question_answer2) A body of mass m is moving in a circle of radius r with a constant speed \[\upsilon \]. If a force \[\frac{m{{v}^{2}}}{r}\] is acting on the body towards the centre, then what will be the work done by this force in moving the body over half the circumference of the circle?
question_answer3) If under the action of a force \[(4i+j+3k)\,N\], a particle moves from position \[{{r}_{1}}=3i+2j-6k\] to position \[{{r}_{2}}=14i+13j+9k\], then the work done will be
question_answer4) A particle of mass m moving with velocity u makes an elastic one dimensional collision with a stationary particle of mass m. They are in contact for a short time T. Their force of interaction increases from zero to \[{{F}_{0}}\] linearly in time \[\frac{T}{2}\] and decreases linearly to zero in further time \[\frac{T}{2}\] (shown in figure). The magnitude of \[{{F}_{0}}\] is
question_answer5) Two planets revolves around the sun with frequencies \[{{N}_{1}}\] and \[{{N}_{2}}\] revolutions per year. If their average radii (orbital) be \[{{R}_{1}}\] and \[{{R}_{2}}\] respectively, then \[{{R}_{1}}/{{R}_{2}}\] is equal to
question_answer6) To what height water should be filled in a container of height 21 cm, so that it appears as half filled when viewed from the top \[\left( Tak{{e}_{a}}{{\mu }_{w}}=\frac{4}{3} \right)\]
question_answer7) A progressive wave is represented as \[y=0.2\cos \pi \left( 0.04+0.2x-\frac{\pi }{6} \right)\] where distance is expressed in cm and time in second. What will be the minimum distance between two particles having the phase difference of \[\frac{\pi }{2}\]?
question_answer9) The distance between the poles of a horse shoe magnet is 0.1 m and its pole strength is 0.01 A-m. The induction of magnetic field at a point mid way between the poles will be
question_answer11) For the transistor circuit shown in figure, if\[\beta =100\], voltage drop across emitter and base is 0.7 V, then the value of \[{{V}_{CE}}\] will be
question_answer12) If a uniform solid sphere and a disc of same mass and same radius rolls down on an inclined smooth plane from rest to the same distance, then the ratio of the time taken by them will be
question_answer13) If a stone is projected from ground with a velocity \[50\,m{{s}^{-1}}\] and at an angle of \[{{30}^{o}}\], it takes 3 s to cross a wall. How far beyond the wall the stone will strike the ground? (Take \[g=10\,\,m{{s}^{-2}}\])
question_answer14) For a body starting from rest, what will be the ratio of the distance travelled by the body during the 4th and 3rd second during its journey?
question_answer15) If the compressibility of water is a (sigma) per unit atmospheric pressure, then the decrease in volume V due to p, atmospheric pressure will be
question_answer16) A soap film of surface tension \[3\times {{10}^{-2}}N{{m}^{-1}}\] formed in a rectangular frame, can support a straw. If the length of the film is 10 cm, then the mass of the straw that film can support is
question_answer17) There are two identical small holes of area of cross section a on the either sides of a tank containing a liquid of density \[\rho \] (shown in figure). The difference in height between the holes is ft. Tank is resting on a smooth horizontal surface. Horizontal force which will has to be applied on the tank to keep it in equilibrium is
question_answer18) Certain amount of an ideal gas of molecular mass M is contained in a closed vessel. If the vessel is moving with a constant velocity v, then the rise in temperature of the gas when the vessel is suddenly stopped will be \[\left( Take\,\,\gamma =\frac{{{C}_{p}}}{{{C}_{V}}} \right)\]
question_answer19) Water and turpentine oil (specific heat less than that of water) are both heated to same temperature. Equal amounts of both are then placed in identical calorimeters and then left in air
A)
A and B will represent cooling curves of water and oil respectively
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B)
B and A will represent cooling curves of water and oil respectively
question_answer20) By suspending a mass of 0.50 kg a spring is stretched by 8.20 m. If a mass of 0.25 kg is suspended, then its period of oscillation will be (Take \[g=10\,\,m{{s}^{-2}}\])
question_answer21) If the period of revolution of a nearest satellite around a planet of radius R is T then its period of revolution around another planet, having radius 3JR and same density will be
question_answer22) A body of mass m is suspended from a string of length \[l\]. What is the minimum horizontal velocity that should be given to the body at its lowest position so that it may complete one full revolution in the vertical plane with the point of suspension as the centre of the circle?
question_answer24) Which one of the following graphs represents the graph between the instantaneous concentration (N) of a radioactive element and time (t)?
