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JEE Main 2012 (12 May Online)

2012 · 90 questions · First 10 Solutions Free
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Q1 mcq
A solid sphere is rolling on a surface as shown in figure, with a translational velocity $v\,m\,s^{-1}$ . If it is to climb the inclined surface continuing to roll without slipping, then minimum velocity for this to happen is
Question 1 image
a.
$\sqrt{2gh}$
b.
$\sqrt{\frac{7}{5}}gh$
c.
$\sqrt{\frac{7}{2}} gh$
d.
$\sqrt{\frac{10}{7}}gh$ Correct Answer

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Q2 mcq
This question has Statement 1 and Statement 2. Of the four choices given after the Statements, choose the one that best describes the two Statements. Statement 1: A pure semiconductor has negative temperature coefficient of resistance. Statement 2: On raising the temperature, more charge carriers are released into the conduction band.
a.
Statement 1 is false, Statement 2 is true.
b.
Statement 1 is true, Statement 2 is false.
c.
Statement 1 is true, Statement 2 is true, Statement 2 is not a correct explanation of Statement 1.
d.
Statement 1 is true, Statement 2 is true, Statement 2 is the correct explanation of Statement 1. Correct Answer

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Q3 mcq
A wave represented by the equation $y_{1} =acos (kx- \omega t)$ is superimposed with another wave to form a stationary wave such that the point $x-0$ is node. The equation for the other wave is
a.
$acos(kx- \omega t+\pi )$
b.
$acos(kx+\omega t+\pi )$ Correct Answer
c.
$acos(kx+\omega t+ \frac{\pi}{2})$
d.
$acos(kx- \omega t+ \frac{\pi}{2})$

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Q4 mcq
The maximum number of possible interference maxima for slit separation equal to $1.8\lambda$ , where $\lambda$ is the wavelength of light used, in a Young's double slit experiment is
a.
zero
b.
3 Correct Answer
c.
infinite
d.
5

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Q5 mcq
This question has Statement 1 and Statement 2 . Of the four choices given after the Statements, choose the one that best describes the two Statements. Statement 1: Bats emitting ultrasonic waves can detect the location of a prey by hearing the waves reflected from it. Statement 2: When the source and the detector are moving, the frequency of reflected waves is changed.
a.
Statement 1 is false, Statement 2 is true.
b.
Statement 1 is true, Statement 2 is false.
c.
Statement 1 is true, Statement 2 is true, Statement 2 is not the correct explanation of Statement 1. Correct Answer
d.
Statement 1 is true, Statement 2 is true, Statement 2 is the correct explanation of Statement 1.

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Q6 mcq
A student measured the diameter of a wire using a screw gauge with the least count $0.001\,cm$ and listed the measurements. The measured value should be recorded as
a.
$5.3200\,cm$
b.
$5.3\,cm$
c.
$5.32\,cm$
d.
$5.320\,cm$ Correct Answer

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Q7 mcq
Assuming the earth to be a sphere of uniform density, the acceleration due to gravity inside the earth at a distance of $r$ from the centre is proportional to
a.
$r$ Correct Answer
b.
$r^{-1}$
c.
$r^{2}$
d.
$r^{-2}$

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Q8 mcq
This question has Statement 1 and Statement 2. Of the four choices given after the Statements, choose the one that best describes the two Statements. Statement 1: When moment of inertia $I$ of a body rotating about an axis with angular speed $\omega$ increases, its angular momentum $L$ is unchanged but the kinetic energy $K$ increases if there is no torque applied on it. Statement 2: $L=I\omega$ , kinetic energy of rotation $= \frac{1}{2}I\omega ^{2}$
a.
Statement 1 is true, Statement 2 is true, Statement 2 is not the correct explanation of Statement 1.
b.
Statement 1 is false, Statement 2 is true. Correct Answer
c.
Statement 1 is true, Statement 2 is true, Statement 2 is correct explanation of the Statement 1.
d.
Statement 1 is true, Statement 2 is false.

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Q9 mcq
Three resistors of $4\Omega , 6\Omega$ and $12\Omega$ are connected in parallel and the combination is connected in series with a $1.5\,V$ battery of $1\Omega$ internal resistance. The rate of Joule heating in the $4\Omega$ resistor is
a.
$0.55\,W$
b.
$0.33\,W$
c.
$0.25\,W$ Correct Answer
d.
