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JEE Main 2021 (18 Mar Shift 2)

2021 · 90 questions · First 10 Solutions Free
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Q1 mcq
The time taken for the magnetic energy to reach $25%$ of its maximum value, when a solenoid of resistance $R$ , inductance $L$ is connected to a battery, is :
a.
$\frac{L}{R} ln5$
b.
infinite
c.
$\frac{L}{R} ln2$ Correct Answer
d.
$\frac{L}{R}ln10$

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Q2 nat
Consider a $72\, cm$ long wire $AB$ as shown in the figure. The galvanometer jockey is placed at $P$ on $AB$ at a distance $x\, cm$ from $A$ . The galvanometer shows zero deflection. The value of $x$ , to the nearest integer, is
✓ Accepted Answer: 48

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Q3 mcq
A plane electromagnetic wave propagating along y-direction can have the following pair of electric field $(\vec{E})$ and magnetic field $(\vec{B})$ components.
a.
$E_{y},B_{y}$ or $E_{z},B_{z}$
b.
$E_{y},B_{x}$ or $E_{x},B_{y}$
c.
$E_{x},B_{z}$ or $E_{z},B_{x}$ Correct Answer
d.
$E_{x},B_{y}$ or $E_{y},B_{x}$

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Q4 nat
The projectile motion of a particle of mass $5\,g$ is shown in the figure. The initial velocity of the particle is $5\sqrt{2}\, ms^{-1}$ and the air resistance is assumed to be negligible. The magnitude of the change in momentum between the points $A$ and $B$ is $x\times 10^{-2}\, kgms^{-1}$ . The value of $x$ , to the nearest integer, is ___ .
Question 4 image
✓ Accepted Answer: 5

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Q5 nat
A galaxy is moving away from the earth at a speed of $286\, km \,s^{-1}$ . The shift in the wavelength of a red line at $630\, nm$ is $x\times 10^{-10}\,m$ . The value of $x$ , to the nearest integer, is ___ . [Take the value of the speed of the light $c$ , as $3 \times 10^{8}\,m\,s^{-1}$ ]
✓ Accepted Answer: 6

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Q6 mcq
An ideal gas in a cylinder is separated by a piston in such a way that the entropy of one part is $S_{1}$ and that of the other part is $S_{2}$ . Given that $S_{1} >S_{2}$ . If the piston is removed then the total entropy of the system will be:
a.
$S_{1}\times S_{2}$
b.
$S_{1}- S_{2}$
c.
$\frac{S_{1}}{S_{2}}$
d.
$S_{1}+S_{2}$ Correct Answer

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Q7 mcq
A particle of mass $m$ moves in a circular orbit under the central potential field, $U(r) = \frac{-C}{r}$ , where $C$ is a positive constant. The correct radius - velocity graph of the particle's motion is :
Question 7 image

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Q8 mcq
A solid cylinder of mass $m$ is wrapped with an inextensible light string and, is placed on a rough inclined plane as shown in the figure. The frictional force acting between the cylinder and the inclined plane is: [The coefficient of static friction, $\mu _{s}$ , is $0. 4$ ]
Question 8 image
a.
$\frac{7}{2} mg$
b.
$5mg$
c.
$\frac{mg}{5}$ Correct Answer
d.
$0$

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Q9 nat
The typical output characteristics curve for a transistor working in the common-emitter configuration is shown in the figure. The estimated current gain from the figure is
Question 9 image
✓ Accepted Answer: 200

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Q10 mcq
A proton and an $\alpha$ -particle, having kinetic energies $K_{p}$ and $K_{\alpha }$ , respectively, enter into a magnetic field at right angles. The ratio of the radii of the trajectory of proton to that of $\alpha$ -particle is $2 : 1$ . The ratio of $K_{p} :K_{\alpha }$ is:
a.
$1 : 8$
b.
$8 : 1$
c.
$1 : 4$
d.
$4 : 1$ Correct Answer

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Q11 mcq
The function of time representing a simple harmonic motion with a period of $\frac{\pi}{\omega}$ is :
a.
$sin(\omega t) + cos(\omega t)$
b.
$cos(\omega t) + cos(2\omega t) + cos(3\omega t)$
c.
$sin^{2}(\omega t)$
d.
