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JEE Main 2020 (05 Sep Shift 2)

2020 · 75 questions · First 10 Solutions Free
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Q1 mcq
The correct match between the entries in column I and column II are : I II Radiation Wavelength a Microwave i $100\,m$ b Gamma rays ii $10^{-15}m$ c A.M. radio iii $10^{-10}m$ d X-rays iv $10^{-3}m$
a.
(a)-(ii), (b) - (i), (c) - (iv), (d) - (iii)
b.
(a)-(i), (b) - (iii), (c) - (iv), (d) - (ii)
c.
(a)-(iii), (b) - (ii), (c) - (i), (d) - (iv)
d.
(a)-(iv), (b) - (ii), (c) - (i), (d) - (iii) Correct Answer

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Q2 mcq
Two Zener diodes ( $A$ and $B$ ) having breakdown voltages of $6\,V$ and $4\,V$ respectively, are connected as shown in the circuit below. The output voltage $V_{0}$ variation with input voltage linearly increasing with time, is given by ( $V_{input}\, = \,0V at t\, = \,0$ )
Question 2 image

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Q3 nat
A prism of angle $A= 1^{\circ}\mu = 1. 5$ . A good estimate for the minimum angle of deviation (in degrees) is close to $\frac{N}{10} .$ Value of $N$ is $… … …$
✓ Accepted Answer: 5

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Q4 mcq
Two different wires having lengths $L_{1}$ and $L_{2}$ and respective temperature coefficient of linear expansion $\alpha _{1}$ and $\alpha _{2},$ are joined end-to-end. Then the effective temperature coefficient of linear expansion is :
a.
$\frac{\alpha _{1}L_{1}+\alpha _{2}L_{2}}{L_{1}+L_{2}}$ Correct Answer
b.
$2\sqrt{\alpha _{1}\alpha _{2}}$
c.
$\frac{\alpha +\alpha}{2}^{1}^{2}$
d.
$4 \frac{\alpha \alpha}{\alpha _{1}+\alpha _{2}}^{1}^{2} \frac{LL}{(L_{2}+L_{1})^{2}}^{2}^{1}$

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Q5 mcq
A ring is hung on a nail. It can oscillate, without slipping or sliding (i) in its plane with a time period $T_{1}$ and (ii) back and forth in a direction perpendicular to its plane, with a period $T_{2}$ . The ratio $\frac{T_{1}}{T_{2}}$ will be :
a.
$\frac{2}{\sqrt{3}}$ Correct Answer
b.
$\frac{2}{3}$
c.
$\frac{3}{\sqrt{2}}$
d.
$\frac{\sqrt{2}}{3}$

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Q6 mcq
Two coherent sources of sound, $S_{1}$ and $S_{2},$ produce sound waves of the same wavelength $\lambda = 1\,m$ are in phase. $S_{1}$ and $S_{2}$ are placed $1. 5\,m$ apart (see fig). A listener, located at $L$ , directly in front of $S_{2}$ , finds that the intensity is at a minimum when he is $2\,m$ away from $S_{2}$ . The listener moves away from $S_{1}$ , keeping the distance from $S_{2}$ fixed. The adjacent maximum of intensity is observed when the listener is at a distance $d$ from $S_{1}$ . Then $d$ is :
Question 6 image
a.
$12m$
b.
$5m$ Correct Answer
c.
$2m$
d.
$3m$

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Q7 mcq
A spaceship in space sweeps stationary interplanetary dust. As a result, its mass increases at a rate $\frac{dM(t)}{dt} =bv^{2}(t),$ where $v(t)$ is its instantaneous velocity. The instantaneous acceleration of the satellite is:
a.
$-bv^{3}(t)$
b.
$\frac{-bv^{3}}{M(t)}$ Correct Answer
c.
$- \frac{2bv^{3}}{M(t)}$
d.
$- \frac{bv^{3}}{2M(t)}$

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Q8 mcq
The acceleration due to gravity on the earth's surface at the poles is $g$ and angular velocity of the earth about the axis passing through the pole is $\omega$ . An object is weighed at the equator and at a height $h$ above the poles by using a spring balance. If the weights are found to be same, then $h$ is: ( $h\ll R$ , where $R$ is the radius of the earth)
a.
