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JEE Main (Apr 09) - Afternoon Shift | 2019
Q. Two coils 'P' and 'Q' are separated by some distance. When a current of 3 A flows through coil 'P', a magnetic flux of 103 Wb passes through 'Q'. No current is passed through 'Q'. When no current passes through 'P' and a current of 2A passes through 'Q', the flux through 'P' is?
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    Q. A metal wire of resistance 3Ω is elongated to make a uniform wire of double its previous length. This new wire is now bent and the ends joined to make a circle. If two points on this circle make an angle 60o at the centre, the equivalent resistance between these two points will be?
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      Q. The resistance of a galvanometer is 50 ohm and the maximum current which can be passed through it is 0.002A. What resistance must be connected to it in order to convert it into an ammeter of range 00.5A?
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        Q. The position of a particle as a function of time t, is given by x(t)=at+bt2ct3 where a, b and c are constants. When the particle attains zero acceleration, then its velocity will be?
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          Q. A thin convex lens L(refractive index =1.5) is placed on a plane mirror M. When a pin is placed at A, such that OA=18cm, its real inverted image is formed at A itself, as shown in figure. When a liquid of refractive index μ1 is put between the lens and the mirror. The pin has to be moved to A', such that OA=27cm, to get its inverted real image at A' itself. The value of μ1 will be?
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            Q. A moving coil galvanometer has a coil with 175 turns and area 1cm2. It uses a torsion band of torsion constant 106 N-m/rad. The coil is placed in a magnetic field B parallel to its plane. The coil deflects by 1o for a current of 1 mA. The value of B(in Telsa) is approximately.
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              Q. A very long solenoid of radius R is carrying current I(t)=kteαt(k>0), as a function of time (t0). counter clockwise current is taken to be positive. A circular conducting coil of radius 2R is placed in the equatorial plane of the solenoid and concentric with the solenoid. The current induced in the outer coil is correctly depicted, as a function of time, by?
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                Q. A massless spring (k=800N/m), attached with a mass (500g) is completely immersed in 1 kg of water. The spring is stretched by 2cm and released so that it starts vibrating. What would be the order of magnitude of the change in the temperature of water when the vibrations stop completely? (Assume that the water container and spring receive negligible heat and specific heat of mass =400 J/kg K, specific heat of water =4184 J/kg K)
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                  Q. A particle 'P' is formed due to a completely inelastic collision of particles 'x' and 'y' having de-Broglie wavelengths λx and λy respectively. If x and y were moving in opposite directions, then the de-Broglie wavelength of 'P' is?
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                    Q. A convex lens of focal length 20 cm produces images of the same magnification 2 when an object is kept at two distances x1 and x2 (x1>x2) from the lens. The ratio of x1 and x2 is?
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                      Q. Diameter of the objective lens of a telescope is 250cm. For light of wavelength 600nm. coming from a distant object, the limit of resolution of the telescope is close to?
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                        Q. Moment of inertia of a body about a given axis is 1.5kg m2. Initially the body is at rest. In order to produce a rotational kinetic energy of 1200J, the angular acceleration of 20 rad/s2 must be applied about the axis for a duration of?
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                          Q. The logic gate equivalent to the given logic circuit is?
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                            Q. 50W/m2 energy density of sunlight is normally incident on the surface of a solar panel. Some part of incident energy (25%) is reflected from the surface and the rest is absorbed. The force exerted on 1m2 surface area will be close to? (c=3×108m/s)
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                              Q. The area of a square is 5.29cm2. The area of 7 such squares taking into account the significant figures is?
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                                Q. The physical sizes of the transmitter and receiver antenna in a communication system are?
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                                  Q. Four point charges q, +q, +q and q are placed on y-axis at y=2d, y=d, y=+d and y=+2d, respectively. The magnitude of the electric field E at a point on the x-axis at x=D, with D >>d, will behave as?
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                                    Q. The specific heats, CP and CV of a gas of diatomic molecules, A, are given(in units of J mol1K1) by 29 and 22, respectively. Another gas of diatomic molecules, B, has the corresponding values 30 and 21. If they are treated as ideal gases, then?
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                                      Q. The position vector of a particle changes with time according to the relation r(t)=15t2^i+(420t2)^j. What is the magnitude of the acceleration at t=1?
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                                        Q. A test particle is moving in a circular orbit in the gravitational field produced by a mass density ρ(r)=Kr2. Identify the correct relation between the radius R of the particle's orbit and its period T.
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                                          Q. A particle of mass 'm' is moving with speed 2v and collides with a mass 2m moving with speed 'v' in the same direction. After collision, the first mass in stopped completely while the second one splits into two particles each of mass 'm', which move at angle 45o with respect to the original direction. The speed of each of the moving particle will be?
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                                            Q. A wooden block floating in a bucket of water has 45 of its volume submerged. When certain amount of an oil is poured into the bucket, it is found that the block is just under the oil surface with half of its volume under water and half in oil. The density of oil relative to that of water is?
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                                              Q. Two cars A and B are moving away from each other in opposite directions. Both the cars are moving with a speed of 20 ms1 with respect to the ground. If an observer in car A detects a frequency 2000 Hz of the sound coming from car B, what is the natural frequency of the sound source in car B? (speed of sound in air =340ms1)
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                                                Q. A wedge of mass M=4m lies on a frictionless plane. A particle of mass m approaches the wedge with speed v. There is no friction between the particle and the plane or between the particle and the wedge. The maximum height climbed by the particle on the wedge is given by?
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                                                  Q. A He+ ion is in its first excited state. Its ionization energy is?
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                                                    Q. Two materials having coefficients of thermal conductivity 3K and K and thickness 'd' and 3d, respectively, are joined to form a slab as shown in the figure. The temperature of the outer surfaces are θ2 and θ1 respectively, (θ2>θ1). The temperature at the interface is?
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                                                      Q. A thin smooth rod of length L and mass M is rotating freely with angular speed ω0 about an axis perpendicular to the rod and passing through its center. Two beads of mass m and negligible size are at the center of the rod initially. The beads are free to slide along the rod. The angular speed of the system, when the beads reach the opposite ends of the rod, will be?
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                                                        Q. The parallel combination of two air filled parallel plate capacitors of capacitance C and NC is connected to a battery of voltage, V. When the capacitors are fully charged, the battery is removed and after that a dielectric material of dielectric constant K is placed between the two plates of the first capacitor. The new potential difference of the combined system is?
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                                                          Q. In a conductor, if the number of conduction electrons per unit volume is 8.5×1028m3 and mean free time is 25fs (femto second), it's approximate resistivity is?(me=9.1×1031kg)
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                                                            Q. A string 2.0m long and fixed at its ends is driven by a 240 Hz vibrator. The string vibrates in its third harmonic mode. The speed of the wave and its fundamental frequency is?
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