Solved papers for JCECE Engineering JCECE Engineering Solved Paper-2008
done JCECE Engineering Solved Paper-2008 Total Questions - 150
question_answer1) A particle moves in a straight line with retardation proportional to its displacement. Its loss of kinetic energy for any displacement \[x\] is proportional to
question_answer2) A ball is thrown from a point with a speed \[{{v}_{0}}\] at an angle of projection\[\theta \]. From the same point and at the same instant, a person starts running with a constant speed \[\frac{{{v}_{0}}}{2}\] to catch the ball. Will the person be able to catch the ball? If yes, what should be the angle of projection?
question_answer3) Spherical balls of radius \[R\] are falling in a viscous, fluid of viscosity \[\eta \] with a velocity\[v\]. The retarding viscous force acting on the spherical ball is
A)
directly proportional to \[R\] but inversely proportional to\[v\]
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B)
directly proportional to both radius \[R\] and velocity\[v\]
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C)
inversely proportional to both radius \[R\] and velocity\[v\]
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D)
inversely proportional to \[R\] but directly proportional to velocity\[v\]
question_answer6) What is the value of inductance \[L\] for which the current is a maximum in a series \[LCR\] circuit with\[C=10\mu F\]and\[\omega =1000{{s}^{-1}}\]?
question_answer7) Three point charges \[+q,\,\,-2q\]and\[+q\] are placed at points \[(x=0,\,\,y=a,\,\,z=0),\]\[(x=0,\,\,y=0,\,\,z=0)\]and\[(x=a,\,\,y=0,\,\,z=0)\], respectively. The magnitude and direction of the electric dipole moment vector of this charge assembly are
A)
\[\sqrt{2}qa\]along\[+y\]direction
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B)
\[\sqrt{2}qa\]along the line joining points \[(x=0,\,\,y=0,\,\,z=0)\] and \[(x=a,\,\,y=a,\,\,z=0)\]
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C)
\[qa\]along the line joining points \[(x=0,\,\,y=9,\,\,z=0)\] and \[(x=a,\,\,y=a,\,\,z=0)\]
question_answer8) The following figure shows a logic gate circuit with two inputs \[A\] and \[B\] and the output\[C\]. The voltage waveforms of \[A,\,\,\,B\] and \[C\] are as shown below The logic circuit gate is
question_answer9) Assuming the sun to have a spherical outer surface of radius\[r\], radiating like a black body at temperature\[{{t}^{o}}C\], the power received by a unit surface, (normal to the incident rays) at a distance \[R\] from the centre of the sun is
question_answer10) The temperature of the two outer surfaces of a composite slab, consisting, of two materials having coefficients of thermal conductivity \[K\] and \[2K\] \[\text{and}\] thickness \[x\] and\[4x\], respectively are \[{{T}_{2}}\] and \[{{T}_{1}}\]\[({{T}_{2}}>{{T}_{1}})\]. The rate of heat transfer through the slab, in a steady state is\[\left( \frac{A({{T}_{2}}-{{T}_{1}})K}{x} \right)f\], with\[f\]equals to
question_answer11) The maximum number of possible interference maxima for slit-separation equal to twice the wavelength in Young's double-slit experiment, is
question_answer12) Two spherical conductors \[B\] and \[C\] having equal radii and carrying equal charges in them repel each other with a force \[F\] when kept apart at some distance. A third spherical conductor having same radius as that of \[B\] but uncharged, is brought in contact with\[B\], then brought in contact with \[C\] and finally removed away from both. The new force of repulsion between \[B\] and \[C\] is
question_answer14) A particle starting from the origin \[(0,\,\,0)\] moves in a straight line in the \[(x,\,\,y)\] plane. Its coordinates at a later time are\[(\sqrt{3},\,\,3)\]. The path of the particle makes with the \[x-\]axis an angle of
question_answer15) The resistance of an ammeter is \[13\Omega \] and its scale is graduated for a current upto\[100\,\,A\]. After an additional shunt has been connected to this ammeter it becomes possible to measure currents upto \[750\,\,A\] by this meter. The value of shunt resistance is
question_answer16) The primary and secondary coils of a transformer have \[50\] and \[1500\] turns respectively. If the magnetic flux \[\phi \] linked with the primary coil is given by \[\phi ={{\phi }_{0}}+4t\], where \[\phi \] is in weber, \[t\] is time in second and \[{{\phi }_{0}}\] is a constant, the output voltage across the secondary coil is