question_answer26) In a diode AM detector, the output circuit consists of \[R=1\,k\Omega \] and \[C=10\,pF\]. A carrier signal of 100 k Hz is to be detected. Is it good?
question_answer27) Let a straight wire of length I carries a current\[i\]. The magnitude of magnetic field produced by the current at point P (as shown in figure) is
question_answer28) 0.8 J work is done in rotating a magnet by \[{{60}^{o}}\], placed parallel to a uniform magnetic field. How much work is done in rotating it \[{{30}^{o}}\]further?
question_answer29) The magnetic moment produced in a substance of 1 g is \[6\times {{10}^{-7}}\,\,A-{{m}^{2}}\]. If its density is \[5\,g\,c{{m}^{-3}}\], then the intensity of magnetisation in A/m will be
question_answer31) Let ABC is a right angled triangle in which AB = 3 cm and BC = 4 cm and \[\angle ABC={{90}^{o}}\]. The three charges +15, +12 and -20 esu are placed on 4, B and C respectively. The force acting on B will be
question_answer32) Four plates of same area of cross-section are joined as shown in figure. The distance between each plate is d. The equivalent capacity between A and B will be
question_answer33) If a voltmeter of resistance 1000 \[\Omega \] is connected across a resistance of 500 \[\Omega \] in the given circuit, then the reading of voltmeter will be
question_answer34) In the grid circuit of a triode a signal \[E=2\sqrt{2}\cos \,\omega t\] is applied. If \[\mu =14\] and\[{{r}_{p}}=10\,\,k\Omega \], then rms current flowing through \[{{R}_{L}}=12\,k\Omega \] will be
question_answer35) A rigid body of mass m rotates with angular velocity g) about an axis at a distance a from the centre of mass C. The radius of gyration about C is K. Then, kinetic energy of rotation of the body about new parallel axis is
question_answer36) The angle of contact between glass and water is \[{{0}^{o}}\] and it rises in a capillary upto 6 cm when its surface tension is 70 dyne/cm. Another liquid of surface tension 140 dyne/cm, angle of contact \[{{60}^{o}}\] and relative density 2 will rise in the same capillary by
question_answer37) If the height of a mercury barometer is 75 cm at sea level and 50 cm at the top of a hill and the ratio of density of mercury to that of air is \[{{10}^{4}}\] then the height of the hill is
question_answer38) If the displacement equation of a particle from its mean position is given as \[y=0.2\sin \,(10\pi t+1.5\pi )cos(10\pi t+1.5\pi )\] then, the motion of particle is
question_answer39) Let PQR is a right angled prism with other angles as \[{{60}^{o}}\] and \[{{30}^{o}}\]. PQ has a thin layer of liquid and light falls normally oh the face PR as shown in figure. If the refractive index of prism is 1.5, then for total internal reflection, maximum refractive index of liquid will be
question_answer42) A resistor R, inductor L and a capacitor C are connected in series to an oscillator of frequency v. If the resonant frequency is \[{{v}_{r}}\], theft the current lags behind the voltage, when
question_answer43) The instantaneous values of current and voltage in an AC circuit are \[i=100\sin 314t\] amp and \[e=200\sin \left( 314t+\frac{\pi }{3} \right)V\] respectively. If the resistance is \[1\,\Omega \], then the reactance of the circuit will be
question_answer44) When green light is incident on the surface of a metal. It emits photo electrons but there is no such emission with yellow colour light. Which one of the colour can produce emission of photo electrons?
question_answer45) If an electron jumps from the 4th orbit to the 2nd orbit of hydrogen atom, then the frequency of emitted radiation in the hertz will be (Take Rydbergs constant, \[R={{10}^{5}}\,c{{m}^{-1}}\])
question_answer46) If the ratio of radii of nuclei \[_{13}^{27}\]Al and \[_{52}^{A}X\] is 3 : 5, then the number of neutrons in the nuclei of X will be
question_answer47) Number of nuclei of a radioactive substance at time t = 0 are 1000 and 900 at time t = 2 s. What will be the number of nuclei at time t = 4 s?
question_answer48) A bar magnet has coercivity \[4\times {{10}^{3}}A{{m}^{-1}}\]. It is desired to demagnetise it by inserting it inside a solenoid 12 cm long and having 60 turns. The current that should be sent through the solenoid is
question_answer51) When 1 mole gas is heated at constant volume, temperature is raised from 298 K to 308K. Heat supplied to the gas is 500 J. Then which statement is correct?