$\frac{R^{2}\omega ^{2}}{2g}$ Correct Answer
b.
$\frac{R^{2}\omega ^{2}}{g}$
c.
$\frac{R^{2}\omega ^{2}}{4g}$
d.
$\frac{R^{2}\omega ^{2}}{8g}$

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Q9 mcq
A galvanometer is used in laboratory for detecting the null point in electrical experiments. If, on passing a current of $6mA$ it produces a deflection of $2^{\circ}$ , its figure of merit is close to :
a.
$333^{\circ}\,A/div$
b.
$6 \times 10^{-3}A/ div$
c.
$\,666^{\circ}\,A/div.$
d.
$3 \times 10^{-3}A/ div$ Correct Answer

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Q10 mcq
A parallel plate capacitor has plate of length $l$ , width $w$ and separation of plates is $d$ . It is connected to a battery of emf $V$ . A dielectric slab of the same thickness $d$ and of dielectric constant $K = 4$ is being inserted between the plates of the capacitor. At what length of the slab inside plates, will the energy stored in the capacitor be two times the initial energy stored?
a.
$\frac{2l}{3}$
b.
$\frac{l}{3}$ Correct Answer
c.
$\frac{l}{4}$
d.
$\frac{l}{2}$

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Q11 nat
Nitrogen gas is at $300\,^{\circ}C$ temperature. The temperature (in $K$ ) at which the rms speed of a $H_{2}$ molecule would be equal to the rms speed of a nitrogen molecule, is $… … … .$ (Molar mass of $N_{2}$ gas $28\,g$ ).
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Q12 mcq
An iron rod of volume $10^{-3}\,m^{3}$ and relative permeability $1000$ is placed as core in a solenoid with $10\, turns \, cm^{-1}$ . If a current of $0. 5\,A$ is passed through the solenoid, then the magnetic moment of the rod will be :
a.
$50 \times 10^{2} Am^{2}$
b.
$5 \times 10^{2} Am^{2}$
c.
$500 \times 10^{2} Am^{2}$
d.
$0. 5 \times 10^{2} Am^{2}$
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Q13 mcq
A driver in a car, approaching a vertical wall notices that the frequency of his car horn has changed from $440\, Hz$ to $480\, Hz$ , when it gets reflected from the wall. If the speed of sound in air is $345\,m\,s^{-1}$ , then the speed of the car is:
a.
$54\,km/hr$
b.
$36\,km/hr$
c.
$18\,km/hr$
d.
$24\,km/hr$
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Q14 mcq
In the circuit shown, charge on the $5\mu F$ capacitor is :
Question 14 image
a.
$18. 00\mu C$
b.
$10. 90\mu C$
c.
$16. 36\mu C$
d.
$5. 45\mu C$
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Q15 mcq
Ten charges are placed on the circumference of a circle of radius R with constant angular separation between successive charges. Alternate charges $1, 3, 5, 7, 9$ have charge $(+q)$ each, while $2, 4, 6, 8, 10$ have charge $(-q)$ each. The potential V and the electric field E at the centre of the circle are respectively : (Take $V = 0$ at infinity)
a.
$V = \frac{10q}{4\pi \epsilon _{0}R};E = 0$
b.
$V = 0, E = \frac{10q}{4\pi \epsilon _{0}R^{2}}$
c.
$V = 0; \,E = 0$
d.
$V = \frac{10q}{4\pi \epsilon _{0}R} ;E = \frac{10q}{4\pi \epsilon _{0}R^{2}}$
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Q16 mcq
In the circuit, given in the figure currents in different branches and value of one resistor are shown. Then potential at point $B$ with respect to the point $A$ is:
Question 16 image
a.
$+2V$
b.
$-2V$
c.
$-1V$
d.