question_answer17) A uniform rod \[AB\] of length \[l\] and mass \[m\] is free to rotate about point\[A\]. The rod is released from rest in the horizontal position. Given that the moment of inertia of the rod about \[A\] is \[\frac{m{{l}^{2}}}{3}\] the initial angular acceleration of the rod will be
question_answer18) In the energy band diagram of a material shown below, the open circles and filled circles denote holes and electrons respectively. The material is a/an
question_answer19) A particle executes simple harmonic oscillation with an amplitude\[a\]. The period of oscillation is\[T\]. The minimum time taken by the particle to travel half of the amplitude from the equilibrium position is
question_answer20) A block \[B\] is pushed' momentarily along a horizontal surface with an initial velocity\[v\]. If \[\mu \] is the coefficient of sliding friction between \[B\] and the surface, block \[B\] will come to rest after a time
question_answer21) A transformer is used to light \[\text{a}\] \[100\,\,W\] and \[110\,\,V\] lamp from a \[220\,\,V\] mains. If the main current is \[0.5\,\,A\], the efficiency of the transformer is approximately
question_answer22) A steady current of \[1.5\,\,A\] flows through a copper voltameter for \[10\,\,\min \]. If the electrochemical equivalent of copper is\[30\times {{10}^{-5}}g\,\,{{C}^{-1}}\], the mass of copper deposited on the electrode will be
question_answer23) Three resistances \[P,\,\,\,Q,\,\,\,R\] each of \[2\,\,\Omega \] and an unknown resistance \[S\] form the four arms of a Wheatstone's bridge circuit. When a resistance of \[6\,\,\Omega \] is connected in parallel to \[S\] the bridge gets balanced. What is the value of\[S?\]
question_answer24) A mass of \[2.0\,\,kg\] is put on a flat pan attached to a vertical spring fixed on the ground as shown in the figure. The mass of the spring and the pan is negligible. When pressed slightly and released the mass-executes a simple harmonic motion. The spring constant is \[200\,\,N/m\]. What should be the minimum amplitude of the motion, so that the mass gets detached from the pan? (Take\[g=10m/{{s}^{2}})\]
question_answer25) Two satellites of earth, \[{{S}_{1}}\] and \[{{S}_{2}}\], are moving in the same orbit. The mass of \[{{S}_{2}}\] is four times the mass of \[{{S}_{2}}\]. Which one of the following statements is true?
A)
The time period of \[{{S}_{1}}\] is four times that of\[{{S}_{2}}\].
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B)
The potential energies of earth and satellite in the two cases are equal.
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C)
\[{{S}_{1}}\] and \[{{S}_{2}}\] are moving with the same speed.
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D)
The kinetic energies of the two satellites are equal.
question_answer26) Charges \[+q\] and \[-q\] are placed at points \[A\] and \[B\] respectively which are a distance 2E apart, \[C\] is the midpoint between \[A\] and \[B\]. The work done in moving a charge \[+Q\] along the semicircle \[CRD\] is
question_answer27) A beam of electrons passes un deflected through mutually perpendicular electric and magnetic fields. If the electric field is switched off, and the same magnetic field is maintained, the electrons move
question_answer28) Monochromatic light of frequency \[6.0\times {{10}^{14}}Hz\] is produced by a laser. The power emitted is\[2\times {{10}^{-3}}W\]. The number of photons emitted, on the average, by the source per second is
question_answer29) The diagram shows the energy levels for an electron in a certain atom. Which transition shown represents the emission of a photon with the most energy?
question_answer30) In the circuit, the galvanometer \[G\] shows zero deflection. If the batteries \[A\] and \[B\] have negligible internal resistance, the value of the resistor \[R\] will be
question_answer31) When an un polarized light of intensity \[{{I}_{0}}\] is incident on a polarizing sheet, the intensity of the light which does not get transmitted is
question_answer32) An observer moves towards a stationary source of sound, with a velocity one-fifth of the velocity of sound. What is the percentage increase in the apparent frequency?