$3 cos(\frac{\pi}{4} -2\omega t)$
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Q12 nat
Consider a water tank as shown in the figure. It's cross-sectional area is $0. 4\,m^{2}$ . The tank has an opening $B$ near the bottom whose cross-section area is $1\, cm^{2}$ . A load of $24\, kg$ is applied on the water at the top when the height of the water level is $40\, cm$ above the bottom, the velocity of water coming out the opening $B$ is $v\,m\,s^{-1}$ . The value of $v$ , to the nearest integer, is ___ .[Take the value of $g$ to be $10\,m\,s^{-2}$ ]
Question 12 image
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Q13 mcq
Which of the following statements are correct? (A) Electric monopoles do not exist whereas magnetic monopoles exist. (B) Magnetic field lines due to a solenoid at its ends and outside cannot be completely straight and confined. (C) Magnetic field lines are completely confined within a toroid. (D) Magnetic field lines inside a bar magnet are not parallel. (E) $χ= -1$ is the condition for a perfect diamagnetic material, where $χ$ is its magnetic susceptibility. Choose the correct answer from the options given below :
a.
(C) and (E) only
b.
(B) and (D) only
c.
(A) and (B) only
d.
(B) and (C) only
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Q14 mcq
In a series LCR circuit, the inductive reactance $(X_{L})$ is $10\,\Omega$ and the capacitive reactance $(X_{C})$ is $4\,\Omega$ . The resistance $(R)$ in the circuit is $6\,\Omega$ . The power factor of the circuit is :
a.
$\frac{1}{2}$
b.
$\frac{1}{2\sqrt{2}}$
c.
$\frac{1}{\sqrt{2}}$
d.
$\frac{\sqrt{3}}{2}$
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Q15 nat
A TV transmission tower antenna is at a height of $20\,m$ . Suppose that the receiving antenna is at. (i) ground level (ii) a height of $5\,m$ . The increase in antenna range in case (ii) relative to case (i) is $n%$ . The value of $n$ , to the nearest integer, is.
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Q16 mcq
For an adiabatic expansion of an ideal gas, the fractional change in its pressure is equal to (where $\gamma$ is the ratio of specific heats):
a.
$-\gamma \frac{dV}{V}$
b.
$-\gamma \frac{V}{dV}$
c.
$- \frac{1}{\gamma} \frac{dV}{V}$
d.
$\frac{dV}{V}$
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Q17 mcq
Three rays of light, namely red $(R)$ , green $(G)$ and blue $(B)$ are incident on the face $PQ$ of a right angled prism $PQR$ as shown in figure. The refractive indices of the material of the prism for red, green and blue wavelength are $1. 27, 1. 42$ and $1. 49$ respectively. The colour of the ray(s) emerging out of the face $PR$ is :
Question 17 image
a.
green
b.
red
c.
blue and green
d.
blue
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Q18 mcq
Consider a sample of oxygen behaving like an ideal gas. At $300\,K$ , the ratio of root-mean-square (RMS) velocity to the average velocity of the gas molecule would be : (Molecular weight of oxygen is $32\,g\, mol^{-1}; \,R= 8. 3\,J\,K^{-1}\, mol^{-1}$ )
a.
$\sqrt{\frac{3}{3}}$
b.
$\sqrt{\frac{8}{3}}$
c.
$\sqrt{\frac{3\pi}{8}}$
d.
$\sqrt{\frac{8\pi}{3}}$
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Q19 nat
Two wires of same length and thickness having specific resistances $6\,\Omega \, cm$ and $3\,\Omega \, cm$ respectively are connected in parallel. The effective resistivity is $\rho$ $\,\Omega cm$ . The value of $\rho$ to the nearest integer, is ___ .
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Q20 nat
An infinite number of point charges, each carrying $1\,\mu C$ charge, are placed along the y-axis at $y= 1\,m, 2\,m, 4\,m, 8\,m\,. . . \,.$ The total force on a $1\,C$ point charge, placed at the origin, is $x\times 10^{3}\,N$ . The value of $x$ , to the nearest integer, is ___ . [Take $\frac{1}{4\pi \epsilon _{0}} = 9 \times 10^{9}\,N\,m^{2}\,C^{-2}$ ]
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Q21 mcq
An object of mass $m_{1}$ collides with another object of mass $m_{2}$ , which is at rest. After the collision the objects move with equal speeds in opposite direction. The ratio of the masses $m_{2} : m_{1}$ is :
a.
$3 : 1$
b.
$2 : 1$
c.
$1 : 2$
d.