$0.86\,W$

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Q10 mcq
It is preferable to measure the e.m.f. of a cell by potentiometer than by a voltmeter because of the following possible reasons. (i) In case of potentiometer, no current flows through the cell. (ii) The length of the potentiometer allows greater precision. (iii) Measurement by the potentiometer is quicker. (iv) The sensitivity of the galvanometer, when using a potentiometer is not relevant. Which of these reasons are correct?
a.
(i),(iii),(iv)
b.
(i),(iii),(iv)
c.
(i),(ii) Correct Answer
d.
(i),(ii),(iii),(iv)

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Q11 mcq
A spring is compressed between two blocks of masses $m_{1}$ and $m_{2}$ placed on a horizontal frictionless surface as shown in the figure. When the blocks are released, they have initial velocity of $v_{1}$ and $v_{2}$ as shown. The blocks travel distances $x_{1}$ and $x_{2}$ respectively before coming to rest. The ratio $(\frac{x_{1}}{x_{2}})$ is
Question 11 image
a.
$\frac{m_{2}}{m_{1}}$
b.
$\frac{m_{1}}{m_{2}}$
c.
$\sqrt{\,} \frac{m}{m_{1}}^{2}$
d.
$\sqrt{\,} \frac{m}{m_{2}}^{1}$
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Q12 mcq
An insect crawls up a hemispherical surface very slowly. The coefficient of friction between the insect and the surface is $1/3$ . If the line joining the centre of the hemispherical surface to the insect makes an angle $\alpha$ with the vertical, the maximum possible value of $\alpha$ so that the insect does not slip is given by
Question 12 image
a.
$cot\alpha = 3$
b.
$sec\alpha = 3$
c.
$cosec\alpha = 3$
d.
$cos\alpha = 3$
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Q13 mcq
A resistance $R$ and a capacitance $C$ are connected in series to a battery of negligible internal resistance through a key. The key is closed at $t=$ 0 . If after $t$ sec the voltage across the capacitance was seven times the voltage across $R$ , the value of $t$ is
a.
$3RC\ell n2$
b.
$2RC\ell n2$
c.
$2RCln 7$
d.
$3RC\ell n7$
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Q14 mcq
Which of the following Statements is correct?
a.
The rate of radioactive decay cannot be controlled but that of nuclear fission can be controlled.
b.
Nuclear forces are short range, attractive and charge dependent.
c.
Nuclei of atoms having same number of neutrons are known as isobars.
d.
Wavelength of matter waves is given by de Broglie formula but that of photons is not given by the same formula
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Q15 mcq
The distance travelled by a body moving along a line in time $t$ is proportional to $t^{3}$ . The acceleration-time $(a,t)$ graph for the motion of the body will be
Question 15 image
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Q16 mcq
A hypothetical atom has only three energy levels. The ground level has energy, $E_{1} = -8eV$ . The two excited states have energies, $E_{2} = -6eV$ and $E_{3} = -2eV$ . Then which of the following wavelengths will not be present in the emission spectrum of this atom?
a.
$207\,nm$
b.
$465\,nm$
c.
$310\,nm$
d.
$620\,nm$
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Q17 mcq
A given ideal gas with $\gamma = \frac{C_{p}}{C_{v}} = 1.5$ at a temperature $T$ . If the gas is compressed adiabatically to one-fourth of its initial volume, the final temperature will be
a.
$2\sqrt{2}T$
b.
$4T$
c.
$2T$
d.
$8T$
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Q18 mcq
A $10\,kW$ transmitter emits radio waves of wavelength $500\,m$ . The number of photons emitted per second by the transmitter is of the order of
a.
$10^{37}$
b.
$10^{31}$
c.
$10^{25}$
d.
$10^{43}$
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Q19 mcq
A doubly ionised $Li$ atom is excited from its ground $state(n= 1)$ to $n= 3$ state. The wavelengths of the spectral lines are given by $\lambda _{32},\lambda _{31}$ and $\lambda _{21}$ . The ratio $\lambda _{32}/\lambda _{31}$ and $\lambda _{21}/\lambda _{31}$ are, respectively
a.
$8.1, 0.67$
b.
$8.1, 1.2$
c.
$6.4, 1.2$
d.
$6.4, 0.67$
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Q20 mcq
Magnetic flux through a coil of resistance $10\Omega$ is changed by $\Delta \phi$ in $0.1\,s$ . The resulting current in the coil varies with time as shown in the figure. Then $|\Delta \phi |$ is equal to (in weber)
Question 20 image
a.
6
b.
4
c.
2
d.
