• 1. 
    A body of mass 1 kg is attached to one end of a wire and rotated in horizontal circle of diameter 40 cm with a constant speed of 2 m/s. what is the area of cross-section of the wire if the stress developed in the wire is 5 × 106 N/m²?

  • 2 mm²
  • 3 mm²
  • 4 mm²
  • 5 mm²
  • 2. 
    In a wire, when elongation is 2 cm energy stored is E. if it is stretched by 10 cm, then the energy stored will be

  • E
  • 2 E
  • 4 E
  • 25 E
  • 3. 
    Two wires A and B are of the same length. The diameters are in the ratio 1 : 2 and the Youngs modulus are in ratio 2 : 1. if they are pulled by the same force, then their elongations will be in ratio

  • 4 : 1
  • 1 : 4
  • 1 : 2
  • 2 : 1
  • 4. 
    Hookes law essentially defines

  • Stress
  • Strain
  • Yield point
  • Elastic limit
  • 5. 
    Longitudinal strain is possible in the case of

  • Gases
  • Liquid
  • Only solids
  • Only gases & liquids
  • 6. 
    Two wires have the same material and length, but their masses are in the ration of 4 : 3. If they are stretched by the same force, their elongations will be in the ratio of

  • 2 : 3
  • 3 : 4
  • 4 : 3
  • 9 : 16
  • 7. 
    A rubber cord of cross sectional area 1 mm² and unstretched length 10 cm is stretched to 12 cm and then released to project a stone of mass 5 gram. If Y for rubber = 5 ? 108N/m², then the tension in the rubber cord is

  • 25 N
  • 50 N
  • 100 N
  • 200 N
  • 8. 
    Out of the following materials, whose elasticity is independent of temperature?

  • Copper
  • Invar steel
  • Brass
  • Silver
  • 9. 
    An iron bar of length l m and cross section A m² is pulled by a force of F Newton from both ends so as to produce and elongation in meters. Which of the following statement statements is correct

  • Elongation is inversely proportional to length l
  • Elongation is directly proportional to cross section A
  • Elongation is inversely proportional to A
  • Elongation is directly proportional to Youngs modulus
  • 10. 
    The ratio of the change in dimension at right angles to the applied force to the initial dimension is known as

  • Youngs modulus
  • Poissons ratio
  • Lateral strain
  • Shearing strain
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