10^{-4}\, Wb \,m^{-2}$ and the angle of dip is $60^{\circ}.$ The emf induced between the tips of the plane wings will be
a.
$108. 25\, mV$
b.
$54. 125\, mV$
c.
$88. 37\, mV$
d.
$62. 50\, mV$
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Q13 nat
The zener diode has a $V_{z} = 30\,V$ . The current passing through the diode for the following circuit is___ $mA.$
Question 13 image
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Q14 mcq
Two masses $A$ and $B$ , each of mass $M$ are fixed together by a massless spring, A force acts on the mass $B$ as shown in figure. If the mass $A$ starts moving away from mass $B$ with acceleration $a$ , then the acceleration of mass $B$ will be :
Question 14 image
a.
$\frac{MF}{F+Ma}$
b.
$\frac{F+Ma}{M}$
c.
$\frac{Ma-F}{M}$
d.
$\frac{F-Ma}{M}$
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Q15 mcq
The trajectory of a projectile in a vertical plane is $y=\alpha x- \beta x^{2},$ where $\alpha$ and $\beta$ are constants and $x\,&\,y$ are respectively the horizontal and vertical distances of the projectile from the point of projection. The angle of projection $\theta$ and the maximum height attained $H$ are respectively given by
a.
$tan^{-1} \alpha , \frac{4\alpha ^{2}}{\beta}$
b.
$tan^{-1}(\frac{\beta}{\alpha}), \frac{\alpha ^{2}}{\beta}$
c.
$tan^{-1} \beta , \frac{\alpha ^{2}}{2\beta}$
d.
$tan^{-1} \alpha , \frac{\alpha ^{2}}{4\beta}$
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Q16 mcq
If $C$ and $V$ represent capacity and voltage respectively then what are the dimensions of $\lambda$ where $C/V =\lambda$ ?
a.
$[M^{-2}\,L^{-4}\,I^{3}\,T^{7}]$
b.
$[M^{-2}\,L^{-3}I^{2}\,T^{6}]$
c.
$[M^{-1}\,L^{-3}I^{-2}\,T^{-7}]$
d.
$[M^{-3}\,L^{-4}I^{3}\,T^{7}]$
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Q17 mcq
A tuning fork $A$ of unknown frequency produces $5\, beats \,s^{-1}$ with a fork of known frequency $340\, Hz$ . When fork $A$ is filed, the beat frequency decreases to $2\, beats \,s^{-1}$ . What is the frequency of fork $A$ ?
a.
$335\, Hz$
b.
$338\, Hz$
c.
$345\, Hz$
d.
$342\, Hz$
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Q18 mcq
Draw the output signal $Y$ in the given combination of gates.
Question 18 image
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Q19 nat
The volume $V$ of a given mass of monoatomic gas changes with temperature $T$ according to the relation $V =KT \frac{2}{3}$ . The workdone when temperature changes by $90\,K$ will be $xR$ . The value of $x$ is [ $R$ universal gas constant ]
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Q20 mcq
A wire of $1\,\Omega$ has a length of $1\,m$ . It is stretched till its length increases by $25%$ . The percentage change in resistance to the nearest integer is :
a.
$12. 5%$
b.
$76%$
c.
$25%$
d.
$56%$
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Q21 mcq
The recoil speed of a hydrogen atom after it emits a photon in going from $n= 5$ state to $n= 5$ state will be
a.
$4. 17\,m\,s^{-1}$
b.
$2. 19\,m\,s^{-1}$
c.
$4. 34\,m\,s^{-1}$
d.
$3. 25\,m\,s^{-1}$
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Q22 mcq
A scooter accelerates from rest for time $t_{1}$ at constant rate $a_{1}$ and then retards at constant rate $a_{2}$ for time $t_{2}$ and comes to rest. The correct value of $\frac{t_{1}}{t_{2}}$ will be :
a.
$\frac{a}{a_{1}}^{2}$
b.
$\frac{a}{a_{2}}^{1}$
c.
$\frac{a_{1}+a_{2}}{a_{1}}$
d.