$1 : 1$
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Q22 nat
The radius of a sphere is measured to be $(7. 50 \pm 0. 85)\, cm$ . Suppose the percentage error in its volume is $x$ . The value of $x$ , to the nearest $x$ , is ___ .
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Q23 nat
A ball of mass $4\, kg$ , moving with a velocity of $10\,m\,s^{-1}$ , collides with a spring of length $8\,m$ and force constant $100\,N\,m^{-1}$ . The length of the compressed spring is $x\,m$ . The value of $x$ , to the nearest integer, is ___ .
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Q24 mcq
Consider a uniform wire of mass $M$ and length $L$ . It is bent into a semicircle. Its moment of inertia about a line perpendicular to the plane of the wire passing through the centre is :
a.
$\frac{1}{4} \frac{ML^{2}}{\pi ^{2}}$
b.
$\frac{2}{5} \frac{ML^{2}}{\pi ^{2}}$
c.
$\frac{ML^{2}}{\pi ^{2}}$
d.
$\frac{1}{2} \frac{ML^{2}}{\pi ^{2}}$
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Q25 mcq
The correct relation between $\alpha$ (ratio of collector current to emitter current) and $\beta$ (ratio of collector current to base current) of a transistor is :
a.
$\beta = \frac{\alpha}{1+\alpha}$
b.
$\alpha = \frac{\beta}{1-\alpha}$
c.
$\beta = \frac{1}{1-\alpha}$
d.
$\alpha = \frac{\beta}{1+\beta}$
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Q26 mcq
The speed of electrons in a scanning electron microscope is $1 \times 10^{7}\, ms^{-1}$ . If the protons having the same speed are used instead of electrons, then the resolving power of scanning proton microscope will be changed by a factor of:
a.
$1837$
b.
$\frac{1}{1837}$
c.
$\sqrt{1837}$
d.
$\frac{1}{\sqrt{1837}}$
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Q27 mcq
If the angular velocity of earth's spin is increased such that the bodies at the equator start floating, the duration of the day would be approximately : (Take : $g= 10\, ms^{-2}$ , the radius of earth, $R= 6400 \times 10^{3}\,m$ , Take $\pi = 3. 14$ )
a.
$60$ minutes
b.
does not change
c.
$1200$ minutes
d.
$84$ minutes
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Q28 mcq
The velocity-displacement graph of a particle is shown in the figure. The acceleration-displacement graph of the same particle is represented by :
Question 28 image
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Q29 mcq
The decay of a proton to neutron is :
a.
not possible as proton mass is less than the neutron mass
b.
possible only inside the nucleus
c.
not possible but neutron to proton conversion is possible
d.
always possible as it is associated only with $\beta ^{+}$ decay
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Q30 mcq
The angular momentum of a planet of mass $M$ moving around the sun in an elliptical orbit is $\vec{L}$ . The magnitude of the areal velocity of the planet is :
a.
$\frac{4L}{M}$
b.
$\frac{L}{M}$
c.
$\frac{2L}{M}$
d.
$\frac{L}{2M}$
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Q31 mcq
Given below are two statements : Statement I : $C_{2}H_{5}OH$ and $AgCN$ both can generate nucleophile. Statement II : $KCN$ and $AgCN$ both will generate nitrile nucleophile with all reaction conditions. Choose the most appropriate option :
a.
Statement I is true but statement II is false
b.
Both statement I and statement II are true
c.
Statement I is false but statement II is true
d.
Both statement I and statement II are false
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Q32 mcq
In basic medium, $H_{2}O_{2}$ exhibits which of the following reactions? (A) $Mn^{2+} \rightarrow Mn\rightarrow^{4+}$ (B) $I_{2} I^{-}$ (C) $Pb\vec{S}\rightarrow PbSO\rightarrow_{4}$ Choose the most appropriate answer from the options given below :
a.
(A),(C) only
b.
(A) only
c.
(B) only
d.
(A), (B) only
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Q33 mcq
The oxide that shows magnetic property is:
a.
$SiO_{2}$
b.
$Mn_{3}O_{4}$
c.
$Na_{2}O$
d.
$MgO$
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Q34 mcq
Given below are two statements: Statement I : Bohr's theory accounts for the stability and line spectrum of $Li^{+}$ ion. Statement II : Bohr's theory was unable to explain the splitting of spectral lines in the presence of a magnetic field. 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 true.
b.
Statement $I$ is false but statement $II$ is true.
c.
Both statement $I$ and statement $II$ are false.
d.