question_answer33) A particle of mass 100 g is thrown vertically upwards with a speed of 5 m/s. The work done by the force, of gravity during the time the particle goes up is
question_answer34) A mass of \[M\,\,kg\] is suspended by a weightless string. The horizontal force that is required to displace it until the string makes an angle of \[{{45}^{o}}\] with the initial vertical direction is
question_answer35) An electric charge \[{{10}^{-3}}\mu C\] is placed at the origin \[(0,\,\,0)\] of \[X-Y\] coordinate system. Two points \[A\] and \[B\] are situated at \[(\sqrt{2},\,\,\sqrt{2})\] and \[(2,\,\,0)\] respectively. The potential difference between the points \[A\] and \[B\] will be
question_answer36) A circular disc of radius \[R\] is removed from a bigger circular disc of radius \[2R\], such that the circumference of the discs coincide. The centre of mass of the new disc is \[\alpha R\] from the centre of the bigger disc. The value of \[\alpha \] is
question_answer37) A common-emitter amplifier has a voltage gain of\[50\], an input impedance of \[100\,\,\Omega \] and an output impedance of \[200\,\,\Omega \]. The power gain of the amplifier is
question_answer38) A vertical spring with force constant \[k\] is fixed on a table. A ball of mass \[m\] at a height \[h\] above the free upper end of the spring falls vertically on the spring, so that the spring is compressed by a distance\[d\]. The net work done in the process is
question_answer39) Dimensions of resistance in an electrical circuit, in terms of dimension of mass\[M\], of length\[L\], of time \[T\] and of current\[I\], would be
question_answer40) The work of \[146\,\,kJ\] is performed in order to compress one kilo mole of a gas adiabatically and in this process the temperature of the gas increases by\[{{7}^{o}}C\]. The gas is \[(R=8.3\,\,J\,\,mo{{l}^{-1}}{{K}^{-1}})\]
question_answer42) A frame made of metallic wire enclosing a surface area \[A\] is covered with a soap film. If the area of the frame of metallic wire is reduced by\[50%\], the energy of the Soap film will be changed by
question_answer43) A symmetric double convex lens is cut in two equal parts by a plane perpendicular to the principal axis. If the power of the original lens is\[4D\], the power of a cut lens will be
question_answer44) Two non-ideal batteries are connected in parallel. Consider the following statements. (i) The equivalent emf is smaller than either of the two emfs. (ii) The equivalent internal resistance is smaller than either of the two internal resistances.
question_answer45) The period of oscillation of a simple pendulum is given by\[T=2\pi \sqrt{\frac{l}{g}}\], where \[l\] is about \[100\,\,cm\] and is known to have \[1\,\,mm\] accuracy. The period is about \[2s\]. The time of \[100\] oscillations is measured by a stop watch of least count\[0.1s\]. The percentage error in \[g\] is
question_answer46) The mass of the earth is \[6.00\times {{10}^{24}}kg\] and that of the moon is\[7.40\times {{10}^{22}}kg\]. The constant of gravitation\[G=6.67\times {{10}^{-11}}N\text{-}{{m}^{2}}/k{{g}^{2}}\]. The potential energy of the system is\[-7.79\times {{10}^{28}}J\]. The mean distance between the earth and moon is
question_answer47) If a rubber ball is taken at the depth of \[200\,\,m\] in a pool, its volume-decreases by \[0.1%\]. If the density of water is \[1\times {{10}^{3}}kg/{{m}^{3}}\] and \[g=10\,\,m/{{s}^{2}}\], then the volume of elasticity in \[N/{{m}^{2}}\] will be
question_answer48) At \[100\,\,K\]and \[0.1\] atmospheric pressure, the volume of helium gas is\[10\,\,L\]. If volume and pressure are doubled its temperature will change to
question_answer49) An organ pipe \[{{P}_{1}}\] closed at one end vibrating in its first overtone and another pipe \[{{P}_{2}}\] open at both ends vibrating in its third overtone are in resonance with a given tuning fork. The ratio of lengths of \[{{P}_{1}}\] and \[{{P}_{2}}\] is