$+1V$
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Q17 mcq
An infinitely long straight wire carrying current I, one side opened rectangular loop and a conductor $C$ with a sliding connector are located in the same plane, as shown in the figure. The connector has length l. and resistance $R$ . It slides to the right with a velocity $v$ . The resistance of the conductor and the self inductance of the loop are negligible. The induced current in the loop, as a function of separation r, between the connector and the straight wire is
Question 17 image
a.
$\frac{\mu _{0}}{4\pi} \frac{Iv \ell}{Rr}$
b.
$\frac{\mu _{0}}{\pi} \frac{Iv \ell}{Rr}$
c.
$\frac{2\mu _{0}}{\pi} \frac{Iv \ell}{Rr}$
d.
$\frac{\mu _{0}}{2\pi} \frac{Iv \ell}{Rr}$
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Q18 nat
A thin rod of mass $0. 9\, kg$ and length $1\,m$ is suspended, at rest, from one end so that it can freely oscillate in the vertical plane. A particle of move $0. 1\, kg$ moving in a straight line with velocity $80\,m\,s^{-1}$ hits the rod at its bottom most point and sticks to it (see figure). The angular speed (in $rad \,s^{-1}$ ) of the rod immediately after the collision will be …………
Question 18 image
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Q19 mcq
The velocity $(v)$ and time $(t)$ graph of a body in a straight line motion is shown in the figure. The point $S$ is at $4. 333$ seconds. The total distance covered by the body in $6\,s$ is :
Question 19 image
a.
$\frac{37}{3}m$
b.
$12m$
c.
$11m$
d.
$\frac{49}{4}m$
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Q20 mcq
In an experiment to verify Stokes law, a small spherical ball of radius $r$ and density $\rho$ falls under gravity through a distance $h$ in air before entering a tank of water. If the terminal velocity of the ball inside water is same as its velocity just before entering the water surface, then the value of $h$ is proportional to: (ignore viscosity of air)
a.
$r^{4}$
b.
$r$
c.
$r^{3}$
d.
$r^{2}$
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Q21 nat
The surface of a metal is illuminated alternately with photons of energies $E_{1}= 4\, eV$ and $E_{2}= 2. 5\, eV$ respectively. The ratio of maximum speeds of the photoelectrons emitted in the two cases is $2.$ The work function of the metal in $(eV)$ is..........
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Q22 mcq
The quantities $x=_{\sqrt{\mu _{0}\in _{0}}} ,y=_{B}$ and $z=_{CR}$ are defined where C-capacitance, R-Resistance, $\ell -$ length, E- Electric field, B-magnetic field and $\in 0, \,\mu 0, -$ free space permittivity and permeability respectively. Then:
a.
x, y and z have the same dimension.
b.
Only x and z have the same dimension
c.
Only x and y have the same dimension
d.
Only y and z have the same dimension.
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Q23 mcq
A radioactive nucleus decays by two different processes. The half-life for the first process is $10\,s$ and that for the second is $100\,s$ . The effective half-life of the nucleus is close to:
a.
$9\,s$
b.
$6\,s$
c.
$55\,s$
d.
$12\,s$
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Q24 nat
A body of mass $2\, kg$ is driven by an engine delivering a constant power of $1\,J\,s^{-1}$ . the body starts from rest and moves in a straight line. After $9\,s$ , the body has moved a distance (in $m$ )….
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Q25 mcq
In an adiabatic process, the density of a diatomic gas becomes $32n$ times its initial value. The final pressure of the gas is found to be $n$ times the initial pressure. The value of $n$ is:
a.
$32$
b.
$326$
c.
$128$
d.
$\frac{1}{32}$
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Q26 mcq
Among the following compounds, geometrical isomerism is exhibited by :
Question 26 image
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Q27 mcq
Lattice enthalpy and enthalpy of solution of $NaCl$ are $788 kJmol^{-1}$ and $4kJmol^{-1}$ , respectively. The hydration enthalpy of $NaCl$ is:
a.
$-780 kJmol^{-1}$
b.
$780 kJmol^{-1}$
c.
$-784 kJmol^{-1}$
d.
