Solved papers for JCECE Engineering JCECE Engineering Solved Paper-2014
done JCECE Engineering Solved Paper-2014 Total Questions - 150
question_answer1) A mass of \[0.5\,\,kg\] moving with a speed of \[1.5\,\,m{{s}^{-1}}\] on a horizontal smooth surface, collides with a nearly weightless spring of force constant\[k=50\,\,N{{m}^{-1}}\]. The maximum compression of the spring would be
question_answer2) A particle of mass \[{{m}_{1}}\] moves with velocity \[{{\upsilon }_{1}}\] and collides with another particle at rest of equal mass. The velocity of the second particle after the elastic collision is
question_answer3) The ratio of the radii of gyration of a circular disc to that of a circular ring, each of same mass and radius, around their respective axis is
question_answer4) A wheel having moment of inertia\[2kg\,\,{{m}^{-2}}\] about its vertical axis, rotates at the rate of \[60\,\,rpm\] about this axis. The torque which can stop the wheel's rotation in one minute would be
question_answer5) A sphere of diameter \[0.2\,\,m\] and mass \[2\,\,kg\] is rolling on an inclined plane with velocity\[v=0.5m{{s}^{-1}}\]. The kinetic energy of the sphere is
question_answer6) If a sphere rolling on an inclined plane with velocity v without slipping, the vertical height of the incline in terms of velocity will be
question_answer7) The height vertically above the earth's surface at which the acceleration due to gravity becomes \[1%\] of its value at the surface is (\[R\] is the radius of the earth)
question_answer8) The motion of a particle executing SHM in one dimension is described by\[x=-0.23\sin \left( t+\frac{\pi }{4} \right)\]where, \[x\] is in metre and t in second. The frequency of oscillation in \[Hz\] is
question_answer9) The change in the gravitational potential energy when a body of mass \[m\] is raised to a height \[nR\] above the surface of the earth is (here, \[R\] is the radius of the earth)
question_answer10) A satellite is rotating around a planet in the orbit of radius \[r\] with time period\[T\]. If gravitational force changes according to\[{{r}^{5/2}}\], the \[{{T}^{2}}\] will be
question_answer11) A liquid \[X\] of density \[3.36\,\,g/c{{m}^{3}}\] is poured in a U-tube in right arm with height\[10\,\,cm\], which contains\[Hg\]. Another liquid \[Y\] is poured in left arm with height\[8\,\,cm\]. Upper levels of \[X\] and \[Y\] are same. What is the density of\[Y\]?
question_answer12) Wafer flows along a horizontal pipe whose cross-section is not, constant. The pressure is \[1\,\,cm\] of\[Hg\], where the velocity is\[35\,\,cm{{s}^{-1}}\]. At a point where the velocity is\[65\,\,cm{{s}^{-1}}\], the pressure will be
question_answer13) A lead bullet of unknown mass is fired-with a speed of \[180\,\,m{{s}^{-1}}\] into a tree in which it stops. Assuming that in this process two-third of heat produced goes into the bullet and one-third into wood. The temperature of the bullet rises by
question_answer15) Two monoatomic ideal gases \[A\] and \[B\] occupying the same volume \[V\] are at the same temperature \[T\] and pressure\[p\]. If they are mixed, the resultant mixture has volume \[V\] and temperature\[T\]. The pressure of the mixture is
question_answer16) The temperature at which the mean \[KE\] of the molecules of gas is one-third of the mean \[KE\] of its molecules at \[{{180}^{o}}C\] is
question_answer17) \[U\] is the \[PE\] of an oscillating particle and \[F\] is the force acting on it at a given instant. Which of the following is true?
question_answer18) The density of newly discovered planet is twice that of the earth. The acceleration due to gravity at the surface of the planet is equal to that at the surface of the earth. If the radius of the earth is\[R\], the radius of the plane would be
question_answer19) The half-life period of a radioactive substance is\[140\,\,days\]. After, how much time, \[15\,\,g\] will decay from a \[16\,\,g\] sample of the substance?
question_answer20) A tuning fork \[A\] produces 4 beats \[{{s}^{-1}}\] with another tuning fork \[B\] of frequency\[320\,\,Hz\]. On filing one of the prongs of\[A\], 4 beats \[{{s}^{-1}}\] are again heard when sounded with the same fork\[B\]. Then, the frequency of 'the fork A before filing is
question_answer21) Two cars are moving on two perpendicular roads towards a crossing with uniform speeds of\[72\,\,km/h\]\[\text{and}\]\[36\,\,km/h\]. If first car blows horn of frequency\[280\,\,Hz\], then the frequency of horn heard by the driver of second car when line joining the car makes angle of \[{{45}^{o}}\] with the roads, will.be
question_answer22) A particle moves along a straight line\[OX\]. At a time \[t\] (in second) the distance \[x\] of the particle from \[O\] is given by\[x=40+12t-{{t}^{3}}\]. How long would the particle travel before coming to rest?