Statement $I$ is true but statement $II$ is false.
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Q35 mcq
Match list-I with list-II : (a) $Be$ (i) Treatment of cancer (b) $Mg$ (ii) Extraction of metals (c) $Ca$ (iii) Incendiary bombs and signals (d) $Ra$ (iv) Windows of X-ray tubes (v) Bearings for motor engines. Choose the most appropriate answer, the option given below :
a.
$a -iv, \,b -iii, \,c -i, \,d -ii$
b.
$a -iv, b -iii, c -ii, d -i$
c.
$a -iii, \,b -iv, \,c -v, \,d -ii$
d.
$a -iii, \,b -iv, \,c -ii, \,d -v$
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Q36 mcq
The charges on the colloidal $CdS$ sol and $TiO_{2}$ sol are, respectively :
a.
positive and positive
b.
positive and negative
c.
negative and negative
d.
negative and positive
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Q37 nat
The number of species below that have two lone pairs of electrons in their central atom is ___ (Round off to the Nearest integer) $SF_{4}, BF^{-}_{4} , ClF_{3}, AsF_{3}, PCl_{5}, BrF_{5}, XeF_{4}, SF_{6}$
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Q38 nat
The solubility of $CdSO_{4}$ in water is $8. 0 \times 10^{-4}\, mol \,L^{-1}$ . Its solubility in $0. 01M\,H_{2}SO_{4}$ solution is ___ $\times 10^{-6}\, mol \,L^{-1}$ (Round off to the Nearest integer) (Assume that solubility is much less than $0. 01\,M$ )
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Q39 mcq
The first ionization energy of magnesium is smaller, as compared to that of elements $X$ and $Y$ , but higher than that of $Z$ . The elements $X, \,Y$ and $Z$ , respectively, are :
a.
chlorine, lithium and sodium
b.
argon, lithium and sodium
c.
argon, chlorine and sodium
d.
neon, sodium and chlorine
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Q40 nat
Consider the above reaction where $6. 1\,g$ of benzoic acid is used to get $7. 8\,g$ of m-bromo benzoic acid. The percentage yield of the product is ___ . (Round off to the Nearest integer) [Given : Atomic masses : $C = 12. 0\,u, \,H : 1. 0\,u, \,O : 16. 0\,u, \,Br = 80. 0\,u$ ]
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Q41 mcq
Deficiency of vitamin K causes :
a.
Increase in blood clotting time
b.
Increase in fragility of RBC 's
c.
Cheilosis
d.
Decrease in blood clotting time
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Q42 mcq
The oxidation states of nitrogen in $NO, \, NO_{2}, \,N_{2}O$ and $NO^{-}_{3}$ are in the order of :
a.
$NO^{-}_{3} > NO_{2} > NO > N_{2}O$
b.
$NO_{2} > NO^{-}_{3} > NO > N_{2}O$
c.
$N_{2}O > NO_{2} > NO > NO^{-}_{3}$
d.
$NO > NO_{2} > N_{2}O > NO^{-}_{3}$
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Q43 mcq
The secondary valency and the number of hydrogen bonded water molecule(s) in $CuSO_{4}\cdot 5H_{2}O$ , respectively, are
a.
$6$ and $4$
b.
$4$ and $1$
c.
$6$ and $5$
d.
$5$ and $1$
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Q44 nat
A xenon compound $A$ upon partial hydrolysis gives $XeO_{2}F_{2}$ . The number of lone pair of electrons present in compound $A$ is ___ (Round off to the Nearest integer)
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Q45 mcq
Match list-I with list-II : List-I List-II (a) Mercury (i) Vapour phase refining (b) Copper (ii) Distillation refining (c) Silicon (iii) Electrolytic refining (d) Nickel (iv) Zone refining Choose the most appropriate answer from the option given below:
a.
$a -i, \,b -iv, \,c -ii, \,d -iii$
b.
$a -ii, \,b -iii, \,c -i, \,d -iv$
c.
$a -ii, b -iii, c -iv, d -i$
d.
$a -ii, \,b -iv, \,c -iii, \,d -i$
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Q46 mcq
Consider the above reaction, the product $X$ and $Y$ respectively are :
Question 46 image
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Q47 nat
The gas phase reaction $2\,A(g) \rightleftharpoons A_{2}(g)$ at $400\,K$ has $\Delta G^{o} = +25. 2\, kJ \, mol^{-1}$ . The equilibrium constant $K_{C}$ for this reaction is ___ $\times 10^{-2}$ . (Round off to the Nearest integer) Use : $R = 8. 3\,J\, mol^{-1}\,K^{-1}, ln 10 = 2. 3\, log_{10}2 = 0. 30, \,1\,atm = 1\, bar$ antilog $(-0. 3) = 0. 501$
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Q48 mcq
Consider the given reaction, percentage yield of :
a.