$784 kJmol^{-1}$
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Q28 mcq
Boron and silicon of very high purity can be obtained through :
a.
liquation
b.
zone refining
c.
vapour phase refining
d.
electrolytic refining
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Q29 mcq
Reaction of ammonia with excess $Cl_{2}$ gives :
a.
$NH_{4}Cl \,and\,N_{2}$
b.
$NH_{4}Cl \,and\, HCl$
c.
$NCl_{3}\,and\, NH_{4}Cl$
d.
$NCl_{3}\,and\, HCl$
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Q30 mcq
The following molecule acts as an :
Question 30 image
a.
Antiseptic
b.
Anti-depressant
c.
Anti-bacterial
d.
Anti-histamine
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Q31 mcq
Hydrogen peroxide, in the pure state, is :
a.
non-planar and almost colorless
b.
Linear and blue in color
c.
Linear and almost colorless
d.
planar and blue in color
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Q32 nat
The volume, in $mL$ , of $0. 02 MK_{2}Cr_{2}O_{7}$ , solution required to react with $0. 288g$ of ferrous oxalate in acidic medium is $… … … …$ (Molar mass of $Fe = 56 gmol^{-1}$ )
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Q33 mcq
The correct statement about probability density (except at infinite distance from nucleus) is :
a.
It can be zero for 1s orbital
b.
It can be negative for 2p orbital
c.
It can be zero for 3p orbital
d.
It can never be zero for 2s orbital
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Q34 mcq
Which one of the following polymers is not obtained by condensation polymerisation ?
a.
Nylon 6, 6
b.
Buna - N
c.
Bakelite
d.
Nylon 6
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Q35 mcq
The final major product of the following reaction is :
Question 35 image
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Q36 nat
For a reaction $X+Y = 2Z, 1. 0 mol$ of $X, 1. 5 mol$ of $Y$ and $0. 5 mol$ of $Z$ were taken in a $1L$ vessel and allowed to react. At equilibrium, the concentration of $Z$ was $1. 0 molL^{-1}$ . the equilibrium constant of the reaction is $… … … … \frac{x}{15}.$ The value of x is $… … .$
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Q37 mcq
Adsorption of a gas follows Freudlich adsorption isotherm. If $x$ is the mass of the gas adsorbed on mass $m$ of the adsorbent, the correct plot of $\frac{x}{m}$ versus p is:
Question 37 image
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Q38 mcq
The rate constant $(k)$ of a reaction is measured at different temperature $(T)$ , and the data are plotted in the given figure. the activation energy of the reaction in $kJmol^{-1}$ is : $(R$ is gas constant)
a.
$2/R$
b.
$1/R$
c.
$R$
d.
$2R$
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Q39 mcq
The compound that has the largest $H-M-H$ bond angle $(M\, = \,N, \,O, \,S, \,C)$ , is :
a.
$H_{2}O$
b.
$NH_{3}$
c.
$H_{2}S$
d.
$CH_{4}$
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Q40 mcq
The major product of the following reaction is :
Question 40 image
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Q41 nat
Considering that $\Delta _{0}>P$ , the magnetic moment (in BM) of $[Ru (H_{2}O)_{6}]^{2+}$ would be
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Q42 mcq
The major product formed in the following reaction is : $-CH_{2}CH = CHCH (CH_{3})_{2}^{HBr}$
a.
$CH_{3}CH_{2}CH(Br) CH (C\vec{H}_{3})_{2}$
b.
$CH_{3}CH(Br) CH_{2}CH (CH_{3})_{2}$
c.
$Br (CH_{2})_{3}CH (CH_{3})_{2}$
d.
$CH_{3}CH_{2}CH_{2}C(Br)(CH_{3})_{2}$
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Q43 nat
For a dimerization reaction, $2A(g) \rightarrow A\rightarrow_{2}(g)$ at $298K,\Delta U^{-} = -20 kJmol^{-1},\Delta S^{-} = -30 JK^{-1} mol^{-1}$ ,then the $\Delta G^{-}$ will be …..J.