question_answer24) The electric field due to an electric dipole at a distance \[r\] from its centre in axial position is\[E\]. If the dipole is rotated through an angle of \[{{90}^{o}}\] about its perpendicular axis, the electric field at the same point will be
question_answer26) A charge \[q\] coulomb makes \[n\] revolutions in one second in a circular orbit of radius r. The magnetic field at the centre of the orbit in\[N{{A}^{-1}}{{m}^{-1}}\]is.
question_answer28) The couple acting on a magnet of length \[10\,\,cm\] and pole strength\[125\,\,A-m\], kept in a field of \[B=2\times {{10}^{-5}}T\], at an angle of \[{{30}^{o}}\] is
question_answer29) \[X\]and\[Y\], two metallic coils are arranged in such a way that, when steady change in current flowing in \[X\] coil is\[4\,\,A\], change in magnetic flux associated with coil \[Y\] is\[0.4\,\,Wb\]. Mutual inductance of the system of these coils is
question_answer30) A sinusoidal voltage of peak value \[300\,\,V\] and an angular frequency \[\omega =400\,\,rad/s\] is applied to series \[L-C-R\] circuit, in which \[R=3\Omega ,\,\,L=20\,\,mH\]and\[C=625\mu F\]. The peak current in the circuit is
question_answer33) The magnification produced by an astronomical telescope for normal adjustment is 10 and the length of the telescope.is\[1.1\,\,m\]. The magnification, when the image is formed atleast distance of distinct vision is
question_answer34) In Young's double slit experiment with sodium vapour lamp of wavelength \[589\,\,nm\] and the slits \[0.589\,\,mm\] apart, the half angular width of the central maximum is
question_answer35) When the angle of incidence is \[{{60}^{o}}\] on the surface of a glass slab, it is found that the reflected ray is completely polarised. The velocity of light in glass is
question_answer36) Cathode rays of velocity \[{{10}^{6}}m{{s}^{-1}}\] describe an approximate circular path of radius \[1\,\,m\] in an electric field\[300\,\,Vc{{m}^{-1}}\]. If the velocity of the cathode rays are doubled. The value of electric field so that the rays describe the same circular path, will be
question_answer37) The de-Broglie wavelength of an electron and the wavelength of a photon are the same. The ratio between the energy of that photon and the momentum of that electron is (\[c=\]velocity of light, \[h=\]Planck's constant)
question_answer38) When \[1\,\,cm\]thick surface is illuminated with light of wavelength\[\lambda \], the stopping potential is\[V\]. When the same surface is illuminated by light of wavelength\[2\lambda \], the stopping potential is\[\frac{V}{3}\]. Threshold wavelength for metallic surface is
question_answer39) For photoelectric emission, tungsten requires light of\[2300\,\,\overset{\text{o}}{\mathop{\text{A}}}\,\]. If light of \[1800\,\,\overset{\text{o}}{\mathop{\text{A}}}\,\] wavelength is incident, then emission
question_answer41) The frequency of vibration of string is given by \[v=\frac{p}{2l}{{\left[ \frac{F}{m} \right]}^{1/2}}\] Here, \[p\] is the number of segments m the string and \[l\] is the length. The dimensional formula for \[m\] will be
question_answer42) A stone is thrown vertically upwards. When the stone is at a height equal to half of its maximum height its speed will be\[10\,\,m/s\], then the maximum height attained by the stone (Take\[g=10\,\,m/{{s}^{2}})\]
question_answer43) A string of length /fixed at one end carries mass \[m\] at the other end. The string makes\[\frac{2}{\pi }\,\,rev/s\] around the horizontal axis through the it fixed end as shown in the figure, the tension in the string is
question_answer44) A gardener pushes a lawn roller through distance\[20\,\,m\]. If he applies a force of \[20\,\,kg-w\] in a direction inclined at \[{{60}^{o}}\] to the ground, the work done by him is
question_answer46) \[Li\] nucleus has three protons and four neutrons. Mass of lithium nucleus is\[7.016005\,\,amu\]. Mass of proton is \[1.007277\,\,amu\] and mass of neutron is\[1.008665\,\,amu\]. Mass defect for lithium nucleus in \[amu\] is
question_answer48) The values of two resistors are \[{{R}_{1}}=(6+0.3)k\Omega \] and\[{{R}_{2}}=(10\pm 0.2)k\Omega \]. The percentage error in the equivalent resistance when, they are connected in parallel is
question_answer49) A body of mass \[2\,\,kg\] is projected from the ground with a velocity \[20\,\,m{{s}^{-1}}\] at an angle \[{{30}^{o}}\] with the vertical. If \[{{t}_{1}}\] is the time in second at which the body is projected and \[{{t}_{2}}\] is the time in second at which it reaches the ground, the change in momentum in \[kgm{{s}^{-1}}\] during the time \[({{t}_{2}}-{{t}_{1}})\] is
question_answer50) The position vector of a particle is\[r=(a\cos \omega t)\widehat{\mathbf{i}}+(a\sin \omega t)\widehat{\mathbf{j}}\]. The velocity vector of the particle is
question_answer60) The complex \[{{[Fe{{({{H}_{2}}O)}_{5}}NO]}^{2+}}\] is formed in the brown ring test for nitrates when freshly prepared \[FeS{{O}_{4}}\] solution is added to aqueous solution of \[NO_{3}^{-}\] followed by addition of conc. \[{{H}_{2}}S{{O}_{4}}\]. Select the correct statement about this complex.