8
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Q21 mcq
In a sensitive meter bridge apparatus the bridge wire should possess
a.
high resistivity and low temperature coefficient.
b.
low resistivity and high temperature coefficient.
c.
low resistivity and low temperature coefficient.
d.
high resistivity and high temperature coefficient.
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Q22 mcq
The circuit in figure consists of wires at the top and bottom and identical springs as the left and right sides. The wire at the bottom has a mass of $10\,g$ and is $5\,cm$ long. The wire is hanging as shown in the figure. The springs stretch $0.5\,cm$ under the weight of the wire and the circuit has a total resistance of $12\Omega$ . When the lower wire is subjected to a static magnetic field, the springs, stretch an additional $0.3\,cm$ . The magnetic field is
Question 22 image
a.
$0.6\,T$ and directed out of page
b.
$1.2\,T$ and directed into the plane of page
c.
$0.6\,T$ and directed into the plane of page
d.
$1.2\,T$ and directed out of page
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Q23 mcq
A projectile moving vertically upwards with a velocity of $200\,ms^{-1}$ breaks into two equal parts at a height of $490\,m$ . One part starts moving vertically upwards with a velocity of $400\,ms^{-1}$ . How much time it will take, after the break up with the other part to hit the ground?
a.
$2\,s\sqrt{10}$
b.
$5\,s$
c.
$10\,s$
d.
$\sqrt{10}\,s$
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Q24 mcq
The magnetic force acting on charged particle of charge $2\mu C$ in magnetic field of $2T$ acting in $y-$ direction, when the particle velocity is $(2\hat{i}+ 3\hat{j}) \times 10^{6}\,ms^{-1}$ is
a.
$8\,N$ in z-direction
b.
$8\,N$ in y-direction
c.
$4\,N$ in y-direction
d.
$4\,N$ in z-direction
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Q25 mcq
Two bodies $A$ and $B$ of mass $m$ and $2m$ respectively are placed on a smooth floor. They are connected by a spring of negligible mass. $A$ third body $C$ of mass $m$ is placed on the floor. The body $C$ moves with a velocity $v_{0}$ along the line joining $A$ and $B$ and collides elastically with $A$ . At a certain time after the collision it is found that the instantaneous velocities of $A$ and $B$ are same and the compression of the spring is $x_{0}$ . The spring constant $k$ will be
a.
$m\frac{v^{2}_{0}}{x^{2}_{0}}$
b.
$m\frac{v_{0}}{2x_{0}}$
c.
$2m \frac{v_{0}}{x_{0}}$
d.
$2$ $\frac{2}{3} m(\frac{v_{0}}{x_{0}})$
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Q26 mcq
The first diffraction minimum due to the single slit diffraction is seen at $\theta = 30^{\circ }$ for a light of wavelength $5000$ Åfalling perpendicularly on the slit. The width of the slit is
a.
$2.5 \times 10^{-5}\,cm$
b.
$1.25 \times 10^{-5}\,cm$
c.
$10 \times 10^{-5}\,cm$
d.
$5 \times 10^{-5}\,cm$
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Q27 mcq
Water is flowing through a horizontal tube having cross-sectional areas of its two ends being $A$ and $A'$ such that the ratio $A/A'$ is 5 . If the pressure difference of water between the two ends is $3\times 10^{5}\,N\,m^{-2}$ , the velocity of water with which it enters the tube will be (neglect gravity effects)
a.
$5\,m\,s^{-1}$
b.
$10\,m\,s^{-1}$
c.
$25\,m\,s^{-1}$
d.
$50\,m\,s\sqrt{10}^{-1}$
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Q28 mcq
$n$ moles of an ideal gas undergo a process $A\rightarrow \rightarrow B$ as shown in the figure. Maximum temperature of the gas during the process is
Question 28 image
a.
$\frac{9P_{0}V_{0}}{nR}$
b.
$\frac{3P_{0}V_{0}}{2nR}$
c.
$\frac{9P_{0}V_{0}}{2nR}$
d.
$\frac{9P_{0}V_{0}}{4nR}$
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Q29 mcq
We wish to make a microscope with the help of two positive lenses both with a focal length of 20 $mm$ each and the object is positioned $25\,mm$ from the objective lens. How far apart the lenses should be so that the final image is formed at infinity?
a.
$20\,mm$
b.
$100\,mm$
c.
$120\,mm$
d.
