question_answer4) The value of \[{{\tan }^{-1}}\left[ \frac{\sqrt{1+{{x}^{2}}}+\sqrt{1-{{x}^{2}}}}{\sqrt{1+{{x}^{2}}}-\sqrt{1-{{x}^{2}}}} \right],|x|<\frac{1}{2},x\ne 0,\]is equal to: [JEE Online 08-04-2017]
question_answer5) The area (in sq. units) of the parallelogram whooshed diagonals are along the vectors \[8\hat{i}-6\hat{j}\]and\[3\hat{i}+4\hat{j}-12\hat{k},\]is: [JEE Online 08-04-2017]
question_answer7) Let\[z\in C,\]the set of complex numbers. Then the equation, \[2|z+3i|-|z-i|=0\]a circle with radius\[\frac{8}{3}.\] [JEE Online 08-04-2017]
A)
a circle with radius\[\frac{8}{3}\]
doneclear
B)
an ellipse with length of minor axis\[\frac{16}{9}\]
doneclear
C)
an ellipse with length of major axis\[\frac{16}{3}\]
question_answer8) If the um of the first n terms of the series\[\sqrt{3}+\sqrt{75}+\sqrt{243}+\sqrt{507}+........\]is\[435\sqrt{3},\]then n equals. [JEE Online 08-04-2017]
question_answer12) If all the words, with or without meaning, are written using the letters of the word QUEEN and are arranged as in English dictionary, then the position of the word QUEEN is: [JEE Online 08-04-2017]
question_answer13) The curve satisfying the differential equation, \[ydx-(x+3{{y}^{2}})dy=9\]and passing through the point (1,1), also passes through the point: [JEE Online 08-04-2017]
question_answer14) An unbiased coin is tossed eight times. The probability of obtaining at least one head and at least one tails is: [JEE Online 08-04-2017]
question_answer15) If the arithmetic mean of two numbers and b,a, > b > 0. Is five times their geometric mean, then\[\frac{a+b}{a-b}\]is equal to: [JEE Online 08-04-2017]
question_answer19) The area (in sq. units) of the smaller portion enclosed between the curves, \[{{x}^{2}}+{{y}^{2}}=4\]and\[{{y}^{2}}=3x,\]is: [JEE Online 08-04-2017]
question_answer20) If the common tangents to the parabola \[{{x}^{2}}+4y\]and the circle,\[{{x}^{2}}+{{y}^{2}}=4\]intersect at the point P, then the distance of P from the origin, is: [JEE Online 08-04-2017]
question_answer21) The line of intersection of the planes \[\vec{r}.\left( 3\hat{i}-\hat{j}+\hat{k} \right)=1\]and\[\vec{r}.\left( \hat{i}+4\hat{j}-2\hat{k} \right)=2,\]is: [JEE Online 08-04-2017]
question_answer22) If a point P has co-ordinates (0,-2) and Q is any point on the circle,\[{{x}^{2}}+{{y}^{2}}-5x-y+5=0,\]then the maximum value of\[{{(PQ)}^{2}}\]is: [JEE Online 08-04-2017]
question_answer23) The mean age of 25 teaches in a school is 40 years. A teacher retires at the age of 60 years and a new teacher is appointed in his place. If now the mean age of the teachers in this school is 39 years, then the age (in years) of the newly appointed teachers is: [JEE Online 08-04-2017]
question_answer24) Let p (x) be a quadratic polynomial such that p(0)=1. If p(x) leaves remainder 4 when divided by x-1 and it leaves remainder 6 when divided by x + 1, then: [JEE Online 08-04-2017]
question_answer25) Consider an ellipse, whose centre is at the origin and its major axis is along the x - axis. if its eccentricity is \[\frac{3}{5}\]and the distance between its foci is 6, then the area ( in sq. units ) of the quadrilateral inscribed in the ellipse, with the vertices as the vertices of the ellipse, is : [JEE Online 08-04-2017]
question_answer26) If two parallel chords of the a circle, having diameter 4 units, lie on the opposite sides of the centre and subtend angles \[{{\cos }^{-1}}\left( \frac{1}{7} \right)\]and\[{{\sec }^{-1}}(7)\]at the centre respectively, then the distance between these chords, is : [JEE Online 08-04-2017]
question_answer27) The number of real values of \[\lambda \]for which the system of linear equations \[2x+4y-\lambda z=0\] \[4x+\lambda y+2z=0\] \[\lambda x+2y+2z=0\] has infinitely many solutions, is : [JEE Online 08-04-2017]