$\frac{a_{1}+a_{2}}{a_{2}}$
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Q23 mcq
Given below are two statements Statement $I$ : An electric dipole is placed at the centre of a hollow sphere. The flux of electric field through the sphere is zero, but the electric field is not zero anywhere in the sphere. Statement $II$ : If $R$ is the radius of a solid metallic sphere and $Q$ be the total charge on it. The electric field at any point on the spherical surface of radius $r(<R)$ is zero but the electric flux passing through this closed spherical surface of radius $r$ is not In the light of the above statements, choose the correct answer from the options given below:
a.
Both Statement $I$ and Statement $II$ are true
b.
Statement $I$ is false but Statement $II$ is true
c.
Statement $I$ is true but Statement $II$ is false
d.
Both Statement $I$ and Statement $II$ are false
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Q24 mcq
A particle executes S.H.M., the graph of velocity as a function of displacement is :
a.
a circle
b.
a helix
c.
a parabola
d.
an ellipse
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Q25 nat
Time period of a simple pendulum is $T$ . The time taken to complete $\frac{5}{8}$ oscillations starting from mean position is $\frac{\alpha}{12}T$ . The value of $\alpha$ is $______$ .
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Q26 mcq
An inclined plane making an angle of $30^{\circ}$ with the horizontal is placed in a uniform horizontal electric field $200\frac{N}{C}$ as shown in the figure. A body of mass $1\, kg$ and charge $5\, mC$ is allowed to slide down from rest at a height of $1\,m$ . If the coefficient of friction is $0. 2,$ find the time taken by the body to reach the bottom. $[g= 9. 8\,m\,s^{-2}; \, sin 30^{\circ}= \frac{1}{2} ; \, cos 30^{\circ}= \frac{\sqrt{3}}{2}]$
Question 26 image
a.
$0. 92\,s$
b.
$1. 3\,s$
c.
$0. 46\,s$
d.
$2. 3\,s$
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Q27 mcq
Given below are two statements: Statement $I$ : A second's pendulum has a time period of $1$ second. Statement $II$ : It takes precisely one second to move between the two extreme positions. 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 true
c.
Both Statement $I$ and Statement $II$ are False
d.
Statement $I$ is true but Statement $II$ is false
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Q28 nat
$1$ mole of rigid diatomic gas performs a work of $\frac{Q}{5}$ when heat $Q$ is supplied to it. The molar heat capacity of the gas during this transformation is $\frac{xR}{8}.$ The value of $x$ is [ $R$ universal gas constant]
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Q29 nat
$27$ similar drops of mercury are maintained at $10\,V$ each. All these spherical drops combine into a single big drop. The potential energy of the bigger drop is ___________ times that of a smaller drop.
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Q30 mcq
The internal energy $(U)$ , pressure $(P)$ and volume $(V)$ of an ideal gas are related as $U\, = 3PV + 4.$ The gas is
a.
either monoatomic or diatomic
b.
polyatomic only
c.
monoatomic only
d.
diatomic only
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Q31 nat
A ball weighing $10\,g$ is moving with a velocity of $90\,m\,s^{-1}.$ If the uncertainty in its velocity is $5%$ , then the uncertainty in its position is _ $\times 10^{-33}\,m.$ (Rounded off to the nearest integer) [Given: $h = 6. 63 \times 10^{-34}\, Js$ ]
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Q32 mcq
Match List- $I$ with List- $II$ List- $I$ List- $II$ (a) Sodium Carbonate (i) Deacon (b) Titanium (ii) Castner-Kellner (c) Chlorine (iii) van-Arkel (d) Sodium hydroxide (iv) Solvay Choose the correct answer from the options given below:
a.
$(a) \rightarrow (i), \,(b) \rightarrow (iii), \,(c) \rightarrow (iv), \,(d) \rightarrow (ii)\rightarrow \rightarrow \rightarrow \rightarrow$
b.
$(a) \rightarrow (iii), \,(b) \rightarrow (ii), \,(c) \rightarrow (i), \,(d) \rightarrow (iv)\rightarrow \rightarrow \rightarrow \rightarrow$
c.