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Q44 mcq
Consider the complex ions, trans- $[Co(en)_{2}Cl_{2}]^{*}(A)$ and $cis -[Co(en)_{2}Cl_{2}]^{+}(B).$ The correct statement regarding them is :
a.
both (A) and (B) cannot be optically active.
b.
(A) can be optically active, but (B) cannot be optically active.
c.
both (A) and (B) can be optically active.
d.
(A) cannot be optically active, but (B) can be optically active.
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Q45 mcq
The correct order of the ionic radii of $O^{2-}, N^{3-}, F^{-}, Mg^{2+}, Na^{+}$ and $Al^{3+}$ is :
a.
$N^{3-} < O^{2-} < F^{-} < Na^{+} < Mg^{2*} < AI^{3+}$
b.
$AI^{3+} < Na^{+} < Mg^{2+} < O^{2-} < F^{-} < N^{3-}$
c.
$Al^{3+} < Mg^{2+} < Na^{+} < F^{-} < O^{2-} < N^{3-}$
d.
$N^{3-} < F^{-} < O^{2-} < Mg^{2+} < Na^{+} < AI^{3+}$
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Q46 mcq
The variation of molar conductively with concentration of an electrolyte (X) in aqueous solution is shown in the given figure. The electrolyte X is :
Question 46 image
a.
$HCl$
b.
$NaCl$
c.
$KNO_{3}$
d.
$CH_{3}COOH$
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Q47 nat
The number of chiral carbons present in sucrose is ……….
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Q48 mcq
The one that is NOT suitable for the removal of permanent hardness of water is :
a.
Clark's method
b.
Ion-exchange method
c.
Calgon's method
d.
Treatment with sodium carbonate
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Q49 mcq
The increasing order of boiling points of the following compounds is :
Question 49 image
a.
I < III < IV < II
b.
I < IV < II< III
c.
IV < I < II < III
d.
III < I < II < IV
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Q50 mcq
An element crystallises in a face-centred cubic (fcc) unit cell with cell edge a. The distance between the centres of two nearest octahedral voids in the crystal lattice is:
a.
$\frac{a}{\sqrt{2}}$
b.
$a$
c.
$\sqrt{2}a$
d.
$\frac{a}{2}$
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Q51 nat
Let $A= {a,b,c}$ and $B= {1, 2, 3, 4}.$ Then the number of elements in the set $C = {f :A\rightarrow \rightarrow B|2 \in f(A)$ and $f$ is not one-one $}$ is $…$
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Q52 mcq
If $L= sin^{2}( \frac{\pi}{16})-sin^{2}( \frac{\pi}{8})$ and $M = cos^{2}(\frac{\pi}{16})-sin^{2}(\frac{\pi}{8})$
a.
$L= - \frac{1}{2\sqrt{2}} + \frac{1}{2}cos \frac{\pi}{8}$
b.
$L= \frac{1}{4\sqrt{2}} - \frac{1}{4}cos \frac{\pi}{8}$
c.
$M = \frac{1}{4\sqrt{2}} + \frac{1}{4}cos \frac{\pi}{8}$
d.
$M = \frac{1}{2\sqrt{2}} + \frac{1}{2} cos \frac{\pi}{8}$
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Q53 nat
$||$ $|| |$ $||$ In a bombing attack, there is $50%$ chance that a bomb will hit the target. At least two independent hits are required to destroy the target completely. Then the minimum number of bombs, that must be dropped to ensure that there is at least $99%$ chance of completely destroying the target, is $. . . . .$
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Q54 mcq
$| |$ Which of the following points lies on the tangent to the curve $x^{4}e^{y} + 2\sqrt{y+ 1}= 3$ at the point $(1, 0)$ ?
a.
$(2, \,2)$
b.
$(2, \,6)$
c.
$(-2, \,6)$
d.
$(-2, \,4)$
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Q55 mcq
If the sum of the second, third and fourth terms of a positive term G.P. is $3$ and the sum of its sixth, seventh and eighth terms is $243$ , then the sum of the first $50$ terms of this G.P. is :
a.
$\frac{1}{26}(3^{49}-1)$
b.
$\frac{1}{26} (3^{50}-1)$
c.