question_answer28) The coordinates of the foot of the perpendicular from the point (1, - 2,1) on the plane containing the lines, \[\frac{x+1}{6}=\frac{y-1}{7}=\frac{z-3}{8}\]and \[\frac{x-1}{3}=\frac{y-2}{5}=\frac{z-3}{7},\]is: [JEE Online 08-04-2017]
question_answer29) Three persong P, Q and R independently try to hit a target. If the probabilities of their hitting the target are \[\frac{3}{4},\frac{1}{2}\]and\[\frac{5}{8}\]respectively, then the probability that the target is hit by P or Q but not by R is : [JEE Online 08-04-2017]
question_answer30) The integral\[\int_{{}}^{{}}{\sqrt{1+2\cot x(cosecx+cotx)}dx}\]\[\left( 0<x<\frac{x}{2} \right)\]is equal to : (where C is a constant of integration ) [JEE Online 08-04-2017]
question_answer31) A compressive force, F is applied at the two ends of a long thin steel rod. It is heated, simultaneously, such that its temeprature increases by \[\Delta T.\] The net change in its length is zero. Let l be the length of the rod, A its area of cross-section, Y its Young's modulus, and \[\alpha \] its coefficient of linear expansion. Then, F is equal to - [JEE Online 08-04-2017]
question_answer32) A potentiometer PQ is set up to comapre two resistances as shown in the figure. The ammeter A in the circuit reads 1.0 A when two way key \[{{K}_{3}}\] is open. The balance point is at a length \[{{l}_{1}}\]cm from P when two way key \[{{K}_{3}}\] is plugged in between 2 and 1, while the balance point is at a length \[{{l}_{2}}\] cm from P when key \[{{K}_{3}}\] is plugged in between 3 and 1. The ratio of the two resistance \[\frac{{{R}_{1}}}{{{R}_{2}}},\] is found to be - [JEE Online 08-04-2017]
question_answer33) A signal of frequency 20 kHz and peak voltage of 5 volt is used to modulate a carrier wave of frequency 1.2 MHz and peak voltage 25 volts. Choose the correct statement. [JEE Online 08-04-2017]
A)
Modulation index = 5, side frequency bands are at 1400 kHz and 1000 kHz
doneclear
B)
Modulation index = 0.8, side frequency bands are at 1180 kHz and 1220 kHz
doneclear
C)
Modulation index = 0.2, side frequency bands are at 1200 kHz and 1180 kHz
doneclear
D)
Modulation index = 5, side frequency bands are at 21/2 kHz and 18.8 kHz
question_answer34) A single slit of width b is illuminated by a coherent monochromatic light of wavelength \[\lambda \].If the second and fourth minima in the diffraction pattern at a distance 1 m from the slit are at 3 cm and 6 cm respectively from the central maximum, what is the width of the central maximum ? (i.e., distance between first minimum on either side of the central maximum) [JEE Online 08-04-2017]
question_answer35) A 1 kg block attached to a spring vibrates with a frequency of 1 Hz on a frictionless horizontal table. Two springs identical to the original spring are attached in parallel to an 8 kg block placed on the same table. So, the frequency of vibration of the 8 kg block is - [JEE Online 08-04-2017]
question_answer37) If the earth has no rotational motion, the weight of a person on the equation is W. Detrmine the speed with which the earth would have to rotate about its axis so that the person at the equator will weight\[\frac{3}{4}W.\]Radius of the earth is 6400 km and \[g=10m/{{s}^{2}}.\] [JEE Online 08-04-2017]
question_answer38) An object is dropped from a height h from the ground. Every time it hits the ground it looses 50% of its kinetic energy. The total distance covered as \[t\to \infty \]is - [JEE Online 08-04-2017]