$(a) \rightarrow (iv), \,(b) \rightarrow (i), \,(c) \rightarrow (ii), \,(d) \rightarrow (iii)\rightarrow \rightarrow \rightarrow \rightarrow$
d.
$(a) \rightarrow (iv), \,(b) \rightarrow (iii), \,(c) \rightarrow (i), \,(d) \rightarrow (ii)\rightarrow \rightarrow \rightarrow \rightarrow$
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Q33 mcq
The correct order of electron gain enthalpy is:
a.
$S > O > Se > Te$
b.
$O > S > Se > Te$
c.
$S > Se > Te > O$
d.
$Te > Se > S > O$
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Q34 mcq
Which of the following forms of hydrogen emits low energy $\beta$ $^{-}$ particles?
a.
Deuterium $^{2}_{1}H$
b.
Proton $H^{+}$
c.
Tritium $^{3}_{1}H$
d.
Protium $^{1}_{1}H$
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Q35 mcq
Match List- $I$ with List- $II$ . List- $I$ List- $II$ (Molecule) (Bond order) (a) $Ne_{2}$ (i) $1$ (b) $N_{2}$ (ii) $2$ (c) $F_{2}$ (iii) $0$ (d) $O_{2}$ (iv) $3$ Choose the correct answer from the options given below:
a.
$(a) \rightarrow (ii), \,(b) \rightarrow (i), \,(c) \rightarrow (iv), \,(d) \rightarrow (iii)\rightarrow \rightarrow \rightarrow \rightarrow$
b.
$(a) \rightarrow (iii), \,(b) \rightarrow (iv), \,(c) \rightarrow (i), \,(d) \rightarrow (ii)\rightarrow \rightarrow \rightarrow \rightarrow$
c.
$(a) \rightarrow (i), \,(b) \rightarrow (ii), \,(c) \rightarrow (iii), \,(d) \rightarrow (iv)\rightarrow \rightarrow \rightarrow \rightarrow$
d.
$(a) \rightarrow (iv), \,(b) \rightarrow (iii), \,(c) \rightarrow (ii), \,(d) \rightarrow (i)\rightarrow \rightarrow \rightarrow \rightarrow$
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Q36 nat
In mildly alkaline medium, thiosulphate ion is oxidized by $MnO^{-}_{4}$ to $''A''$ . The oxidation state of sulphur in $''A''$ is_
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Q37 mcq
Calgon is used for water treatment. Which of the following statement is NOT true about Calgon?
a.
It is polymeric compound and is water soluble.
b.
Calgon contains the $2^{nd}$ most abundant element by weight in the Earth's crust.
c.
It is also known as Graham's salt.
d.
It doesnot remove $Ca^{2+}$ ion by precipitation.
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Q38 nat
The average $S -F$ bond energy in $kJ \, mol^{-1}$ of $SF_{6}$ is _. (Rounded off to the nearest integer) [Given : The values of standard enthalpy of formation of $SF_{6}(g), \,S(g)$ and $F(g)$ are $-1100, \,275$ and $80\, kJ \, mol^{-1}$ respectively.]
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Q39 nat
The $NaNO_{3}$ weighed out to make $50\, mL$ of an aqueous solution containing $70. 0\, mg \, Na^{+}$ per $mL$ is_ $g$ . (Rounded off to the nearest integer) [Given : Atomic weight in $gmol^{-1} -Na \, : \,23; \,N\, : \,14; \,O\, : \,16$ ]
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Q40 nat
$|\parallel |$ The number of stereo isomers possible for $[Co (ox)_{2}(Br)(NH_{3})]^{2-}$ is __________. [ $ox =$ oxalate]
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Q41 mcq
The nature of charge on resulting colloidal particles when $FeCl_{3}$ is added to excess of hot water is:
a.
positive
b.
sometimes positive and sometimes negative
c.
neutral
d.
negative
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Q42 mcq
Ceric ammonium nitrate and $CHCl_{3}/ alc$ . $KOH$ are used for the identification of functional groups present in _ and _ respectively.
a.
amine, phenol
b.
alcohol, amine
c.