$\frac{2}{13}(3^{50}-1)$
d.
$\frac{1}{13} (3^{50}-1)$
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Q56 mcq
The area (in sq. units) of the region $A={(x,y):(x-1)[x]\leq y\leq 2\sqrt{x}, 0 \leq x\leq 2},$ where $[t]$ denotes the greatest integer function, is :
a.
$\frac{8}{3}\sqrt{2}- \frac{1}{2}$
b.
$\frac{4}{3}\sqrt{2}+ 1$
c.
$\frac{8}{3}\sqrt{2}-1$
d.
$\frac{4}{3}\sqrt{2}- \frac{1}{2}$
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Q57 mcq
The value of $(\frac{-1+i\sqrt{3}}{1-i} )^{30}$ is :
a.
$6^{5}$
b.
$2^{15}$ i
c.
$-2^{15}$
d.
$-2^{15}$ i
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Q58 mcq
If $\alpha$ and $\beta$ are the roots of the equation, $7x^{2} -3x-2 = 0,$ then the value of $\frac{\alpha}{1-\alpha ^{2}} + \frac{\beta}{1-\beta ^{2}}$ is equal to:
a.
$\frac{27}{32}$
b.
$\frac{1}{24}$
c.
$\frac{3}{8}$
d.
$\frac{27}{16}$
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Q59 nat
Let the vectors $\vec{a}, \vec{b}, \vec{c}$ be such that $\vec{a} = 2, \vec{b} = 4$ and $\vec{c} = 4.$ If the projection of $\vec{b}$ on $\vec{a}$ is equal to the projection of $\vec{c}$ on $\vec{a}$ and $\vec{b}$ is perpendicular to $\vec{c},$ then the value of $\vec{a}+ \vec{b}- \vec{c}$ is $…$
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Q60 mcq
If $a+x=b+y=c+z+ 1,$ where $a, \,b, \,c, \,x, \,y, \,z$ are non-zero distinct real numbers, then $x a+y x+a$ $y b+y y+b$ is equal to : $z c+y z+c$
a.
$y(b\,-\,a)$
b.
$y\,(a\,-\,b)$
c.
$0$
d.
$y(a\,-\,c)$
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Q61 mcq
If the mean and the standard deviation of the data $3, 5, 7, \,a, \,b$ are $5$ and $2$ respectively, then $a$ and $b$ are the roots of the equation:
a.
$x^{2} -10x+ 18 = 0$
b.
$2x^{2} -20x+ 19 = 0$
c.
$x^{2} -10x+ 19 = 0$
d.
$x^{2} -20x+ 18 = 0$
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Q62 mcq
The derivative of $tan^{-1}(\frac{\sqrt{1+x^{2}}-1}{x} )$ with respect to $tan^{-1}( \frac{2x\sqrt{1-x^{2}}}{1-2x^{2}})$ at $x= \frac{1}{2}$ is :
a.
$\frac{2\sqrt{3}}{5}$
b.
$\frac{\sqrt{3}}{12}$
c.
$\frac{2\sqrt{3}}{3}$
d.
$\frac{\sqrt{3}}{10}$
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Q63 mcq
If the sum of the first $20$ terms of the series $log_{(7^{1/2})}x+ log_{(7^{1/3})}x+ log_{(7^{1/4})}x+ …$ is $460$ , then $x$ is equal to:
a.
$7^{2}$
b.
$7^{1/2}$
c.
$e^{2}$
d.
$7^{46/21}$
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Q64 mcq
$x(e^{(\sqrt{1+x2+x4}-1)/x}-1)$ $_{x}lim_{\rightarrow 0\rightarrow }_{\sqrt{1+x^{2}+x^{4}}-1}$
a.
is equal to $\sqrt{e}$
b.
is equal to $1$
c.
is equal to $0$
d.
does not exist
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Q65 mcq
If for some, $\alpha \in R,$ the lines $L_{1}: \frac{x+1}{2} = \frac{y-2}{-1} = \frac{z-1}{1}$ and $L_{2}: \frac{x+2}{\alpha} = \frac{y+1}{5-\alpha} = \frac{z+1}{1}$ are coplanar, then the line $L_{2}$ passes through the point :
a.