$80\,mm$
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Q30 mcq
A series combination of $n_{1}$ capacitors, each of capacity $C_{1}$ is charged by source of potential difference $4\,V$ . When another parallel combination of $n_{2}$ capacitors each of capacity $C_{2}$ is charged by a source of potential difference $V$ , it has the same total energy stored in it as the first combination has. The value of $C_{2}$ in terms of $C_{1}$ is then
a.
$16\frac{n_{2}}{n_{1}} C_{1}$
b.
$\frac{2C_{1}}{n_{1}n_{2}}$
c.
$2\frac{n_{2}}{n_{1}}C_{1}$
d.
$\frac{16C_{1}}{n_{1}n_{2}}$
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Q31 mcq
In the below mentioned compounds the decreasing order of reactivity towards electrophilic substitution is (i) (ii) (iii) (iv)
Question 31 image
a.
(iv) $>$ (i) $>$ (ii) $>$ (iii)
b.
(ii) $>$ (iii) $>$ (i) $>$ (iv)
c.
(iii) $>$ (i) $>$ (iv) $>$ (ii)
d.
(i) $>$ (ii) $>$ (iii) $>$ (iv)
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Q32 mcq
A metal $M$ on heating in nitrogen gas gives $Y$ . $Y$ on treatment with $H_{2}O$ gives a colourless gas which when passed through $CuSO_{4}$ solution gives a blue colour. $Y$ is
a.
$NH_{3}$
b.
$Mg(NO_{3})_{2}$
c.
$Mg_{3}\,N_{2}$
d.
$MgO$
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Q33 mcq
The conversion of benzene diazonium chloride to bromobenzene can be accomplished by
a.
Reimer-Tiemann reaction
b.
Friedel-Crafts reaction
c.
Gattermann reaction
d.
Azo-coupling reaction
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Q34 mcq
The radius of a calcium ion is $94pm$ and of the oxide ion is $146pm$ . The possible crystal structure of calcium oxide will be
a.
tetrahedral
b.
trigonal
c.
octahedral
d.
pyramidal
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Q35 mcq
In the electrolysis of alumina to obtain aluminium metal, cryolite is added mainly to
a.
lower the melting point of alumina
b.
dissolve alumina in molten cryolite
c.
remove the impurities of alumina
d.
increase the electrical conductivity
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Q36 mcq
Which of the following statements is wrong?
a.
Ethyl chloride on reduction with $Zn -Cu$ couple and alcohol gives ethane.
b.
The reaction of methyl magnesium bromide with acetone gives butanol-2.
c.
Alkyl halides follow the following reactivity sequence on reaction with alkenes. $R -I > R -Br > R -Cl > R -I$
d.
$C_{2}H_{4}Cl_{2}$ may exist in two isomeric forms
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Q37 mcq
Magnetic moment of $Gd^{3+}$ ion $(Z = 64)$ is
a.
3.62 BM
b.
$9.72BM$
c.
7.9 BM
d.
$10.60BM$
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Q38 mcq
In a chemical reaction $A$ is converted into $B$ . The rates of reaction, starting with initial concentrations of $A$ as $2 \times 10^{-3}M$ and $1 \times 10^{-3} M$ , are equal to $2.40 \times 10^{-4}Ms^{-1}$ and $0.60 \times 10^{-4}Ms^{-1}$ respectively. The order of reaction with respect to reactant $A$ will be
a.
0
b.
$1.5$
c.
1
d.
2
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Q39 mcq
Among the following chloro-compound having the lowest dipole moment is
Question 39 image
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Q40 mcq
An aqueous solution of oxalic acid dihydrate contains its $6.3\,g$ in $250ml$ . The volume of $0.1\,N NaOH$ required to completely neutralize $10ml$ of this solution
a.
$4ml$
b.
$20ml$
c.
$2ml$
d.
$40ml$
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Q41 mcq
Given (i) $HCN(aq) + H_{2}O(b)\rightleftharpoons H_{3}O^{+}(aq) + CN^{-}(aq)K_{a} = 6.2 \times 10^{-10}$ (ii) $CN^{-}(aq) + H_{2}O(l)\rightleftharpoons HCN(aq) + OH^{-}(aq)K_{b} = 1.6 \times 10^{-5}$ . These equilibria show the following order of the relative base strength,
a.
$OH^{-} > H_{2}O > CN^{-}$
b.
$OH^{-} > CN^{-} > H_{2}O$
c.
$H_{2}O > CN^{-} > OH$
d.
$CN^{-} > H_{2}O > OH^{-}$
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Q42 mcq
$\alpha ,v$ and $u$ represent most probable velocity, average velocity and root mean square velocity respectively of a gas at a particular temperature. The correct order among the following is
a.