amine, alcohol
d.
alcohol, phenol
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Q43 nat
$Emf$ of the following cell at $298\,K$ in $V$ is $x \times 10^{-2}$ $Zn Zn^{2+}(0. 1M) Ag^{+}(0. 01M) Ag$ The value of $x$ is ________________ (Rounded off to the nearest integer) $[Given : \,E^{\theta }_{Zn^{2+}/ Zn} = -0. 76\,V; \,E^{\theta }_{Ag^{+}/ Ag} = +0. 80\,V; \,\,\frac{2.303 RT}{F} = 0. 059]$
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Q44 mcq
Match List- $I$ with List- $II$ . List- $I$ List- $II$ (a) Siderite (i) $Cu$ (b) Calamine (ii) $Ca$ (c) Malachite (iii) $Fe$ (d) Cryolite (iv) $Al$ (v) $Zn$ Choose the correct answer from the options given below:
a.
$(a) \rightarrow (iii), \,(b) \rightarrow (i), \,(c) \rightarrow (v), \,(d) \rightarrow (ii)\rightarrow \rightarrow \rightarrow \rightarrow$
b.
$(a) \rightarrow (i), \,(b) \rightarrow (ii), \,(c) \rightarrow (v), \,(d) \rightarrow (iii)\rightarrow \rightarrow \rightarrow \rightarrow$
c.
$(a) \rightarrow (iii), \,(b) \rightarrow (v), \,(c) \rightarrow (i), \,(d) \rightarrow (iv)\rightarrow \rightarrow \rightarrow \rightarrow$
d.
$(a) \rightarrow (i), \,(b) \rightarrow (ii), \,(c) \rightarrow (iii), \,(d) \rightarrow (iv)\rightarrow \rightarrow \rightarrow \rightarrow$
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Q45 nat
When $12. 2\,g$ of benzoic acid is dissolved in $100\,g$ of water, the freezing point of solution was found to be $-0. 93\,^{\circ}C(K_{f}(H_{2}O) = 1. 86\,K\, kg \, mol^{-1})$ . The number $(n)$ of benzoic acid molecules associated (assuming $100%$ association) is _.
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Q46 mcq
Match List- $I$ with List- $II$ . List- $I$ List- $II$ (a) Sucrose (i) $\beta$ $-D-$ Galactose and $\beta$ $-D-$ Glucose (b) Lactose (ii) $\alpha$ $-D-$ Glucose and $\beta$ $-D-$ Fructose (c) Maltose (iii) $\alpha$ $-D-$ Glucose and $\alpha$ $-D-$ Glucose Choose the correct answer from the options given below:
a.
$(a) \rightarrow (iii), \,(b) \rightarrow (ii), \,(c) \rightarrow (i)\rightarrow \rightarrow \rightarrow$
b.
$(a) \rightarrow (iii), \,(b) \rightarrow (i), \,(c) \rightarrow (ii)\rightarrow \rightarrow \rightarrow$
c.
$(a) \rightarrow (ii), \,(b) \rightarrow (i), \,(c) \rightarrow (iii)\rightarrow \rightarrow \rightarrow$
d.
$(a) \rightarrow (i), \,(b) \rightarrow (iii), \,(c) \rightarrow (ii)\rightarrow \rightarrow \rightarrow$
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Q47 mcq
Which pair of oxides is acidic in nature?
a.
$B_{2}O_{3}, \, CaO$
b.
$N_{2}O, \, BaO$
c.
$CaO, \, SiO_{2}$
d.
$B_{2}O_{3}, \, SiO_{2}$
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Q48 mcq
$2, \,4 -DNP$ test can be used to identify :
a.
aldehyde
b.
amine
c.
halogens
d.
ether
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Q49 nat
The number of octahedral voids per lattice site in a lattice is_. (Rounded off to the nearest integer)
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Q50 mcq
Given below are two statements: one is labelled as Assertion $A$ and the other is labelled as Reason $R$ . Assertion $A :$ In $TlI_{3},$ isomorphous to $CsI_{3}$ , the metal is present in $+1$ oxidation state. Reason $R : Tl$ metal has fourteen $f$ electrons in its electronic configuration. In the light of the above statements, choose the most appropriate answer from the options given below:
a.