$C > A > B$
b.
$B > C > A$
c.
$A > C > B$
d.
$C > B > A$
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Q49 nat
$10. 0\, ml$ of $Na_{2}CO_{3}$ solution is titrated against $0. 2\,M\, HCl$ solution. The following values were obtained in $5$ readings. $4. 8\, ml, 4. 9\, ml, 5. 0\, ml, 5. 0\, ml$ and $5. 0\, ml$ Based on these readings, and convention of titrimetric estimation of concentration of $Na_{2}CO_{3}$ solution is ___ $mM$ . (Round off to the Nearest integer)
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Q50 mcq
Main Products formed during a reaction of $1$ -methoxy naphthalene with hydroiodic acid are:
Question 50 image
a.
and $CH_{3}OH$
b.
and $CH_{3}I$
c.
and $CH_{3}OH$
d.
and $CH_{3}I$
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Q51 nat
The molar conductivity at infinite dilution of barium chloride, sulphuric arid and hydrochloric acid are $280, \,860 426\, Scm^{2} mol^{-1}$ respectively. The molar conductivity at infinite dilution of barium sulphate is ___ $Scm^{2} \, mol^{-1}$ ( Round off to the Nearest Integer).
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Q52 mcq
Match List - I with List - II : List-I (Class of Chemicals) List-II (Example) (a) Antifertility drug (i) Meprobamate (b) Antibiotic (ii) Alitame (c) Tranquilizer (iii) Norethindrone (d) Artificial Sweetener (iv) Salvarsan
a.
$(a) -(ii), \,(b) -(iii), \,(c) -(iv), \,(d) -(i)$
b.
$(a) -(iv), \,(b) -(iii), \,(c) -(ii), \,(d) -(i)$
c.
$(a) -(iii), \,(b) -(iv), \,(c) -(i), \,(d) -(ii)$
d.
$(a) -(ii), \,(b) -(iv), \,(c) -(i), \,(d) -(iii)$
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Q53 mcq
An organic compound $A$ on treatment with benzene sulfonyl chloride gives compound $B$ . $B$ is soluble in dil. $NaOH$ solution. Compound $A$ is :
Question 53 image
a.
$C_{6}H_{5}-N(CH_{3})_{2}$
b.
$C_{6}H_{5}-NHCH_{2}CH_{3}$
c.
$C_{6}H_{5}-CH_{2}NHCH_{3}$
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Q54 mcq
A hard substance melts at high temperature and is an insulator in both solid and in molten state. This solid is most likely to be a / an :
a.
Ionic solid
b.
Molecular solid
c.
Metallic solid
d.
Covalent solid
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Q55 mcq
In the reaction of hypobromite with amide, the carbonyl carbon is lost as:
a.
$CO^{2-}_{3}$
b.
$HCO^{-}_{3}$
c.
$CO_{2}$
d.
$CO$
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Q56 mcq
Given below are two statements : Statement I : Non-biodegradable wastes are generated by the thermal power plants. Statement II : Bio-degradable detergents leads to eutrophication. In the light of the above statements, choose the most appropriate answer from the option given below:
a.
Both statement I and statement II are false
b.
Statement I is true but statement II is false
c.
Statement I is false but statement II is true
d.
Both statement I and statement II are true.
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Q57 mcq
In the following molecules, Hybridisation of carbon $a, b$ and $c$ respectively are :
Question 57 image
a.
$sp^{3}, sp, sp$
b.
$sp^{3}, sp^{2}, sp$
c.
$sp^{3}, sp^{2}, sp^{2}$
d.