question_answer52) For the reaction, \[2{{N}_{2}}{{O}_{5}}\to 4N{{O}_{2}}+{{O}_{2}}\] rate and rate constant are \[1.02\times {{10}^{-4}}\] and\[3.4\times {{10}^{-5}}{{s}^{-1}}\] respectively, then concentration of \[{{N}_{2}}{{O}_{5}}\] at that time will be
question_answer53) A human body required the 0.01 M activity of radioactive substance after 24 h. Half-life of radioactive substanu is 6 h. Then injection of maximum activity of radioactive substance that can be injected
question_answer57) A compound formed by elements A and B crystallises in the cubic structure where A atoms are at the corners of a cube and B atoms are at the face centres. The formula of the compound is
question_answer58) Assuming fully decomposed, the volume of\[C{{O}_{2}}\] released at STP on heating 9.85 g of \[BaC{{O}_{3}}\] (atomic mass, Ba = 137) will be
question_answer61) \[_{92}{{U}^{235}}\] nucleus absorbs a neutron and disintegrate in \[_{54}X{{e}^{139}},\,{{\,}_{38}}S{{r}^{94}}\] and X so, what will be product X?
question_answer64) Solution of \[0.1\,N\,N{{H}_{4}}OH\] and \[0.1\,N\,N{{H}_{4}}Cl\] has \[pH\,9.25\], then find out \[p{{K}_{b}}\] of \[N{{H}_{4}}OH\].
question_answer68) In electrolysis of \[NaCl\] when Pt electrode is taken then \[{{H}_{2}}\] is liberated at cathode while with Hg cathode it forms sodium amalgam because
A)
Hg is more inert than Pt
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B)
more voltage is required to reduce H+ at Hg than at Pt
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C)
Na is dissolved in Hg while it does not dissolved in Pt
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D)
concentration of \[{{H}^{+}}\] ions is larger when Pt electrode is taken
question_answer70) An atom has electronic configuration\[1{{s}^{2}},2{{s}^{2}}2{{p}^{6}},3{{s}^{2}}3{{p}^{6}}3{{d}^{3}},4{{s}^{2}}\]. You will place it in
question_answer73) \[CuS{{O}_{4}}\] when reacts with KCN forms CuCN which is insoluble in water. It is soluble in excess of KCN due to the formation of the following complex
question_answer78) In the following reaction, product P is \[R-\underset{\begin{smallmatrix} || \\ O \end{smallmatrix}}{\mathop{C}}\,-Cl\xrightarrow[Pd-BaS{{O}_{4}}]{{{H}_{2}}}P\]
question_answer93) The reaction, \[C{{H}_{3}}-\overset{\begin{smallmatrix} C{{H}_{3}} \\ | \end{smallmatrix}}{\mathop{C}}\,H-C{{H}_{2}}-O-C{{H}_{2}}C{{H}_{3}}\] \[+HI\xrightarrow{\Delta }\]? Which of the following compound will be formed?
question_answer94) Predict the product C obtained in the following reaction of butyne -1. \[C{{H}_{3}}C{{H}_{2}}-C\equiv CH+HCl\xrightarrow{{}}B\xrightarrow{HI}C\]
question_answer95) Sulphide ores of metals are usually concentrated by froth floatation process. Which one of the following sulphide ores offers an exception and is concentrated by chemical leaching?
question_answer96) The equilibrium constant of the reaction; \[Cu(s)+2A{{g}^{+}}(aq)\xrightarrow{{}}C{{u}^{2+}}(aq)+2Ag(s)\]\[{{E}^{o}}=0.46\,V\]at 298 K
question_answer100) Change in enthalpy for the reaction, \[2{{H}_{2}}{{O}_{2}}(l)\xrightarrow{{}}2{{H}_{2}}O(l)+{{O}_{2}}(g)\] if heat of formation of \[{{H}_{2}}{{O}_{2}}(l)\] and \[{{H}_{2}}O(l)\]are - 188 and -286 kJ/mol respectively is
question_answer113) In a plant, the peduncle is elongated and it bears pedicillate flowers. The older flowerslie towards the base and the younger ones near the apex. The growth of the peduncle continues and more flowers are added. The inflorescence is
A species which adds up to only a small proportion of the total biomass of a community, yet has a huge impact on the communitys organization and survival
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B)
A common species that has plenty of biomass, yet has a fairly low impact on the communitys organization
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C)
A rare species that has minimal impact on the biomass and on other species in the community
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D)
A dominant species that constitutes a large proportion of the biomass and which affects many other species