$A$ is correct but $R$ is not correct
b.
Both $A$ and $R$ are correct and $R$ is the correct explanation of $A$
c.
$A$ is not correct but $R$ is correct
d.
Both $A$ and $R$ are correct but $R$ is $NOT$ the correct explanation of $A$
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Q51 mcq
Match List- $I$ with List- $II$ . List- $I$ List- $II$ (a) (i) Wurtz reaction (b) (ii) Sandmeyer reaction (c) $^{Ether}C$ (iii) Fittig reaction $-2 CH_{3}CH_{2}Cl + 2Na \rightarrow \rightarrow_{2}H_{5}-C_{2}H_{5}+ 2 NaCl$ $-^{(d)} 2C H Cl + 2Na^{Ether} C H H^{(iv) Gatterman reaction}$ $_{6}_{5}_{6}_{5}-C_{6}_{5}+ 2 NaCl$ Choose the correct answer from the options given below:
Question 51 image
a.
$(a) \rightarrow (iii), \,(b) \rightarrow (\rightarrow \rightarrow \vec{i}v), \,(c) \rightarrow (i), \,(d) \rightarrow (ii)\rightarrow \rightarrow$
b.
$(a) \rightarrow (ii), \,(b) \rightarrow (i), \,(c) \rightarrow (iv), \,(d) \rightarrow (iii)\rightarrow \rightarrow \rightarrow \rightarrow$
c.
$(a) \rightarrow (iii), \,(b) \rightarrow (i), \,(c) \rightarrow (iv), \,(d) \rightarrow (ii)\rightarrow \rightarrow \rightarrow \rightarrow$
d.
$(a) \rightarrow (ii), \,(b) \rightarrow (iv), \,(c) \rightarrow (i), \,(d) \rightarrow (iii)\rightarrow \rightarrow \rightarrow \rightarrow$
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Q52 nat
If the activation energy of a reaction is $80. 9\, kJ \, mol^{-1}$ , the fraction of molecules at $700\,K$ , having enough energy to react to form products is $e^{-x}$ . The value of $x$ is (Rounded off to the nearest integer) [Use $R = 8. 31\,J\,K^{-1}\, mol^{-1}$ ]
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Q53 mcq
Identify $A$ in the given chemical reaction.
Question 53 image
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Q54 mcq
Identify $A$ in the given reaction.
Question 54 image
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Q55 mcq
A. Phenyl methanamine B. $N, \,N$ -Dimethylaniline C. $N$ -Methyl aniline D. Benzenamine Choose the correct order of basic nature of the above amines.
a.
$A > B > C > D$
b.
$A > C > B > D$
c.
$D > B > C > A$
d.
$D > C > B > A$
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Q56 mcq
Identify $A$ in the following chemical reaction.
Question 56 image
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Q57 mcq
Seliwanoff test and Xanthoproteic test are used for the identification of _ and _ respectively.
a.
aldoses, ketoses
b.
ketoses, proteins
c.
proteins, ketoses
d.
ketoses, aldoses
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Q58 mcq
In $CH^{1}_{2} = C =^{2} CH -^{3} CH^{4}_{3}$ molecule, the hybridization of carbon $1, \,2, \,3$ and $4$ respectively, are :
a.
$sp^{2}, \, sp^{3}, \, sp^{2}, \, sp^{3}$
b.
$sp^{2}, \, sp, \, sp^{2}, \, sp^{3}$
c.
$sp^{2}, \, sp^{2}, \, sp^{2}, \, sp^{3}$
d.
$sp^{3}, \, sp, \, sp^{3}, \, sp^{3}$
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Q59 mcq
Considering the above reaction, the major product among the following is:
Question 59 image
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Q60 nat
The $pH$ of ammonium phosphate solution, if $pk_{a}$ of phosphoric acid and $pk_{b}$ of ammonium hydroxide are $5. 23$ and $4. 75$ respectively, is
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Q61 nat
Let $a$ be an integer such that all the real roots of the polynomial $2x^{5} + 5x^{4} + 10x^{3} + 10x^{2} + 10x+ 10$ lie in the interval $(a,a+ 1)$ . Then, $|a|$ is equal to ______.