question_answer51) How many unit cells are present in a cube shaped ideal crystal of \[NaCl\] \[\text{of}\] mass\[1.00\,\,g\]? [Atomic masses\[Na=23,\,\,Cl=35.5]\]
question_answer52) In acidic medium dichromate ion oxidises ferrous ion to ferric ion. If gram molecular weight of potassium dichromate is \[294\,\,g\], its gram equivalent weight is
question_answer55) For the redox reaction \[Zn(s)+C{{u}^{2+}}(0.1\,\,M)\xrightarrow{{}}Z{{n}^{2+}}(1\,\,M)+Cu(s)\] taking place in a cell,\[E_{cell}^{\text{o}}\]is\[1.10\,\,V\].\[{{E}_{cell}}\]for the cell will be\[\left( 2.303\frac{RT}{F}=0.0591 \right)\]
question_answer56) The rate law for a reaction between the substances \[A\] and \[B\] is given by rate\[=k{{[A]}^{n}}{{[B]}^{n}}\]. On doubling the concentration of \[A\] and halving the concentration of \[B\], the ratio of the new rate to the earlier rate of the reaction will be as
question_answer57) If at \[298\,\,K\] the bond energies of \[C-H,\,\,C-C,\,\,C=C\] and \[H-H\] bonds are respectively \[414,\,\,347,\,\,615\] and\[435\,\,kJ\,\,mo{{l}^{-1}}\], the value of enthalpy change for the reaction \[{{H}_{2}}C=C{{H}_{2}}(g)+{{H}_{2}}(g)\xrightarrow{{}}{{H}_{3}}C-C{{H}_{3}}(g)\]at \[298\,\,K\] will be
question_answer63) Aluminium oxide may be electrolysed at \[{{1000}^{o}}C\] to furnish aluminium metal (atomic mass\[=27\,\,u;\,\,1F=96500\,\,C)\]. The cathode reaction is\[A{{l}^{3+}}+3{{e}^{-}}\xrightarrow{{}}A{{l}^{0}}\] To prepare \[5.12\,\,kg\] of aluminium metal by this method would require
question_answer68) An aqueous solution of \[6.3\,\,g\] of oxalic acid dihydrate is made upto \[250\,\,mL\]. The volume of \[0.1\,\,N\,\,NaOH\] required to completely neutralise \[10\,\,mL\] of this solution is
question_answer69) The wavelength of the radiation emitted, when in a hydrogen atom electron falls from infinity to stationary state one, would be (Rydberg constant\[=1.097\times {{10}^{7}}{{m}^{-1}})\]
question_answer73) The enthalpies of combustion of carbon and carbon monoxide are \[-393.5\] and \[-283\,\,kJ\,\,mo{{l}^{-1}}\] respectively. The enthalpy of formation of carbon monoxide per mol is
question_answer75) Excess of \[KI\] reacts with \[CuS{{O}_{4}}\] solution and then \[N{{a}_{2}}{{S}_{2}}{{O}_{3}}\] solution is added to it. Which of the statements is incorrect for this reaction?
question_answer78) Consider the acidity of the carboxylic acids (i)\[PhCOOH\] (ii)\[o-N{{O}_{2}}{{C}_{6}}{{H}_{4}}COOH\] (iii)\[p-N{{O}_{2}}{{C}_{6}}{{H}_{4}}COOH\] (iv)\[m-N{{O}_{2}}{{C}_{6}}{{H}_{4}}COOH\] Which of the following orders is correct?
question_answer81) The radioisotope, tritium \[(_{1}^{3}H)\] has a half-life of \[12.3\,\,yr\]. If the initial amount of tritium is\[32\,\,mg\], how many milligrams of it would remain after\[49.2\,\,yr?\]
question_answer82) In this reaction\[C{{H}_{3}}CHO+HCN\xrightarrow{{}}C{{H}_{3}}CH(OH)CN\] \[\xrightarrow{H\cdot OH}C{{H}_{3}}CH(OH)COOH\]an asymmetric centre is generated. The acid obtained would be
question_answer84) The temperature dependence of rate constant \[(k)\] of a chemical reaction is written in terms of Arrhenius equation\[,\]\[k=A{{e}^{-{{E}^{*}}/RT}}\]. Activation energy \[({{E}^{*}})\] of the reaction can be calculated by ploting
question_answer85) In a set of the given reactions, acetic acid yielded a product\[C\]. \[C{{H}_{3}}COOH+PC{{l}_{5}}\xrightarrow{{}}A\]\[A\xrightarrow[anhy\,\,AlC{{l}_{3}}]{{{C}_{6}}{{H}_{6}}}B\xrightarrow[ether]{{{C}_{2}}{{H}_{5}}MgBr}C\]Product \[C\] would be
question_answer91) The radioactive isotope \[_{27}^{60}Co\] which is used to the treatment of cancer can be made by \[(n,\,\,p)\] reaction. For this reaction the target nucleus is
question_answer92) The vapour pressure of two liquids \[P\] and \[Q\] are \[80\] and \[60\]\[Torr\], respectively. The total vapour pressure of solution obtained by mixing \[3\] moles of \[P\] and \[2\] moles of \[Q\] would be
