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WT9, , [Max Marks : 50] [Allowed Time: 60 Minutes], , Important Instruction :, TT. 60min, MM. 50M, 2marks-10Q, 3marks-10Q, Section A, 1., , Two wires of same material and length are stretched by the same force., Their masses are in the ratio 3:2. Find the ratio of their elongations., , 2., , The young’s modulus of the material of a wire is 6, , 1012N/m2 and there is no, , The young’s modulus of the material of a wire is 6 x 1012 N/m2 and there is no, , 2 Mark[s], , 2 Mark[s], ( 926238 ), , transverse strain in it. Find its modulus of rigidity?, 4., , ( 501026 ), , ( 501027 ), , transverse strain in it. Find its modulus of rigidity?, 3., , 2 Mark[s], , Two wires A and B of the same material have radii in the ratio 2:1 and, , 2 Mark[s], , lengths in the ratio 4:1. Find the ratio of the normal forces required to, , ( 718039 ), , produce the same change in the lengths of the two wires?, 5., , The stress-strain graphs for materials A and B are shown in Fig. 9.12., The graphs are drawn to the same scale., , 2 Mark[s], ( 1702872 ), , (a) Which of the materials has the greater Young’s modulus?, (b) Which of the two is the stronger material?, 6., , The young’s modulus of the material of a wire is 6, , 1012N/m2 and there is no, , transverse strain in it. Find its modulus of rigidity?, 7., , Read the following two statements below carefully and state, with reasons, if it is true, or false., , 2 Mark[s], ( 718028 ), 2 Mark[s], ( 1702877 ), , (a) The Young’s modulus of rubber is greater than that of steel;, (b) The stretching of a coil is determined by its shear modulus., 8., , The ratio of radii of two wires of same material is 2:1. If these wires are, stretched by equal force, find the ratio of stresses produced in them., , 9., , A piece of copper having a rectangular cross-section of 15.2 mm × 19.1 mm is pulled, in tension with 44,500 N force, producing only elastic deformation. Calculate the, , 2 Mark[s], ( 718046 ), 2 Mark[s], ( 1702949 ), , resulting strain?, 10., , Determine the volume contraction of a solid copper cube, 10 cm on an edge, when, subjected to a hydraulic pressure of 7.0 ×106 Pa., Section B, , 2 Mark[s], ( 1703048 )

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1., , Forces of 105N each are applied in opposite directions on upper and lower, faces of a cube of side 10cm, shifting the upper face parallel to itself by, , 3 Mark[s], ( 502290 ), , 0.5cm. If the side of the cube were 20cm, what would be the displacement?, , 2., , A copper and a steel wire of same length and cross section are attached end, to end. The compound wire is hung from a rigid support and a load is, , 3 Mark[s], ( 503394 ), , suspended from the free end. If Y of steel is (20/9) times of copper then find, the ratio of increase in length of steel wire to copper wire?, 3., , A copper and a steel wire of same length and cross section are attached end, to end. The compound wire is hung from a rigid support and a load is, , 3 Mark[s], ( 718041 ), , suspended from the free end. If Y of steel is (20/9) times of copper then find, the ratio of increase in length of steel wire to copper wire?, 4., , Compute the fractional change in volume of a glass slab, when subjected to a, hydraulic pressure of 1 atm. It is given bulk modulus of glass = 37X109Nm-2, , 5., , 6., , A spherical ball contracts in volume by 0.01% when subjected to a normal, , 3 Mark[s], , uniform pressure of 100 atm. Calculate the bulk modulus of the material., , ( 718117 ), , The length of a wire increases by 8 mm when a weight of 5 kg is hung. If the, radius of the wire is doubled, what will be the increase in length?, , 7., , A long spring is stretched by 2 cm and its potential energy is V. Find the, potential energy of the spring if it is stretched by 10 cm?, , 8., , 3 Mark[s], ( 718115 ), , A steel wire of length 4.7 m and cross-sectional area 3.0 × 10–5 m 2 stretches by the, same amount as a copper wire of length 3.5 m and cross-sectional area of 4.0 × 10–5, , 3 Mark[s], ( 503402 ), 3 Mark[s], ( 502261 ), 3 Mark[s], ( 1702849 ), , m 2 under a given load. What is the ratio of the Young’s modulus of steel to that of, copper?, 9., , Define the following terms:, (i) Gravitational Force, , 3 Mark[s], ( 925795 ), , (ii) Strong Nuclear Force, (iii) Weak Nuclear Force, 10., , A 14.5 kg mass, fastened to the end of a steel wire of unstretched length 1.0 m, is, , 3 Mark[s], , whirled in a vertical circle with an angular velocity of 2 rev s-1 at the bottom of the, , ( 1702980 ), , circle. The cross-sectional area of the wire is 0.065 cm2 . Calculate the elongation of, the wire when the mass is at the lowest point of its path.