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Q62 mcq
Let $A_{1}$ be the area of the region bounded by the curves $y= sinx,y= cosx$ and $y$ -axis in the first quadrant. Also, let $A_{2}$ be the area of the region bounded by the curves $y= sinx,y= cosx$ , $x$ -axis and $x= \frac{\pi}{2}$ in the first quadrant. Then,
a.
$2A_{1} =A_{2}$ and $A_{1}+A_{2} = 1 + \sqrt{2}$
b.
$A_{1} :A_{2} = 1 : \sqrt{2}$ and $A_{1}+A_{2} = 1$
c.
$A_{1} :A_{2} = 1 : 2$ and $A_{1}+A_{2} = 1$
d.
$A_{1} =A_{2}$ and $A_{1}+A_{2} = \sqrt{2}$
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Q63 mcq
The triangle of maximum area that can be inscribed in a given circle of radius ' $r$ ' is :
a.
An equilateral triangle having each of its side of length $\sqrt{3}r$ .
b.
An isosceles triangle with base equal to $2r$ .
c.
An equilateral triangle of height $\frac{2r}{3}$ .
d.
A right angle triangle having two of its sides of length $2r$ and $r$ .
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Q64 mcq
Let $f(x)$ be a differentiable function at $x=a$ with $f'(a) = 2$ and $f(a) = 4$ . Then $_{x}lim_{\rightarrow \rightarrow a} \frac{xf(a)-af(x)}{x-a}$ equals:
a.
$a+ 4$
b.
$2a-4$
c.
$4 -2a$
d.
$2a+ 4$
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Q65 nat
The total number of $4$ -digit numbers whose greatest common divisor with $18$ is $3$ is _____.
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Q66 mcq
Let $L$ be a line obtained from the intersection of two planes $x+ 2y+z= 6$ and $y+ 2z= 4$ . If point $P(\alpha ,\beta ,\gamma )$ is the foot of perpendicular from $(3, 2, 1)$ on $L$ , then the value of $21(\alpha +\beta +\gamma )$ equals:
a.
$102$
b.
$142$
c.
$68$
d.
$136$
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Q67 nat
$1 0 0 1 0 0$ $[ ] [ ]$ If the matrix $A= 0 2 0$ satisfies the equation $A^{20} +\alpha A^{19} +\beta A= 0 4 0$ for some real numbers $[3 0 -1] [0 0 1]$ $\alpha$ and $\beta$ , then $\beta - \alpha$ is equal to ______.
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Q68 mcq
$\{2 sin(-\frac{\pi x}{2}), \, if \,x< -1$ Let $f :R\rightarrow \rightarrowR$ be defined as $f(x) = ax^{2} +x+b , \, if \, -1 \leq x\leq 1$ $\{$ $sin(\pi x), \, if \,x> 1$ If $f(x)$ is continuous on $R$ , then $a+b$ equals :
a.
$1$
b.
$3$
c.
$-3$
d.
$-1$
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Q69 mcq
The sum of the series $\sum ^{\infty }_{n=1} \frac{n^{2}+6n+10}{(2n+1)!}$ is equal to
a.
$\frac{41}{8}e+ \frac{19}{8}e^{-1}+ 10$ $-10$
b.
$\frac{41}{8} e+ \frac{19}{8} e^{-1}-10$ $-10$
c.
$-\frac{41}{8} e+ \frac{19}{8} e^{-1}$
d.
$\frac{41}{8} e- \frac{19}{8} e^{-1}$
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Q70 nat
Let $\alpha$ and $\beta$ be two real numbers such that $\alpha +\beta = 1$ and $\alpha \beta = -1$ . Let $p_{n} = (\alpha )^{n} + (\beta )^{n}$ , $p_{n-1} = 11$ and $p_{n+1} = 29$ for some integer $n⩾ 1$ . Then, the value of $p^{2}_{n}$ is______.