A)
Colour change is due to charge transfer
doneclear
B)
It has iron in \[+1\] oxidation state and nitrosyl as\[N{{O}^{+}}\]
doneclear
C)
It has, magnetic moment of \[3.87\,\,BM\] confirming three unpaired electrons in\[Fe\]
question_answer61) Consider the following statements. I. Colour of a transition metal complex is dependent on energy difference between two \[d-\]levels. II. Colour of the complex is dependent on the nature of the ligand and the type of complex formed. III. \[ZnS{{O}_{4}}\] and \[Ti{{O}_{2}}\] are white as in both,\[d-d\] spectra are impossible. Select the correct statements.
question_answer63) Standard enthalpy and standard entropy change for the oxidation of \[N{{H}_{3}}\] at \[298\,\,K\] are \[-382.64\,\,kJ\,\,mo{{l}^{-1}}\]and\[-145.6\,\,J\,\,mo{{l}^{-1}}\]respectively. Standard Gibbs energy change for the same reaction at \[298\,\,K\] is
question_answer64) According to the Arrhenius equation, a straight line is to be obtained by plotting the logarithm of the rate constant of a chemical reaction \[(\log k)\] against
question_answer67) The bond dissociation energies of gaseous \[{{H}_{2}},\,\,C{{l}_{2}}\] and \[HCl\] are \[104,\,\,58\] and \[103\,\,kcal\] respectively. The enthalpy of formation of \[HCl\] gas would be
question_answer70) \[Zn|Z{{n}^{2+}}(a=0.1\,\,M)||F{{e}^{2+}}(a=0.01\,\,M)|Fe.\]The emf of the above cell is\[0.2905\,\,V\]. Equilibrium constant for the cell reaction is
question_answer71) \[50\,\,mL\] of \[1\,\,M\] oxalic acid (molar mass\[=126\]) is shaken with \[0.5\,\,g\] of wood charcoal. The final concentration of the solution after adsorption is\[0.5\,\,M\]. What is the amount of oxalic acid adsorbed per gram of carbon?
question_answer72) A dust particle has mass equal to\[{{10}^{-11}}g\], diameter \[{{10}^{-4}}cm\] and velocity\[{{10}^{-4}}cm/s\]. The error in measurement of velocity is\[0.1\,\,%\]. What will be the uncertainty in its position?
question_answer84) Iron crystallises in a bcc system with a lattice parameter of\[2.861\,\,\overset{\text{o}}{\mathop{\text{A}}}\,\]. Calculate the density of iron in the bcc system (atomic weight of\[Fe=56,\,\,{{N}_{A}}=6.02\times {{10}^{23}}mo{{l}^{-1}})\].
question_answer86) The equilibrium constant for the reaction,\[{{H}_{2}}(g)+{{I}_{2}}(g)2HI(g)\]is 64. If the volume of the container is reduced to half of the original volume, the value of the equilibrium constant will be
question_answer87) For the reaction,\[Zn(s)+C{{u}^{2+}}(0.1M)\xrightarrow{{}}Z{{n}^{2+}}(1M)+Cu(s)t\]akmg 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_answer93) \[Phenol\xrightarrow[(ii)\,\,C{{O}_{2}}/{{140}^{o}}C]{(i)\,\,NaOH}A\xrightarrow{{{H}^{+}}/{{H}_{2}}O}B\xrightarrow{A{{c}_{2}}O}C\]In this reaction, the end product \['C'\] is
question_answer96) The equivalent weight of \[N{{a}_{2}}{{S}_{2}}{{O}_{3}}\] in the following reaction is \[2N{{a}_{2}}{{S}_{2}}{{O}_{3}}+{{I}_{2}}\xrightarrow{{}}N{{a}_{2}}{{S}_{4}}{{O}_{6}}+2NaI\]
question_answer97) The half-life period for first order reaction having activation energy \[39.3\,\,kcal\,\,mo{{l}^{-1}}\] at \[{{300}^{o}}C\] and frequency constant \[1.11\times {{10}^{11}}{{s}^{-1}}\] will be
question_answer98) Water is brought to boil under a pressure of\[1.0\,\,atm\]. When an electric current of \[0.50\,\,A\] from a \[12\,\,V\] supply is passed for \[300\,\,s\] through a resistance in thermal contact with it, it is found that \[0.798\,\,g\] of water is vaporised. Calculate the molar internal energy change at boiling point\[(373.15\,\,K)\].
