May 2011 - Career Point

dxO12. The time of crossing the river is -(A) (d) 1/3 (B) (6d) 1/3(C) (2d) 1/3(D) None of these13. The drift of the swimmer is -(A) v 0 (d) 1/3 (B) v 0 (2d) 1/3(C) v 0 (6d) 1/3 (D) None of thesey14. The equation of trajectory of the path followed bythe swimmer -2xx(A) y =(B) y =v202v(C) y =x6v330v 0(D) None of thesePassage : II (Q. No. 15 to 16)A metal ring having three metallic spokes of lengthr = 0.2 m is in vertical plane and can spin around afixed horizontal axis in a homogeneous magneticfield of a magnetic induction B = 0.5 T. The linesof magnetic field are perpendicular to the plane ofmetal ring. Between the axis of the metal ring andits perimeter we connect a consumer of resistanceof 0.15 Ω with the help of two sliding contact. Wefix a thread of negligible mass to the rim of the ringand wind it several times around the ring and to itsend we fix a body of a mass of 20 g. At a givenmoment we release the body of mass m. the frictionis negligible everywhere, the resistance of the ring,the spokes and the connected wiring is alsonegligible.15. What is the torque exerted on the ring with spokesby the magnetic force when the body of mass m ismoving with a constant velocity -0B16. What current is flowing through the consumerwhen the velocity of the body of mass m is 3m/s -(A) 1 Amp(B) 3 Amp(C) 2 Amp(D) 4 AmpThis section contains 7 questions (Q.17 to 23).+4 marks will be given for each correct answer andno negative marking. The answer to each of thequestions is a SINGLE-DIGIT INTEGER, rangingfrom 0 to 9. The appropriate bubbles below therespective question numbers in the OMR have to bedarkened. For example, if the correct answers toquestion numbers X, Y, Z and W (say) are 6, 0, 9 and2, respectively, then the correct darkening of bubbleswill look like the following :X Y Z W0123456789012345678917. The speed of a motor launch with respect to theflow of water in stream was v = 7 m/s, the speed ofthe stream was u = 3 m/s. When the launch begantraveling upstream, a float was dropped from it.The launch traveled l = 4.2 km upstream, turnedabout and caught up with the float. How long wasit before the launch reached the float (Answer in................× 10 1 minutes)18. A man is running with a speed 8 m/s constant inmagnitude and direction passes under a lanternhanging at a height 10 m above the ground. Findthe velocity which the edge of the shadow of theman's head moves over the ground with if hasheight is 2 m. (Answer in ............ × 10 1 m/sec)19. Two motor vehicles run at constant speeds 5 m/seach along highways intersecting at an angle 60º.In what time after they meet at the intersection willthe distance between the vehicles be 10 3 m.01234567890123456789(A) 0.02 N-m(C) 0.06 N-mm(B) 0.04 N-m(D) 0.08 N-m20. A boy is standing on an open truck. Truck ismoving with an acceleration 2m/s 2 on horizontalroad. When speed of truck is 10 m/s, boy projecteda ball with velocity 10 m/s in vertical upwarddirection relative to himself (take g = 10 m/s 2 ).After how many seconds of projection of ball, ballis moving backward horizontally as seen by boy.XtraEdge for IIT-JEE 48 MAY 2011