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JEE Main (Apr 09) CBT | 2017
Q. For the P-V diagram given for an ideal gas, out of the following which one correctly represents the T-P diagram?
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Q. A negative test charge is moving near a long straight wire carrying a current. The force acting on the test charge is parallel to the direction of the current. The motion of the charge is :
  1. Towards the wire
  2. Away from the wire
  3. Parallel to the wire along the current
  4. Parallel to the wire opposite to the current
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Q. The electric field component of a monochromatic radiation is given by
E=2E0^icoskz cosωt
Its magnetic field B is then given by :
  1. 2E0c^jsinkzcosωt
  2. 2E0c^jsinkzsinωt
  3. 2E0c^jcoskzcosωt
  4. 2E0c^jsinkzsinωt
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Q. The current gain of a common emitter amplifier is 69. If the emitter current is 7.0mA, collector current is:
  1. 9.6mA
  2. 0.69mA
  3. 6.9mA
  4. 69mA
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Q. In an experiment to determine the period of a simple pendulum of length 1m, it is attached to different spherical bobs of radii r1 and r2. The two spherical bobs have uniform mass distribution. If the relative difference in the periods, is found to be 5×104s, the difference in radii, |r1r2| is best given by :
  1. 1cm
  2. 0.01cm
  3. 0.1cm
  4. 0.5cm
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Q. N moles of a diatomic gas in a cylinder are at a temperature T. Heat is supplied to the cylinder such that the temperature remains constant but n moles of the diatomic gas gets converted into monatomic gas. What is the change in the total kinetic energy of the gas ?
  1. 52nRT
  2. 12nRT
  3. 0
  4. 32nRT
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Q. A uniform wire of length l and radius r has a resistance of 100Ω. It is recast into a wire of radius r2. The resistance of new 2 wire will be :
  1. 100Ω
  2. 1600Ω
  3. 200Ω
  4. 400Ω
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Q. In an experiment a convex lens of focal length 15cm is placed coaxially on an optical bench in front of a convex mirror at a distance of 5cm from it. It is found that an object and its image coincide, if the object is placed at a distance of 20cm from the lens. The focal length of the convex mirror is:
  1. 27.5cm
  2. 25.0cm
  3. 30.5cm
  4. 20.0cm
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Q. The mass density of a spherical body is given by ρ(r)=kr for rR and ρ(r)=0 for r>R, where r is the distance from the centre. The correct graph that describes qualitatively the acceleration, a, of a test particle as a function of r is :
  1. 629702_2133417_1428db7bb4ac4feba83f1da628b42614.png
  2. 629702_2133418_48aea22db070419d874896e9da632f37.png
  3. 629702_2133419_35022c08caf64e1e921d44c6a34f79cb.png
  4. 629702_2133420_a5d2abf641a94f1bb1580bd07d3b6459.png
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Q. A standing wave is formed by the superposition of two waves travelling in opposite directions. The transverse displacement is given by
y(x, t)=0.5sin(5π4x)cos(200πt).
What is the speed of the travelling wave moving in the positive x direction ?
(x and t are in meter and second, respectively.)
  1. 90m/s
  2. 180m/s
  3. 120m/s
  4. 160m/s
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Q. Four closed surface and corresponding charges distributions are shown below:
Let the respective electric fluxes through the surfaces be Φ1, Φ2, Φ3 and Φ4. Then :
629666_4ae377490a944fedaac138d6c35a74f8.png
  1. Φ1>Φ3;Φ2<Φ4
  2. Φ1<Φ2=Φ3>Φ4
  3. Φ1>Φ2>Φ3>Φ4
  4. Φ1=Φ2=Φ3=Φ4
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Q. A circular hole of radius R4 is made in a thin uniform disc having mass M and radius R, as shown in figure. The moment of inertia of the remaining portion of the disc about an axis passing through the point O and perpendicular to the plane of the disc is :
629661_5eaa316059794898942089ca9b765986.png
  1. 197MR2256
  2. 219MR2256
  3. 237MR2512
  4. 19MR2512
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Q. Two tubes of radii r1 and r2, and lengths l1 and l2, respectively, are connected in series and a liquid flows through each of them in stream line conditions. P1 and P2 are pressure differences across the two tubes. If P2 is 4P1 and l2 is l14, then the radius r2 will be equal to :
  1. 2r1
  2. 4r1
  3. r1
  4. r12
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Q. A Laser light of wavelength 660nm is used to weld Retina detachment. If a Laser pulse of width 60ms and power 0.5kW is used, the approximate number of photons in the pulse are:
[Take Planck's constant h=6.62×1034Js]
  1. 1022
  2. 1019
  3. 1020
  4. 1018
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Q. In a meter bridge experiment resistances are connected as shown in the figure. Initially resistance P=4Ω and the neutral point N is at 60cm from A. Now an unknown resistance R is connected in series to P and the new position of the neutral point is at 80cm from A. The value of unknown resistance R is :
629697_fe18b696d49840a395c078f9f6480151.png
  1. 7Ω
  2. 203Ω
  3. 6Ω
  4. 335Ω
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Q. A sinusoidal voltage of peak value 283V and angular frequency 320/s is applied to a series LCR circuit. Given that R=5Ω, L=25mH and C=1000μF. The total impedance, and phase difference between the voltage across the source and the current will respectively be:
  1. 7Ω and 45o
  2. 10Ω and tan1(83)
  3. 10Ω and tan1(53)
  4. 7Ω and tan1(53)
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Q. The machine as shown has 2 rods of length 1m connected by a pivot at the top. The end of one rod is connected to the floor by a stationary pivot and the end of the other rod has a roller that rolls along the floor in a slot. As the roller goes back and forth, a 2kg weight moves up and down. If the roller is moving towards right at a constant speed, the weight moves up with a :
629659_1e8ac62b562b4b3ea30f7c402fe6260a.png
  1. Increasing speed speed which is 34th of the
  2. Roller when weight is 0.4m above the ground
  3. Constant speed
  4. Decreasing speed
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Q. Imagine that a reactor converts all given mass into energy and that it operates at a power level of 109W. The mass of the fuel consumed per hour in the reactor will be (velocity of light, c is 3×108m/s)
  1. 0.8gm
  2. 0.96gm
  3. 4×102gm
  4. 6.6×105gm
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Q. A car is standing 200m behind a bus, which is also at rest. The two start moving at the same instant but with different forward accelerations. The bus has acceleration 2m/s2 and the car has acceleration 4m/s2. The car will catch up with the bus after a time of :
  1. 102s
  2. 110s
  3. 120s
  4. 15s
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Q. A signal is to be transmitted through a wave of wavelength λ, using a linear antenna. The length l of the antenna and effective power radiated Peff will be given respectively as :
(K is a constant of proportionality)