question_answer39) The energy stored in the electric field produced by a metal sphere is 4.5 J. If the sphere contains \[4\mu C\] charge, its radius will be: [Take:\[\frac{1}{4\pi {{\varepsilon }_{0}}}=9\times {{10}^{9}}N-{{m}^{2}}/{{C}^{2}}\]] [JEE Online 08-04-2017]
question_answer40) A uniform disc of radius R and mass M is free to rotate only about its axis. A string is wrapped over its rim and a body of mass m is tied to the free end of the string as shown in the figure. The body is released from rest. Then the acceleration of the body is - [JEE Online 08-04-2017]
question_answer41) An engine operates by taking n moles of an ideal gas through the cycle ABCDA shown in figure. The thermal efficiency of the engine is - (Take \[{{C}_{v}}=1.4R,\]where R is gas constant) [JEE Online 08-04-2017]
question_answer42) Time (T), velocity (3) and angular momentum (h) are chosen as fundamental quantities instead of mass, length and time. In terms of these, the dimensions of mass would be - [JEE Online 08-04-2017]
question_answer43) In an experiment a sphere of aluminium of mass 0.20 kg is heated upto\[{{150}^{o}}C\]. Immediately, it is put into water of volume \[150cc\] at \[{{27}^{o}}C\] kept in a calorimeter of water equivalent to 0.025 kg. Final temperature of the system is\[{{40}^{o}}C\]. The specific heat of aluminium is - (take 4.2 Joule = 1 calorie) [JEE Online 08-04-2017]
question_answer44) There is a uniform electrostatic field in a region. The potential at various points on a small sphere centred at P, in the region, is found to vary between in limits 589.0V to 589.8 V. What is the potential at a point on the sphere whose radius vector makes an angle of \[60{}^\circ \] with the direction of the field? [JEE Online 08-04-2017]
question_answer45) Magnetic field in a plane electromagnetic wave is given by\[\vec{B}={{B}_{0}}\sin (kx+\omega t)\hat{j}T\] Expression for corresponding electric field will be [JEE Online 08-04-2017]
question_answer46) According to Bohr's theory, the time averaged magnetic field at the centre (i.e. nucleus) of a hydrogen atom due to the motion of electrons in the \[{{\text{n}}^{\text{th}}}\] orbit is proportional to : (n = principal quantum number) [JEE Online 08-04-2017]
question_answer47) Moment of inertia of an equilateral triangular lamina ABC, about the axis passing through its centre and perpendicular to its plane is I0 as shown in the figure. A cavithy DEF is cut out from the lamina, where D,E,F are the mid points of the sides. Moment of inertia of the remaining part of lamina about the same axis is [JEE Online 08-04-2017]
question_answer48) The maximum velocity of the photoelectrons emitted from the surface is v when light of frequency n falls on a metal surface. If the incident frequency is increased to 3n, the maximum velocity of the ejected photoelectrons will be - [JEE Online 08-04-2017]
question_answer49) What is the conductivity of a semiconductor sample having electron concentration of \[5\times {{10}^{18}}{{m}^{-3}},\] hole concentration of \[5\times {{10}^{19}}{{m}^{-3}},\] electron mobility of \[2.0{{m}^{2}}{{V}^{-1}}{{s}^{-1}}\]and hole mobility of \[0.01{{m}^{2}}{{V}^{-1}}{{s}^{-1}}\] (Take charge of electron as \[1.6\times {{10}^{-19}}C\]) [JEE Online 08-04-2017]
question_answer50) The V-I characteristic of a diode is shown in the figure. The ratio of forward to reverse bias resistance is : [JEE Online 08-04-2017]
question_answer52) A small circular loop of wire of radius a is located at the centre of a much larger circular wire loop of radius b. The two loops are in the same plane. The outer loop of radius b carries an alternating current \[I={{I}_{0}}\cos (\omega t).\]The emf induced in the smaller inner loop is nearly? [JEE Online 08-04-2017]