$(10, \,2, \,2)$
b.
$(2, \,-10, \,-2)\,$
c.
$\,(10, \,-2, \,-2)$
d.
$\,(-2, \,10, \,2)$
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Q66 nat
If the lines $x+y=a$ and $x- y=b$ touch the curve $y=x^{2} -3x+ 2$ at the points where the curve intersects the $x-$ axis, then $\frac{a}{b}$ is equal to $…$
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Q67 mcq
If the system of linear equations $x+y+ 3z= 0$ $x+ 3y+k^{2}z= 0$ $3x+y+ 3z= 0$ has a non-zero solution $(x, \,y, \,z)$ for some $k \in R,$ then $x +(\frac{y}{z} )$ is equal to :
a.
$-3$
b.
$9$
c.
$3$
d.
$-9$
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Q68 mcq
If $x= 1$ is a critical point of the function $f(x)=(3x^{2} +ax-2 - a)e^{x},$ then
a.
$x= 1$ and $x= - \frac{2}{3}$ are local minima of $f$
b.
$x= 1$ and $x= - \frac{2}{3}$ is a local maxima of $f$
c.
$x= 1$ is a local maxima and $x= -\frac{2}{2}$ is a local minima of $f$
d.
$x= 1$ is a local minima and $x= - \frac{2}{3}$ are local maxima of $f$
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Q69 mcq
Let $y=y(x)$ be the solution of the differential equation $cosx\frac{dy}{dx} + 2ysinx= sin 2x,x\in (0, \frac{\pi}{2})$ If $y(\pi /3) = 0,$ then $y(\pi /4)$ is equal to :
a.
$2 - \sqrt{2}$
b.
$2 + \sqrt{2}$
c.
$\sqrt{2}-2$
d.
$\frac{1}{\sqrt{2}} -1$
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Q70 nat
The coefficient of $x^{4}$ in the expansion of $(1 +x+x^{2} +x^{3})^{6}$ in powers of $x,$ is $… . .$
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Q71 mcq
If the length of the chord of the circle, $x^{2} +y^{2} =r^{2}(r> 0)$ along the line, $y-2x= 3$ is $r$ , then $r^{2}$ is equal to:
a.
$\frac{9}{5}$
b.
$12$
c.
$\frac{24}{5}$
d.
$\frac{12}{5}$
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Q72 mcq
The statement $(p (q\rightarrow \rightarrow p)) \rightarrow (\rightarrow p\rightarrow (\rightarrow p\vee q))$ is :
a.
equivalent to $(\vec{p}\wedge q) \vee (~q)$
b.
a contradiction
c.
equivalent to $(p\vee q) \wedge (~p)$
d.
a tautology
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Q73 mcq
There are $3$ sections in a question paper and each section contains $5$ questions. A candidate has to answer a total of $5$ questions, choosing at least one question from each section. Then the number of ways, in which the candidate can choose the questions, is:
a.
$3000$
b.
$1500$
c.
$2255$
d.
$2250$
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Q74 mcq
If the line $y=m x+c$ is a common tangent to the hyperbola $\frac{x^{2}}{100} - \frac{y^{2}}{64} = 1$ and the circle $x^{2} +y^{2} = 36,$ then which one of the following is true?
a.
$c^{2} = 369$
b.
$5m= 4$
c.
$4c^{2} = 369$
d.
$8m+ 5 = 0$
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Q75 mcq
If $\int \frac{cos\theta}{5+7 sin\theta -2 cos^{2}\theta}d\theta =Alog_{e} B(\theta ) +C,$ where $C$ is a constant of integration, then $\frac{B(\theta )}{A}$ can be:
a.
$\frac{2 sin\theta +1}{sin\theta +3}$
b.
$\frac{2 sin\theta +1}{5(sin\theta +3)}$
c.
$\frac{5(sin\theta +3)}{2 sin\theta +1}$
d.
$\frac{5(2 sin\theta +1)}{sin\theta +3}$
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