$u>v>\alpha$
b.
$v>u>\alpha$
c.
$\alpha >u>v$
d.
$u>\alpha >v$
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Q43 mcq
The correct statement for both the processes of physisorption and chemisorption is
a.
both are endothermic
b.
chemisorption is endothermic but physisorption is exothermic
c.
both are exothermic
d.
physisorption is endothermic but chemisorption is exothermic.
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Q44 mcq
In the following balanced reaction, values of $X,Y$ and $Z$ respectively are
a.
2,5,16
b.
$8, 2, 5$
c.
$5, 2, 16$
d.
$5, 8, 4$
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Q45 mcq
The reaction, $CH_{3}CHO\frac{[H]}{Zn(Hg)/\,Conc.\,HCl}CH_{3}CH_{3}$
a.
Cannizaro's reaction
b.
Rosenmund reduction
c.
Wolf-Kishner reduction
d.
Clemmenson reduction
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Q46 mcq
Which among the following elements has the highest first ionization enthalpy?
a.
Nitrogen
b.
Boron
c.
Carbon
d.
Oxygen
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Q47 mcq
The difference between the reaction enthalpy change $(\Delta _{r}H)$ and reaction internal energy change $(\Delta _{r}U)$ for the reaction: $2C_{6}H_{6}(l) + 15O_{2}(\,g)\longrightarrow$ at $300\,K$ is $(R = 8.314\,J\,mol^{-1}\,K^{-1})$
a.
$0\,J\,mol^{-1}$
b.
$2490\,J\,mol^{-1}$
c.
$-2490\,J\,mol^{-1}$
d.
$-7482\,J\,mol^{-1}$
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Q48 mcq
Which of the following complex ions will exhibit optical isomerism? (en = 1, 2-diamine ethane).
a.
$[Cr(NH_{3})_{2}Cl_{2}]^{+}$
b.
$[Co(en)_{2}Cl_{2}]^{+}$
c.
$[Co(NH_{3})_{4}Cl_{2}]^{+}$
d.
$[Zn(en)_{2}]^{2+}$
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Q49 mcq
If the radius of first orbit of $H$ atom is $a_{0}$ , the deBroglie wavelength of an electron in the third orbit is
a.
$4\pi a_{0}$
b.
$8\pi a_{0}$
c.
$6\pi a_{0}$
d.
$2\pi a_{0}$
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Q50 mcq
The formation of molecular complex $BF_{3}-NH_{3}$ results in a change in hybridization of boron
a.
from $sp^{2}$ to $dsp^{2}$
b.
from $sp^{2}$ to $sp^{3}$
c.
from $sp^{3}$ to $sp^{2}$
d.
from $sp^{3}$ to $sp^{3}d$
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Q51 mcq
$8\,mol$ of $AB_{3}(\,g)$ are introduced into a $1.0dm^{3}$ vessel. If it dissociates as $2AB_{3}(g)\rightleftharpoons A_{2}(g) + 3B_{2}(g)$ . At equilibrium, $2\,mol$ of $A_{2}$ are found to be present. The equilibrium constant of this reaction is
a.
2
b.
3
c.
27
d.
36
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Q52 mcq
Chemically heroin is
a.
morphine monoacetate
b.
morphine dibenzoate
c.
morphine diacetate
d.
morphine monobenzoate
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Q53 mcq
A solution containing $0.85\,g$ of $ZnCl_{2}$ in $125.0\,g$ of water freezes at $-0.23^{\circ }C$ . The apparent degree of dissociation of the salt is $(K_{f}$ for water $= 1.86\,K\,kg\,mol^{-1}$ , atomic mass: $Zn = 65.3$ and $Cl = 35.5)$
a.
$1.36%$
b.
$73.5%$
c.
$7.35%$
d.
$2.47%$
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Q54 mcq
The ppm level of $F^{-}$ in a $500\,g$ sample of a tooth paste containing $0.2\,g\,F^{-}$ is
a.
400
b.
1000
c.
250
d.
200
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Q55 mcq
Water sample is reported to be highly polluted if BOD (Biological Oxygen Demand) value of sample becomes
a.
more than $17ppm$
b.
equal to $10ppm$
c.
equal to $5ppm$
d.
less than $5ppm$
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Q56 mcq
Although $CN^{-}$ ion and $N_{2}$ molecule are isoelectronic, yet $N_{2}$ molecule is chemically inert because of
a.
presence of more number of electrons in bonding orbitals
b.
lone bond energy
c.
absence of bond polarity
d.
uneven electron distribution.