$sp^{3}, sp, sp^{2}$
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Q58 nat
In Tollen's test for aldehyde, the overall number of electron(s) transferred to the Tollen's reagent formula $[Ag (NH_{3})_{2}]^{+}$ per aldehyde group to form silver mirror is ___.(Round off to the Nearest integer)
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Q59 nat
A reaction has a half life of $1\, min$ . The time required for $99. 9%$ completion of the reaction is ___ min. (Round off to the Nearest integer) [Use : $ln 2 = 0. 69, ln 10 = 2. 3$ ]
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Q60 nat
A solute $A$ dimerizes in water. The boiling point of a $2$ molal solution of $A$ is $100. 52^{\circ }C$ . The percentage association of $A$ is ___ . (Round off to the Nearest integer) Use : $K_{b}$ for water $= 0. 52\,K\, kg \, mol^{-1}$ Boiling point of water $= 100^{\circ}C$
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Q61 mcq
If $P$ and $Q$ are two statements, then which of the following compound statement is a tautology?
a.
$((P \Rightarrow Q) \wedge ~Q) \Rightarrow Q$
b.
$((P \Rightarrow Q) \wedge ~Q) \Rightarrow ~P$
c.
$((P \Rightarrow Q) \wedge ~Q) \Rightarrow P$
d.
$((P \Rightarrow Q) \wedge ~Q) \Rightarrow (P \wedge Q)$
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Q62 mcq
Let $f\, : \,R R$ be a function defined as $\{\frac{si\vec{n}(a+1)x+sin 2x}{2x} ,if x< 0$ $f(x) = b , if \,x= 0$ $\{$ $\frac{\sqrt{x+bx^{3}}-\sqrt{x}}{bx^{5/2}} , if \,x> 0$ If $f$ is continuous at $x= 0$ , then the value of $a+b$ is equal to :
a.
$-\frac{5}{2}$
b.
$-2$
c.
$-3$
d.
$- \frac{3}{2}$
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Q63 mcq
Let $S_{1}$ be the sum of first $2n$ terms of an arithmetic progression. Let $S_{2}$ be the sum of first $4n$ terms of the same arithmetic progression. If $(S_{2}- S_{1})$ is $1000$ , then the sum of the first $6n$ terms of the arithmetic progression is equal to:
a.
$1000$
b.
$7000$
c.
$5000$
d.
$3000$
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Q64 nat
Let the mirror image of the point $(1, 3,a)$ with respect to the plane $\vec{r}\cdot (2ˆi-ˆj+ˆk)- b= 0$ be $(-3, 5, 2)$ . Then the value of $|a+ b|$ is equal to ___ .
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Q65 mcq
Let the centroid of an equilateral triangle $ABC$ be at the origin. Let one of the sides of the equilateral triangle be along the straight line $x+y= 3$ . If $R$ and $r$ be the radius of circumcircle and incircle respectively of $\Delta ABC$ , then $(R+r)$ is equal to :
a.
$\frac{9}{\sqrt{2}}$
b.
$7\sqrt{2}$
c.
$2\sqrt{2}$
d.
$3\sqrt{2}$
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Q66 mcq
Consider a hyperbola $H\, : \,x^{2} -2y^{2} = 4$ . Let the tangent at a point $P(4, \sqrt{6})$ meet the $x$ -axis at $Q$ and latus rectum at $R(x_{1},y_{1}),x_{1} > 0$ . If $F$ is a focus of $H$ which is nearer to the point $P$ , then the area of $\Delta QFR$ (in sq. units) is equal to
a.
$4\sqrt{6}$
b.
$\sqrt{6}-1$
c.
$\frac{7}{\sqrt{6}} -2$
d.
$4 -1\sqrt{6}$
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Q67 nat
Let $^{n}C_{r}$ denote the binomial coefficient of $x^{r}$ in the expansion of $(1 +x)^{n}$ . If $\sum ^{10}_{k=0}(2^{2}+ 3k)^{n}C_{k} =\alpha . 3^{10}+\beta \cdot 2^{10}, \,\alpha , \,\beta \in R$ , then $\alpha +\beta$ is equal to ___ .
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Q68 nat
The term independent of $x$ in the expansion of $[\frac{x+1}{x^{2/3}-x^{1/3}+1} - \frac{x-1}{x-x^{1/2}}]^{10}, \,x\neq 1$ , is equal to ___.
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Q69 nat
$2 -1$ Let $I$ be an identity matrix of order $2 \times 2$ and $P =[ ]$ . Then the value of $n\in N$ for which $5 -3$ $P^{n} = 5I-8P$ is equal to ___ .
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Q70 mcq
Let $y=y(x)$ be the solution of the differential equation $\frac{dy}{dx} = (y+ 1)((y+ 1)e^{x^{2}/2}- x), 0 <x< 2. 1$ , with $y(2) = 0$ . Then the value of $\frac{dy}{dx}$ at $x= 1$ is equal to
a.