  1. λ16, Peff=K(1λ)3
  2. λ5, Peff=K(1λ)12
  3. λ8, Peff=K(1λ)
  4. λ, Peff=K(1λ)2
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Q. Two particles A and B of equal mass M are moving with the same speed υ as shown in the figure. They collide completely inelastically and move as a single particle C. The angle θ that the path of C makes with the X-axis is given by :
629693_654ad409792242fba4c02574f6d023ce.png
  1. tanθ=3+212
  2. tanθ=122(1+3)
  3. tanθ=131+2
  4. tanθ=3212
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Q. A combination of parallel plate capacitors is maintained at a certain potential difference. When a 3mm thick slab is introduced between all the plates, in order to maintain the same potential difference, the distance between the plates is increased by 2.4mm. Find the dielectric constant of the slab.
629695_ad53732f811b4258b9979c20374bbd41.png
  1. 4
  2. 5
  3. 6
  4. 3
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Q. The acceleration of an electron in the first orbit of the hydrogen atom (n=1) is :
  1. h2π2m2r3
  2. h28π2m2r3
  3. 2π2kme2Zηh
  4. h24πm2r3
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Q. A block of mass 0.1kg is connected to an elastic spring of spring constant 640Nm1 and oscillates in a damping medium of damping constant 102kgs1. The system dissipates its energy gradually. The time taken for its mechanical energy of vibration to drop to half of its initial value, is closest to:
  1. 7s
  2. 5s
  3. 3.5s
  4. 2s
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Q. A uniform magnetic field B of 0.3T is along the positive Z-direction. A rectangular loop (abed) of sides 10cm×5cm carries a current I of 12A. Out of the following different orientations which one corresponds to stable equilibrium ?

  1. 629696_2133393_2cd0c153e0154932b255c9e781998740.png
  2. 629696_2133394_0ef6ccc7cf9b4d3e9916bafd237c1ba7.png
  3. 629696_2133395_842720e0955a4f3a8f15de07d8164731.png
  4. 629696_2133396_50f67de23caa411aad3eb1182d932657.png
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Q. The figure shows three circuits I, II and III which are connected to a 3V battery. If the powers dissipated by the configurations I, II and III are P1, P2 and P3 respectively, then :
629670_327e1bf247e94af19f94a374d2b6ba84.png
  1. P2>P1>P3
  2. P1>P3>P2
  3. P1>P2>P3
  4. P3>P2>P1
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Q. A single slit of width 0.1mm is illuminated by a parallel beam of light of wavelength 6000˚A and diffraction bands are observed on a screen 0.5m from the slit. The distance of the third dark band from the central bright band is :
  1. 3mm
  2. 4.5mm
  3. 1.5mm
  4. 9mm
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Q. A conical pendulum of length 1 m makes an angle θ=45o w.r.t. Z-axis and moves in a circle in the XY plane. The radius of the circle is 0.4 m and its center is vertically below O. The speed of the pendulum, in its circular path, will be : (Take g=10ms2)
629699_0106fbab654543ae98cdde6463cda7cb.png
  1. 0.4 m/s
  2. 4m/s
  3. 2 m/s
  4. 0.2 m/s
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Q. A steel rail of length 5 m and area of cross section 40cm2 is prevented from expanding along its length while the temperature rises by 10oC. If coefficient of linear expansion and Young's modulus of steel are 1.2×105K1 and 2×1011Nm2 respectively, the force developed in the rail is approximately :
  1. 2×107N
  2. 3×105N
  3. 1×105N
  4. 2×109N
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Q. A physical quantity P is described by the relation p=a1/2b2c3d4
If the relative errors in the measurement of a, b, c and d respectively, are 2, 1, 3 and 5, then the relative error in P will be :

  1. 8%
  2. 25%
  3. 12%
  4. 32%
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