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Q57 mcq
Amylopectin is a polymer of
a.
$\alpha - D-$ glucose
b.
amino acid
c.
$\beta - D-$ glucose
d.
amylase.
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Q58 mcq
$5\,g$ of benzene on nitration gave $6.6\,g$ of nitrobenzene. The theoretical yield of the nitrobenzene will be
a.
$4.5\,g$
b.
$5.6\,g$
c.
$8.09\,g$
d.
$6.6\,g$
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Q59 mcq
In the given reaction, the product 'A' is
Question 59 image
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Q60 mcq
Synthetic polymer bakelite can be prepared from following compounds
a.
Styrene and vinyl chloride
b.
Acrylonitrile and vinyl chloride
c.
Adipic acid and ethylene glycol
d.
Phenol and formaldehyde
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Q61 mcq
Statement 1: If $A$ and $B$ be two sets having $p$ and $q$ elements respectively, where $q>p$ . Then the total number of functions from set $A$ to set $B$ is $q^{p}$ Statement 2: The total number of selections of $p$ different objects out of $q$ objects is $^{q}C_{p}$ .
a.
Statement 1 is true, Statement 2 is false.
b.
Statement 1 is true, Statement 2 is true, Statement 2 is not a correct explanation of Statement 1.
c.
Statement 1 is false, Statement 2 is true
d.
Statement 1 is true, Statement 2 is true, Statement 2 is a correct explanation of Statement 1.
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Q62 mcq
If the sum of the square of the roots of the equation $x^{2} -(sin\alpha -2)x-(1 + sin\alpha ) = 0$ is least, then $\alpha$ is equal to
a.
$\frac{\pi}{6}$
b.
$\frac{\pi}{4}$
c.
$\frac{\pi}{3}$
d.
$\frac{\pi}{2}$
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Q63 mcq
Statement 1: The degrees of the differential equations $\frac{dy}{dx} +y^{2} =x$ and $\frac{d^{2}y}{dx^{2}} +y= sinx$ are equal. Statement 2: The degree of a differential equation, when it is a polynomial equation in derivatives, is the highest positive integral power of the highest order derivative involved in the differential equation, otherwise degree is not defined.
a.
Statement 1 is true, Statement 2 is true, Statement 2 is not a correct explanation of Statement 1.
b.
Statement 1 is false, Statement 2 is true.
c.
Statement 1 is true, Statement 2 is false.
d.
Statement 1 is true, Statement 2 is true; Statement 2 is a correct explanation of Statement 1.
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Q64 mcq
$| |$ If $f'(x) = sin(logx)$ and $y=f(\frac{2x+3}{3-2x})$ , then $\frac{dy}{dx}$ equals
a.
$sin[log(\frac{2x+3}{3-2x})]$
b.
$\frac{12}{(3-2x^{2})}$
c.
$\frac{12}{(3-2x^{2})}sin[log(\frac{2x+3}{3-2x})]$
d.
$\frac{12}{(3-2x^{2}}cos[log( \frac{2x+3}{3-2x})]$
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Q65 mcq
If $P_{1}$ and $P_{2}$ are two points on the ellipse $\frac{x^{2}}{4} +y^{2} = 1$ at which the tangents are parallel to the chord joining the points $(0, 1)$ and $(2, 0)$ , then the distance between $P_{1}$ and $P_{2}$ is
a.
$2\sqrt{2}$
b.
$\sqrt{5}$
c.
$2\sqrt{3}$
d.
$\sqrt{10}$
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Q66 mcq
A unit vector which is perpendicular to the vector $2\hat{i}- \hat{j}+ 2\hat{k}$ and is coplanar with the vectors $\hat{i}+ \hat{j}- \hat{k}$ and $2\hat{i}+ 2\hat{j}- \hat{k}$ is
a.
$\frac{2\hat{j}+\hat{k}}{\sqrt{5}}$
b.
$\frac{3\hat{i}+2\hat{j}-2\hat{k}}{\sqrt{17}}$
c.
$\frac{3\hat{i}+2\hat{j}+2\hat{k}}{\sqrt{17}}$
d.
$\frac{2\hat{i}+2\hat{j}-\hat{k}}{3}$
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Q67 mcq
The area of triangle formed by the lines joining the vertex of the parabola, $x^{2} = 8y$ , to the extremities of its latus rectum is
a.
2
b.
8
c.
1
d.
