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CH-9 & 10, Mechanical properties of Solids & fluids, Q1. A wire is stretched to double its length. What is the value of, longitudinal strain?, Q2. Write copper, steel, glass, and rubber in the order of increasing, coefficient of elasticity., Q3. (i) What is Poisson’s ratio?, (ii) Define elastic fatigue., (iii) Define elastic after effect., Q4. (I) Define modulus of rigidity., (ii) Define compressibility., (iii) Define Young’s modulus., Q5. Define tensor physical quantities. Give an example., Q6. (I) Define longitudinal strain., (ii) Define volumetric strain., (iii)Define shear strain., (iv) State Hook’s law., Q7. A mass of 5 kg is hung from a copper wire of 1 mm diameter and, 2 m in length. Calculate the extension produced. What should be the, minimum diameter of the wire so that its elastic limit is not exceeded?, Elastic limit for copper = 1.5 × 109 dyne cm-2, Y for copper = 1.1 × 1012, dyne cm-2

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Q8. Surface tension of a soap solution is 1.9 × 10-2N/m. work done in, blowing a bubble of 2.0 cm diameter will be?, Q9. Plants get water through the roots because of, (a) Capillarity, (b) Viscosity, (c) Gravity, (d) Elasticity, Q10. Water rises up to a height of 5 cm in a capillary tube of radius 2, mm. what is the radius of the capillary tube if the water rises up to a, height of 10 cm in another capillary?, Q11. (a) Define critical velocity., (b) What is Reynolds number?, Q12. State Pascal’s law. How does it get changed in the presence of, gravity?, Q13. Stoke’s law deals with spherical bodies moving through a, viscous fluid. Give its statement and derive it dimensionally., Q14. (a) Derive the expression for excess pressure inside:, (i) a liquid drop., (ii) a liquid bubble., (iii) an air bubble., (b) Derive the expression for terminal velocity.