$\frac{-e^{3/2}}{(e^{2}+1)^{2}}$
b.
$- \frac{2e^{2}}{(1+e^{2})^{2}}$
c.
$\frac{e^{5/2}}{(1+e^{2})^{2}}$
d.
$\frac{5e^{1/2}}{(e^{2}+1)^{2}}$
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Q71 mcq
Let $f :R-{3} \rightarrow \rightarrow R-{1}$ be defined by $f(x) = \frac{x-2}{x-3}$ . Let $g\, : \,R\rightarrow \rightarrow R$ be given as $g(x) = 2x-3$ . Then, the sum of all the values of $x$ for which $f^{-1}(x) +g^{-1}(x) = \frac{13}{2}$ is equal to
a.
$7$
b.
$2$
c.
$5$
d.
$3$
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Q72 nat
Let $f\, : \,R \rightarrow R\rightarrow$ satisfy the equation $f(x+y) =f(x) \cdot f(y)$ for all $x,y\in R$ and $f(x) \neq 0$ for any $x\in R$ . If the function $f$ is differentiable at $x= 0$ and $f'(0) = 3$ , then $_{h}lim_{0} \frac{1}{h} (f(h) -1)$ is equal to ___ .
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Q73 mcq
Let a complex number be $w= 1 - \sqrt{3}i$ . Let another complex number $z$ be such that $|zw| = 1$ and $arg(z) -arg(w) = \frac{\pi}{2}$ . Then the area of the triangle (in sq. units) with vertices origin, $z$ and $w$ is equal to
a.
$4$
b.
$\frac{1}{2}$
c.
$\frac{1}{4}$
d.
$2$
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Q74 mcq
A pole stands vertically inside a triangular park $ABC$ . Let the angle of elevation of the top of the pole from each corner of the park be $\frac{\pi}{3}$ . If the radius of the circumcircle of $\Delta ABC$ is $2$ , then the height of the pole is equal to :
a.
$\frac{2\sqrt{3}}{3}$
b.
$2\sqrt{3}$
c.
$\sqrt{3}$
d.
$\frac{1}{\sqrt{3}}$
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Q75 nat
Let $P$ be a plane containing the line $\frac{x-1}{3} = \frac{y+6}{4} = \frac{z+5}{2}$ and parallel to the line $\frac{x-3}{4} = \frac{y-2}{-3} = \frac{z+5}{7}$ . If the point $(1, -1,\alpha )$ lies on the plane $P$ , then the value of $|5\alpha |$ is equal to ___ .
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Q76 mcq
$| || || |$ $|| |||$ Let $\vec{a}$ and $\vec{b}$ be two non-zero vectors perpendicular to each other and $\vec{a} = \vec{b}$ , If $\vec{a}\times \vec{b} = \vec{a}$ , then the angle between the vectors $(\vec{a}+ \vec{b}+(\vec{a}\times \vec{b}))$ and $\vec{a}$ is equal to :
a.
$sin^{-1}(\frac{1}{\sqrt{3}})$
b.
$cos^{-1}(\frac{1}{\sqrt{3}} )$
c.
$cos^{-1}( \frac{1}{\sqrt{2}})$
d.
$sin^{-1}( \frac{1}{\sqrt{6}})$
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Q77 mcq
Let in a Binomial distribution, consisting of $5$ independent trials, probabilities of exactly $1$ and $2$ successes be $0. 4096$ and $0. 2048$ respectively. Then the probability of getting exactly $3$ successes is equal to :
a.
$\frac{32}{625}$
b.
$\frac{80}{243}$
c.
$\frac{40}{243}$
d.
$\frac{128}{625}$
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Q78 nat
Let $P(x)$ be a real polynomial of degree $3$ which vanishes at $\vec{x}= -3$ . Let $P(x)$ have local minima at $x= 1$ , local maxima at $x= -1$ and $\int _{-1}^{1} P(x)dx= 18$ , then the sum of all the coefficients of the polynomial $P(x)$ is equal to ___ .
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Q79 nat
If $\sum ^{10}_{r=1} r!(r^{3}+ 6r^{2}+ 2r+ 5)=\alpha (11!)$ , then the value of $\alpha$ is equal to ___ .
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Q80 mcq
The area (in sq. unit) bounded by the curve $4y^{2} =x^{2}(4 - x)(x-2)$ is equal to
a.
$\frac{\pi}{8}$
b.
$\frac{3\pi}{8}$
c.