4
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Q68 mcq
A number $n$ is randomly selected from the set ${1, 2, 3, … . , 1000}$ . The probability that $\frac{\sum ^{n}_{i}_{=1}i^{2}}{\sum ^{n}_{i}_{=1}i}$ is an integer is
a.
$0.331$
b.
$0.333$
c.
$0.334$
d.
$0.332$
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Q69 mcq
If in a triangle $ABC, \frac{b+c}{11} = \frac{c+a}{12} = \frac{a+b}{13}$ , then $cos A$ is equal to
a.
$5/7$
b.
$1/5$
c.
$35/19$
d.
$19/35$
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Q70 mcq
If $A= {x\in z^{+} :x< 10$ and $x$ is a multiple of 3 or $4}$ , where $z^{+}$ is the set of positive integers, then the total number of symmetric relations on $A$ is
a.
$2^{5}$
b.
$2^{15}$
c.
$2^{10}$
d.
$2^{20}$
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Q71 mcq
If two vertices of a triangle are $(5, -1)$ and $(-2, 3)$ and its orthocentre is at $(0, 0)$ , then the third vertex is
a.
$(4, -7)$
b.
$(-4, -7)$
c.
$(-4, 7)$
d.
$(4, 7)$
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Q72 mcq
If $\vec{u}= \hat{j}+ 4\hat{k}, \vec{v}= ^\wedge\vec{i}+ 3\hat{k}$ and $\vec{w}= cos\theta \hat{i}+ sin\theta \hat{j}$ are vectors in 3-dimensional space, then the maximum possible value of $|u\times \vec{v}\cdot \vec{w}|$ is
a.
$\sqrt{3}$
b.
5
c.
$\sqrt{14}$
d.
7
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Q73 mcq
$-2a a+b a+c$ If $b+a -2b b+c$ $c+a b+c -2c$ $=\alpha (a+b()b+c()c+a) \neq 0$ then $\alpha$ is equal to
a.
$a+b+c$
b.
$abc$
c.
4
d.
1
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Q74 mcq
If $a,b,c,d$ and $p$ are distinct real numbers such that $(a^{2} +b^{2} +c^{2})p^{2} -2p(ab+bc+cd) +(b^{2}+$ $c^{2} +d^{2})\leq 0$ , then
a.
$a,b,c,d$ are in A.P.
b.
$ab=cd$
c.
$ac=bd$
d.
$a,b,c,d$ are in G.P.
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Q75 mcq
If $\frac{d}{dx}G(x) = \frac{e^{tan}^{x}}{x},x\in (0,\pi /2)$ , then $\int _{1/4}^{1/2} \frac{2}{x} \cdot e^{tan(\pi x^{2})}dx$ is equal to
a.
$G(\pi /4) - G(\pi /16)$
b.
$2[G(\pi /4) - G(\pi /16)]$
c.
$\pi [G(1/2) - G(1/4)]$
d.
$G(1/\sqrt{2}) - G(1/2)$
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Q76 mcq
If $f(x) =xe^{x(1-x)},x\in R$ , then $f(x)$ is
a.
decreasing on $[-1/2, 1]$
b.
decreasing on $R$
c.
increasing on $[-1/2, 1]$
d.
increasing on $R$
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Q77 mcq
The logically equivalent preposition of $p\Leftrightarrow q$ is
a.
$(p\Rightarrow q\wedge )q\Rightarrow p )$
b.
$p\wedge q$
c.
$(p\wedge q\vee )q\neq p )$
d.
$(p\wedge q\Rightarrow q\vee (p )$
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Q78 mcq
$||$ $||$ Statement 1: If the points $(1, 2, 2), (2, 1, 2)$ and $(2, 2,z)$ and $(1, 1, 1)$ are coplanar, then $z= 2$ . Statement 2: If the 4 points $P,Q,R$ and $S$ are coplanar, then the volume of the tetrahedron $PQRS$ is 0.
a.
Statement 1 is false,, Statement 2 is true.
b.
Statement 1 is true, Statement 2 is false.
c.
Statement 1 is true, Statement 2 is true, Statement 2 is a correct explanation of Statement 1.
d.
Statement 1 is true, Statement 2 is true, Statement 2 is not a correct explanation of Statement 1.
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Q79 mcq
If the mean of $4, 7, 2, 8, 6$ and a is 7 , then the mean deviation from the median of these observations is
a.
8
b.
5
c.
1
d.