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Q71 mcq
Let slope of the tangent line to a curve at any point $P(x,y)$ be given by $\frac{xy^{2}+y}{x}$ . If the curve intersects the line $x+ 2y= 4$ at $x= -2$ , then the value of $y$ , for which the point $(3,y)$ lies on the curve, is :
a.
$-\frac{4}{3}$
b.
$\frac{18}{35}$
c.
$-\frac{18}{19}$
d.
$- \frac{18}{11}$
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Q72 mcq
If the mirror image of the point $(1, 3, 5)$ with respect to the plane $4x-5y+ 2z= 8$ is $(\alpha ,\beta ,\gamma )$ , then $5(\alpha +\beta +\gamma )$ equals :
a.
$43$
b.
$47$
c.
$41$
d.
$39$
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Q73 nat
Let $L$ be a common tangent line to the curves $4x^{2} + 9y^{2} = 36$ and $(2x)^{2} + (2y)^{2} = 31$ . Then the square of the slope of the line $L$ is ______.
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Q74 mcq
Let $A= {1, 2, 3, … , 10}$ and $f :A\rightarrow \rightarrow A$ be defined as $k+ 1 if \,k\,is odd$ $f(k) ={$ $k if \,k\,is even$ Then the number of possible functions $g:A\rightarrow \rightarrow A$ such that $gof =f$ is:
a.
$^{10}C_{5}$
b.
$5^{5}$
c.
$5!$
d.
$10^{5}$
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Q75 mcq
If $0 <a,b< 1$ , and $tan^{-1} a+ tan^{-1} b= \frac{\pi}{4}$ , then the value of $(a+b) - ( \frac{a^{2}+b^{2}}{2} )+( \frac{a^{3}+b^{3}}{3})- (\frac{a^{4}+b^{4}}{4})+ …$ is :
a.
$log_{e}(\frac{e}{2})$
b.
$e$
c.
$e^{2} -1$
d.
$log_{e}2$
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Q76 mcq
A natural number has prime factorization given by $n= 2^{x}3^{y}5^{z}$ , where $y$ and $z$ are such that $y+z= 5$ and $y^{-1} +z^{-1} = \frac{5}{6} ,y>z$ . Then the number of odd divisors of $n$ , including $1$ , is:
a.
$12$
b.
$6$
c.
$11$
d.
$6x$
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Q77 mcq
Let $f(x) =\int _{0}^{x} e^{t}f(t)dt+e^{x}$ be a differentiable function for all $x\in R$ . Then $f(x)$ equals :
a.
$e^{(e^{x}-1)}$
b.
$e^{e^{x}} -1$
c.
$2e^{e^{x}} -1$
d.
$2e^{(e^{x}-1)} -1$
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Q78 mcq
A seven digit number is formed using digits $3, 3, 4, 4, 4, 5, 5$ . The probability, that number so formed is divisible by $2$ , is
a.
$\frac{4}{7}$
b.
$\frac{3}{7}$
c.
$\frac{1}{7}$
d.
$\frac{6}{7}$
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Q79 mcq
Let $F_{1}(A,B,C) = (A\wedge ~B) \vee [~C\wedge (A\vee B)] \vee ~A$ and $F_{2}(A,B) = (A\vee B) \vee (B\rightarrow ~\rightarrow A)$ be two logical expressions. Then :
a.
$F_{1}$ is a tautology but $F_{2}$ is not a tautology
b.
$F_{1}$ is not a tautology but $F_{2}$ is a tautology
c.
Both $F_{1}$ and $F_{2}$ are not tautologies
d.
$F_{1}$ and $F_{2}$ both are tautologies
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Q80 mcq
For $x> 0$ , if $f(x) =\int _{1}^{x} \frac{log_{e}t}{(1+t)}dt$ , then $f(e) +f(\frac{1}{e} )$ is equal to
a.
$0$
b.
$\frac{1}{2}$
c.
$-1$
d.