question_answer93) The energy of second Bohr. orbit of the hydrogen atom is \[-328\,\,kJ\,\,mo{{l}^{-1}}\]; hence the energy of fourth Bohr orbit would be
question_answer99) The dipole moment of \[HBr\] is \[1.6\times {{10}^{-3}}C\text{-}m\] and inter-atomic spacing is \[1\,\,A\]. The, \[%\] ionic character of \[HBr\] is
question_answer101) If \[\overset{\to }{\mathop{\mathbf{a}}}\,\] is perpendicular to \[\overset{\to }{\mathop{\mathbf{b}}}\,\] and \[\overset{\to }{\mathop{c}}\,,\,\,\,|\overset{\to }{\mathop{\mathbf{a}}}\,|=2,\]\[|\overset{\to }{\mathop{\mathbf{b}}}\,|=3\] the angle between \[\overset{\to }{\mathop{\mathbf{b}}}\,\] and \[\overset{\to }{\mathop{\mathbf{c}}}\,\] is\[\frac{2\pi }{3}\], then \[[\overrightarrow{\mathbf{a}}\overrightarrow{\mathbf{b}}\overrightarrow{\mathbf{c}}]\] is equal to
question_answer103) The vector \[\widehat{\mathbf{i}}+x\widehat{\mathbf{j}}+3\widehat{\mathbf{k}}\] is rotated through an angle \[0\] and doubled in magnitude, then it becomes\[4\widehat{\mathbf{i}}+(4x-2)\widehat{\mathbf{j}}+2\widehat{\mathbf{k}}\]. The value of \[x\] is
question_answer104) Three forces of magnitude \[30,\,\,\,60\] and \[P\] acting at a point are in equilibrium. If the angle between the first two is\[{{60}^{o}}\], then value of \[P\] is
question_answer110) The equation of tangents to the ellipse\[\frac{{{x}^{2}}}{9}+\frac{{{y}^{2}}}{4}=1\], which are perpendicular to the line \[3x+4y=7\], are
question_answer111) From the point \[P(16,\,\,7)\] tangents \[PQ\] and \[PR\] are drawn to the circle\[{{x}^{2}}+{{y}^{2}}-2x-4y-20=0\].If\[c\]be the centre of the circle, then area of quadrilateral \[PQCR\] is
question_answer114) The records of a hospital show that \[10%\] of the cases of a certain disease are fatal. If \[6\] patients are suffering from the disease, then the probability that only three will die, is
question_answer117) If \[\alpha ,\,\,\,\beta \] are the roots of the equation \[l{{x}^{2}}+mx+n=0\], then the equation whose roots are \[{{\alpha }^{3}}\beta \] and \[\alpha {{\beta }^{3}}\], is
question_answer119) Out of \[6\] boys and \[4\] girls, a group of \[7\] is to be formed. In how many ways can this be done, if the group is to have a majority of boys?
question_answer126) The radical centre of the circles \[{{x}^{2}}+{{y}^{2}}-16x+60=0\], \[{{x}^{2}}+{{y}^{2}}-12x+27=0\] and \[{{x}^{2}}+{{y}^{2}}-12y+8=0\]is
question_answer128) A ball falls from rest from top of a tower. If the ball reaches the foot of the tower in \[3\,\,s\], then height of tower is (take\[g=10\,\,m/{{s}^{2}})\]
question_answer132) If the radius of a circle be increasing at a uniform rate of \[2\,\,cm/s\]. The area of increasing of area of circle, at the instant when the radius is \[20\,\,cm\], is
question_answer136) Let the functions \[f,\,\,\,g,\,\,\,h\] are defined from the set of real numbers \[R\] to \[R\] such that \[f(x)={{x}^{2}}-1,\,\,g(x)=\sqrt{({{x}^{2}}+1)}\]and \[h(x)=\left\{ \begin{matrix} 0,if & x\le 0 \\ x,if & x\ge 0 \\ \end{matrix} \right.\], then \[ho(fog)(x)\]is defined by
question_answer144) Let \[\overset{\to }{\mathop{\mathbf{a}}}\,,\,\,\,\overset{\to }{\mathop{\mathbf{b}}}\,\] and \[\overset{\to }{\mathop{\mathbf{c}}}\,\] be vectors with magnitudes \[3,\,\,\,4\]and \[5\] respectively and \[\overrightarrow{\mathbf{a}}+\overrightarrow{\mathbf{b}}+\overrightarrow{\mathbf{c}}=0\], then the values of \[\overrightarrow{\mathbf{a}}\cdot \overrightarrow{\mathbf{b}}+\overrightarrow{\mathbf{b}}\cdot \overrightarrow{\mathbf{c}}+\overrightarrow{\mathbf{c}}\cdot \overrightarrow{\mathbf{a}}\] is
question_answer145) From a point a metre above a lake the angle of elevation of a cloud \[\alpha \] and the angle of depression of its reflection is \[\beta \]. The height of the cloud is