question_answer99) The electrons, identified by quantum numbers\[n\] and\[l\], (i)\[n=4,\,\,l=1\](ii)\[n=4,\,\,l=0\] (iii)\[n=3,\,\,l=2\](iv)\[n=3,\,\,l=1\]can be placed in order of increasing energy, from the lowest to highest, as
question_answer100) At certain temperature and a total pressure of\[{{10}^{5}}\,\,Pa\], iodine vapours contains \[40%\] by volume of iodine atoms. \[{{K}_{p}}\] for the equilibrium, \[{{I}_{2}}(g)2I(g)\];will be
question_answer102) There were two women participating in a chess tournament. Every participant played two games with the other participants. The number of games that the men played between themselves proved to exceed by 66 the number of games that the men played with the women. The number of participants is
question_answer106) A student is to answer \[10\] out of \[13\] questions in an examination such that he must choose atleast \[4\] from the first five questions. The number of choices available to him is
question_answer108) The angle between the lines whose direction cosines satisfy the equations\[l+m+n=0,\,\,{{l}^{2}}+{{m}^{2}}-{{n}^{2}}=0\], is given by
question_answer109) The equation of the plane containing the line of intersection of the planes \[2x-y=0\] and \[y-3z=0\] and perpendicular to the plane \[4x+5y-3z-8=0\] is
question_answer110) If \[f(x)\] and \[g(x)\] are two functions with \[g(x)=x-\frac{1}{x}\]and \[fog(x)={{x}^{3}}-\frac{1}{{{x}^{3}}}\], then\[f'(x)\] is equal to
question_answer115) The value of \[b\] such that scalar product of the vector \[(\widehat{\mathbf{i}}+\widehat{\mathbf{j}}+\widehat{\mathbf{k}})\] with the unit vector parallel to sum of the vectors \[(2\widehat{\mathbf{i}}+4\widehat{\mathbf{j}}-5\widehat{\mathbf{k}})\] and \[(b\widehat{\mathbf{i}}+2\widehat{\mathbf{j}}+3\widehat{\mathbf{k}})\] is\[1\], is
question_answer120) The distance of the point \[(-1,\,\,5,\,\,-10)\] from the point of intersection of the line \[\frac{x-2}{3}=\frac{y+1}{4}=\frac{z-2}{12}\] and the plane\[x-y+z=5\], is
question_answer128) If the second, third and fourth terms in the expansion of \[{{(x+a)}^{n}}\] are \[240,\,\,\,720\] and \[1080\] respectively, then the value of \[n\] is
question_answer130) The value of the expression \[1\cdot (2-\omega )(2-{{\omega }^{2}})+2\cdot (3-\omega )(3-{{\omega }^{2}})+...\] \[+(n-1)(n-\omega )(n-{{\omega }^{2}})\], where \[\omega \] is an imaginary cube root of unity, is
question_answer131) If the first term of a \[GP\,\,{{\alpha }_{1}},\,\,{{\alpha }_{2}},\,\,{{\alpha }_{3}},...\]is unity such that \[4{{\alpha }_{2}}+5{{\alpha }_{3}}\] is least, then the common ratio of \[GP\] is
question_answer132) If the \[AM\] of two numbers is greater than \[GM\] of the numbers by \[2\] and the ratio of the numbers is\[4:1\], then the numbers are
question_answer143) The mean of a set of observations is\[x\]. If each observation is divided by \[\alpha ,\,\,\alpha \ne 0\] and then is increased by\[10\], then the mean of the new set is
question_answer146) The angle of elevation of the top of a tower from the top of a house is \[{{60}^{o}}\] and the angle of depression of its base is\[{{30}^{o}}\]. If the horizontal distance between the house and the tower be \[12\,\,m\], then the height of the tower is
question_answer148) If \[x\] is parallel to \[y\] and\[z\], where\[\mathbf{x}=2\widehat{\mathbf{i}}+\widehat{\mathbf{j}}+\alpha \widehat{\mathbf{k}}\],\[\mathbf{y}=\alpha \widehat{\mathbf{i}}+\widehat{\mathbf{k}}\]and\[\mathbf{z}=5\widehat{\mathbf{i}}-\widehat{\mathbf{j}}\], then a is equal to