$1$
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Q81 nat
If $I_{m,n} =\int _{0}^{1} x^{m-1}(1 - x)^{n-1}dx$ , for $m,n⩾ 1$ , and $\int _{0}^{1} \frac{x^{m}^{-1}+x^{n}^{-1}}{(1+x)^{m}^{+}^{n}}dx=\alpha I_{m,n}, \,\alpha \in R$ , then $\alpha$ equals ________.
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Q82 mcq
If the locus of the mid-point of the line segment from the point $(3, 2)$ to a point on the circle, $x^{2} +y^{2} = 1$ is a circle of radius $r$ , then $r$ is equal to
a.
$\frac{1}{4}$
b.
$1$
c.
$\frac{1}{3}$
d.
$\frac{1}{2}$
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Q83 mcq
Let $f(x) = sin^{-1} x$ and $g(x) = \frac{x^{2}-x-2}{2x^{2}-x-6}$ . If $g(2) =_{x}lim_{\rightarrow 2\rightarrow } g(x)$ , then the domain of the function $fog$ is
a.
$(-\infty , -1] \cup [2, \infty )$
b.
$(-\infty , -2]\cup [-\frac{3}{2}, \infty )$
c.
$(-\infty , -2]\cup [-\frac{4}{3} , \infty )$
d.
$(-\infty , -2] \cup [-1, \infty )$
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Q84 mcq
Let $A(1, 4)$ and $B(1, -5)$ be two points. Let $P$ be a point on the circle $((x-1))^{2} + (y-1)^{2} = 1$ , such that $(PA)^{2} + (PB)^{2}$ have maximum value, then the points, $P, \,A$ and $B$ lie on
a.
a hyperbola
b.
a straight line
c.
an ellipse
d.
a parabola
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Q85 mcq
Consider the following system of equations: $x+ 2y-3z=a$ $2x+ 6y-11z=b$ $x-2y+ 7z=c$ where $a,b$ and $c$ are real constants. Then the system of equations :
a.
has a unique solution when $5a= 2b+c$
b.
has no solution for all $a,b$ and $c$
c.
has infinite number of solutions when $5a= 2b+c$
d.
has a unique solution for all $a,b$ and $c$
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Q86 nat
Let $X_{1},X_{2}, … ,X_{18}$ be eighteen observations such that $\sum ^{18}_{i=1}(X_{i}- \alpha ) = 36$ and $\sum ^{18}_{i=1} (X_{i}- \beta )^{2} = 90$ , where $\alpha$ and $\beta$ are distinct real numbers. If the standard deviation of these observations is $1$ , then the value of $|\alpha - \beta |$ is _______.
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Q87 nat
$-^{Let}z^{be those complex numbers which satisfy}|z+ 5| \leq 4^{and}z(1 +i) +z(1 - i)^{⩾} -10,i^{=\sqrt{-1}. If the}$ maximum value of $|z+ 1|^{2}$ is $\alpha +\beta \sqrt{2}$ , then the value of $(\alpha +\beta )$ is
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Q88 mcq
$||$ $--$ If vectors $\vec{a}_{1} =xˆi -ˆj + ˆk$ and $\vec{a}_{2} = ˆi +yˆj +zˆk$ are collinear, then a possible unit vector parallel to the vector $xˆi +yˆj +zˆk$ is:
a.
$\frac{1}{\sqrt{2}} (-ˆj +ˆk)$
b.
$\frac{1}{\sqrt{3}}(ˆi +ˆj - ˆk)$
c.
$\frac{1}{\sqrt{2}} (ˆi -ˆj)$
d.
$\frac{1}{\sqrt{3}}(ˆi -ˆj +ˆk)$
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Q89 nat
Let the normals at all the points on a given curve pass through a fixed point $(a,b)$ . If the curve passes through $(3, -3)$ and $(4, -2\sqrt{2})$ , given that $a-2\sqrt{2}\,b= 3$ , then $(a^{2} +b^{2} +ab)$ is equal to _____.
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Q90 nat
If the arithmetic mean and the geometric mean of the $p^{th}$ and $q^{th}$ terms of the sequence $-16, 8, -4, 2, …$ satisfy the equation $4x^{2} -9x+ 5 = 0$ , then $p+q$ is equal to _______.
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