3
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Q80 mcq
If a straight line $y- x= 2$ divides the region $x^{2} +y^{2} \leq 4$ into two parts, then the ratio of the area of the smaller part to the area of the greater part is
a.
$3\pi -8 :\pi + 8$
b.
$\pi -3 : 3\pi + 3$
c.
$3\pi -4 :\pi + 4$
d.
$\pi -2 : 3\pi + 2$
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Q81 mcq
The number of terms in the expansion of $(y^{1/5} +x^{1/10})^{55}$ , in which powers of $x$ and $y$ are free from radical signs are
a.
$six$
b.
twelve
c.
seven
d.
five
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Q82 mcq
The integral of $\frac{x^{2}-x}{x^{3}-x^{2}+x-1}$ w.r.t. $x$ is
a.
$\frac{1}{2}log(x^{2}+ 1 +c)$
b.
$\frac{1}{2}log x^{2}-1 +c$
c.
$log(x^{2} + 1 +c)$
d.
$log x^{2} -1 +c$
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Q83 mcq
The area enclosed by the curves $y=x^{2},y=x^{3}$ , $x= 0$ and $x=p$ , where $p> 1$ , is $1/6$ . The $p$ equals
a.
$8/3$
b.
$16/3$
c.
2
d.
$4/3$
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Q84 mcq
Consider a rectangle whose length is increasing at the uniform rate of $2\,m/sec$ , breadth is decreasing at the uniform rate of $3\,m/sec$ and the area is decreasing at the uniform rate of $5\,m^{2}/sec$ . If after some time the breadth of the rectangle is $2\,m$ then the length of the rectangle is
a.
$2\,m$
b.
$4\,m$
c.
$1\,m$
d.
$3\,m$
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Q85 mcq
The area of the triangle whose vertices are complex numbers $z,iz,z+iz$ in the Argand diagram is
a.
$2|z|^{2}$
b.
$1/2|z|^{2}$
c.
$4|z|^{2}$
d.
$|z|^{2}$
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Q86 mcq
If the point $(1,a)$ lies between the straight lines $x+y= 1$ and $2(x+y) = 3$ then a lies in interval
a.
$(\frac{3}{2} , \infty )$
b.
$(1, \frac{3}{2})$
c.
$(-\infty , 0)$
d.
$(0, \frac{1}{2})$
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Q87 mcq
The sum of the series $1 1 1$ $+ + + …$ $1 + \sqrt{2} \sqrt{2}+ \sqrt{3} \sqrt{3}+ \sqrt{4}$ upto 15 terms is
a.
1
b.
2
c.
3
d.
4
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Q88 mcq
The coordinates of the foot perpendicular from the point $(1, 0, 0)$ to the line $\frac{x-1}{2} = \frac{y+ 1}{-3} = \frac{z+ 10}{8} \,are\,$
a.
$(2, -3, 8)$
b.
$(1, -1, -10)$
c.
$(5, -8, -4)$
d.
$(3, -4, -2)$
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Q89 mcq
$\alpha 0 0 \gamma$ Let $A$ and $B$ be real matrices of the form $[ ]$ and $[ ]$ , respectively. Statement 1: $AB- BA$ is always $0 \beta \delta 0$ an invertible matrix. Statement $2 :AB- BA$ is never an identity matrix.
a.
Statement 1 is true, Statement 2 is false.
b.
Statement 1 is false, Statement 2 is true.
c.
Statement 1 is true, Statement 2 is true; Statement 2 is a correct explanation of Statement 1 .
d.
Statement 1 is true, Statement 2 is true, Statement 2 is not a correct explanation of Statement 1.
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Q90 mcq
Statement 1: A function $f :R\rightarrow \rightarrow R$ is continuous at $x_{0}$ if and only if $lim_{x\rightarrow \rightarrow x_{0}}f(x)$ exists and $lim_{x\rightarrow \rightarrow x_{0}}f(x) =f(x_{0}\cdot )$ Statement 2: A function $f :R\rightarrow \rightarrow R$ is discontinuous at $x_{0}$ if and only if, $lim_{x\rightarrow \rightarrow x_{0}}f(x)$ exists and $lim_{x\rightarrow \rightarrow x_{0}}f(x) \neq f(x_{0}. )$
a.
Statement 1 is true, Statement 2 is true, Statement 2 is not a correct explanation of Statement 1.
b.
Statement 1 is false, Statement 2 is true.
c.
Statement 1 is true, Statement 2 is true, Statement 2 is a correct explanation of Statement 1.
d.
Statement 1 is true, Statement 2 is false.
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