question_answer53) A 9 V battery with internal resistance of \[0.5\Omega \] is connected across an infinite network as shown in the figure. All ammeters A1, A2, A3 and voltmeter V are ideal. Choose correct statement. [JEE Online 08-04-2017]
question_answer54) Let the refractive index of a denser medium with respect to a rarer medium be \[{{n}_{12}}\]and its c critical angle be \[{{\theta }_{C}}.\]At an angle of incidence A when light is travelling from denser medium to rarer medium, a part of the light is reflected and the rest is refracted and the angle between reflected and refracted rays is \[90{}^\circ \]. Angle A given by - [JEE Online 08-04-2017]
question_answer55) The ratio of maximum acceleration to maximum velocity in a simple harmonic motion is \[10{{s}^{-1}}.\] [JEE Online 08-04-2017] At, t = 0 the displacement is 5 m. What is the maximum acceleration? The initial phase is\[\frac{\pi }{4}.\]
question_answer56) Two wires \[{{W}_{1}}\] and \[{{W}_{2}}\] have the same radius r and respective densities \[{{\rho }_{1}}\] and \[{{\rho }_{2}}\] such that\[{{\rho }_{2}}=4{{\rho }_{1}}.\]. They are joined together at the point O, as shown in the figure. The combination is used as a sonometer wire and kept under tension T. The point O is midway between the two bridges. When a stationary waves is set up in the composite wire, the joint is found to be a node. The ratio of the number of antinodes formed in \[{{W}_{1}}\]to \[{{W}_{2}}\] is - [JEE Online 08-04-2017]
question_answer57) An ideal gas has molecules with 5 degrees of freedom. The ratio of specific heats at constant pressure \[({{C}_{P}})\] and at constant volume \[({{C}_{V}})\]is [JEE Online 08-04-2017]
question_answer58) Two deuterons udnergo nuclear fusion to form a Helium nucleus. Energy released in this process is : [JEE Online 08-04-2017] (given binding energy per nucleon for deuteron = 1.1 MeV and for helium = 7.0 MeV)
question_answer59) In a certain region static electric and magentic fields exist. The magnetic field is given by \[\vec{B}={{B}_{0}}\left( \hat{i}+2\hat{j}-4\hat{k} \right).\]If a test charge moving with a velocity \[\vec{\upsilon }={{\upsilon }_{0}}\left( 3\hat{i}-\hat{j}+2\hat{k} \right)\]experience no force in that region, then the electric field in the region, in SI units, is - [JEE Online 08-04-2017]
question_answer60) In a physical balance working on the principle of moments, when 5 mg weight is placed on the left pan, the beam becomes horizontal. Both the empty pans of the balance are of equal mass. Which of the following statements is correct?
A)
Every object that is weighted using this balance appears lighter than its actual weight
question_answer61) If the shortest wavelength in Lyman series of hydrogen atom is A, then the longest wavelength in Paschen series of \[H{{e}^{+}}\] is : [JEE Online 08-04-2017]
question_answer63) Identify the pollutant gases largely responsible for the discoloured and lustreless nature of marble of the Taj Mahal. [JEE Online 08-04-2017]
question_answer66) The rate of a reaction A doubles on increasing the temperature from 300 to 310 K. By how much, the temperature of reaction B should be increased from 300 K so that rate doubles if activation energy of the reaction B is twice to that of reaction A. [JEE Online 08-04-2017]
question_answer67) A solution containing a group-IV cation gives a precipitate on passing, \[{{H}_{2}}S.\]. A solution of this precipitate in dil. HCl produces a white precipitate with NaOH solution and bluish-white precipitate with basic potassium ferrocyanide. The cation is : [JEE Online 08-04-2017]