$\frac{3\pi}{2}$
d.
$\frac{\pi}{16}$
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Q81 nat
Let $y=y(x)$ be the solution of the differential equation $xdy- ydx=\sqrt{(x^{2}-y^{2})}dx, \,x\geq 1$ , with $y(1) = 0$ . If the area bounded by the line $x= 1,x=e^{\pi },y= 0$ and $y=y(x)$ is $\alpha e^{2\pi } +\beta ,$ then the value of $10(\alpha +\beta )$ is equal to ___ .
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Q82 mcq
Let in a series of $2n$ observations, half of them are equal to $a$ and remaining half are equal to $-a$ . Also by adding a constant $b$ in each of these observations, the mean and standard deviation of new set become $5$ and $20$ , respectively. Then the value of $a^{2} +b^{2}$ is equal to :
a.
$425$
b.
$650$
c.
$250$
d.
$925$
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Q83 mcq
Define a relation $R$ over a class of $n\times n$ real matrices $A$ and $B$ as " $ARB$ iff there exists a non-singular matrix $P$ such that $PAP^{-1} =B$ ". Then which of the following is true ?
a.
$R$ is symmetric, transitive but not reflexive
b.
$R$ is reflexive, symmetric but not transitive
c.
$R$ is an equivalence relation
d.
$R$ is reflexive, transitive but not symmetric
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Q84 mcq
$-----$ In a triangle $ABC$ , if $B\vec{C} = 8, C\vec{A} = 7, A\vec{B} = 10$ , then the projection of the vector $A\vec{B}$ on $A\vec{C}$ is equal to :
a.
$\frac{25}{4}$
b.
$\frac{85}{14}$
c.
$\frac{127}{20}$
d.
$\frac{115}{16}$
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Q85 mcq
If $15 sin^{4} \alpha + 10 cos^{4} \alpha = 6,$ for some $\alpha \in R,$ then the value of $27 sec^{6} \alpha + 8 cosec^{6} \alpha$ is equal to :
a.
$350$
b.
$500$
c.
$400$
d.
$250$
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Q86 mcq
Let a tangent be drawn to the ellipse $\frac{x^{2}}{27} +y^{2} = 1$ at $(3\sqrt{3}cos\theta , sin\theta )$ where $\theta \in (0, \frac{\pi}{2} )$ . Then the value of $\theta$ such that the sum of intercepts on axes made by this tangent is minimum is equal to :
a.
$\frac{\pi}{8}$
b.
$\frac{\pi}{4}$
c.
$\frac{\pi}{6}$
d.
$\frac{\pi}{3}$
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Q87 mcq
Let $S_{1}\, : \,x^{2} +y^{2} = 9$ and $S_{2}\, : \,(x-2)^{2} +y^{2} = 1$ . Then the locus of center of a variable circle $S$ which touches $S_{1}$ internally and $S_{2}$ externally always passes through the points :
a.
$(0, \pm \sqrt{3})$
b.
$(\frac{1}{2}, \pm \frac{\sqrt{5}}{2})$
c.
$(2, \pm \frac{3}{2})$
d.
$(1, \pm 2)$
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Q88 mcq
Let $g(x) =\int _{0}^{x} f(t)dt$ , where $f$ is continuous function in $[0, 3]$ such that $\frac{1}{3} \leq f(t) \leq 1$ for all $t\in [0, 1]$ and $0 \leq f(t) \leq \frac{1}{2}$ for all $t\in (1, 3]$ . The largest possible interval in which $g(3)$ lies is :
a.
$[-1, - \frac{1}{2}]$
b.
$[- \frac{3}{2}, -1]$
c.
$[ \frac{1}{3}, 2]$
d.
$[1, 3]$
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Q89 nat
If $f(x)$ and $g(x)$ are two polynomials such that the polynomial $P(x)=f(x^{3})+xg(x^{3})$ is divisible by $x^{2} +x+ 1$ , then $P(1)$ is equal to ___ .
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Q90 mcq
Let the system of linear equations $4x+\lambda y+ 2z= 0$ $2x- y+z= 0$ $\mu x+ 2y+ 3z= 0, \,\lambda , \,\mu \in R$ has a non-trivial solution. Then which of the following is true?
a.
$\mu = 6, \,\lambda \in R$
b.
$\lambda = 2, \,\mu \in R$
c.
$\lambda = 3, \,\mu \in R$
d.
$\mu = -6, \,\lambda \in R$
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