question_answer69) Excess of NaOH (aq) was added to 100 mL of \[FeC{{l}_{3}}\](aq) resulting into 2.14 g of \[Fe{{(OH)}_{3}}.\] The molarity of \[FeC{{l}_{3}}\](aq) is : (Given molar mass of \[Fe=56gmo{{l}^{-1}}\]and molar mass of \[Cl=35.5gmo{{l}^{-1}}\]) [JEE Online 08-04-2017]
question_answer70) 5 g of\[N{{a}_{2}}S{{O}_{4}}\] was dissolved in x g of \[{{H}_{2}}O.\] The change in freezing point was found to be \[3.82{}^\circ C\]. If \[N{{a}_{2}}S{{O}_{4}}\] is 81.5% ionised, the value of x (\[{{K}_{f}}\] for \[water=1.86{}^\circ C\] kg \[\text{mo}{{\text{l}}^{\text{-1}}}\]) is approximately: (molar mass of S = 32 g \[\text{mo}{{\text{l}}^{\text{-1}}}\] and that of Na = 23 g\[\text{mo}{{\text{l}}^{\text{-1}}}\]) [JEE Online 08-04-2017]
question_answer71) Consider the following standard electrode potentials (\[E{}^\circ \] in volts) in aqueous solution : \[\frac{\text{Element}}{\begin{align} & \text{Al} \\ & \text{TI} \\ \end{align}}\] \[\frac{{{\text{M}}^{\text{3+}}}\text{/M}}{\begin{align} & \text{-1}\text{.66} \\ & \text{+1}\text{.26} \\ \end{align}}\] \[\frac{{{\text{M}}^{\text{+}}}\text{/M}}{\begin{align} & \text{+0}\text{.55} \\ & \text{-0}\text{.34} \\ \end{align}}\] Based on these data, which of the following statements is correct? [JEE Online 08-04-2017]
A)
\[T{{\ell }^{3+}}\] is more stable than \[A{{\ell }^{3+}}\]
doneclear
B)
\[A{{\ell }^{+}}\]is more stable than \[A{{\ell }^{3+}}\]
doneclear
C)
\[T{{\ell }^{3+}}\] is more stable than \[A{{\ell }^{3+}}\]
doneclear
D)
\[T{{\ell }^{+}}\]is more stable than \[A{{\ell }^{+}}\]
question_answer76) A mixture containing the following four compounds is extracted with 1 M HCl. The compound that goes to aqueous layer is: [JEE Online 08-04-2017]
question_answer79) The number of S = O and S-OH bonds present in peroxodisulphuric acid and pyrosulphuric acid respectively are : [JEE Online 08-04-2017]
question_answer81) The major product of the following reaction is: [JEE Online 08-04-2017] \[{{C}_{6}}{{H}_{5}}C{{H}_{2}}-\underset{\begin{smallmatrix} | \\ Br \end{smallmatrix}}{\overset{\begin{smallmatrix} C{{H}_{3}} \\ | \end{smallmatrix}}{\mathop{C}}}\,-C{{H}_{2}}-C{{H}_{3}}\xrightarrow[{{C}_{2}}{{H}_{5}}OH]{{{C}_{2}}{{H}_{5}}ONa}\]
question_answer82) What is the standard reduction potential \[(E{}^\circ )\] for \[F{{e}^{3+}}\to Fe\]? Given that: [JEE Online 08-04-2017] \[F{{e}^{2+}}+2{{e}^{-}}\to Fe;{{E}^{o}}_{F{{e}^{2+}}/Fe}=-0.47V\] \[F{{e}^{3+}}+{{e}^{-}}\to F{{e}^{2+}};{{E}^{o}}_{F{{e}^{3+}}/F{{e}^{2+}}}=+0.77V\]
question_answer85) The major product of the following reaction is: \[C{{H}_{3}}\underset{\begin{smallmatrix} | \\ Br \end{smallmatrix}}{\mathop{C}}\,HC{{H}_{2}}\underset{\begin{smallmatrix} | \\ Br \end{smallmatrix}}{\mathop{C}}\,C{{H}_{2}}C{{H}_{3}}\xrightarrow[heat]{KOH,C{{H}_{3}}OH}\] [JEE Online 08-04-2017]
question_answer88) The enthalpy change on freezing of 1 mol of water at \[5{}^\circ C\] to ice at \[-5{}^\circ C\] is : (Given \[{{\Delta }_{fus}}H=6kJ\,mo{{l}^{-1}}\]at \[0{}^\circ C\], \[{{C}_{p}}({{H}_{2}}O,\ell )=75.3J\,mo{{l}^{-1}}{{K}^{-1}},\] \[{{C}_{p}}({{H}_{2}}O,s)=36.8J\,mo{{l}^{-1}}{{K}^{-1}})\] [JEE Online 08-04-2017]
question_answer89) Addition of sodium hydroxide solution to a weak acid (HA) results in a buffer of pH 6. If ionization constant of HA is 10-5, the ratio of salt to acid concentration in the buffer solution will be : [JEE Online 08-04-2017]
question_answer90) A metal 'M' reacts with nitrogen gas to afford \['{{M}_{3}}N'.'{{M}_{3}}N'\] on heating at high temperature gives back 'M' and on reaction with water produces a gas 'B'. Gas 'B' reacts with aqueous solution of \[CuS{{O}_{4}}\]to form a deep blue compound. 'M' and 'B' respectively are : [JEE Online 08-04-2017]