Physics-I question paper (PHY 101), 2021 Level-1 Term-I, from BUTEX affiliated colleges. Covers elastic behaviour under load, modulus relation proofs, stored energy calculations, capillary rise, streamline versus turbulent flow, and angular momentum derivations.
Level-1 Term-I, Final Exám-2021
Subject: Physics-I (Code: PHY 101)
Time: 3.0 Hrs. Full Marks: 72
(Use separate answer script for Part: A and Part: B)
(All parts of a question must be answered consecutively)
Part: A
(Answer any three questions)
1. (a) Discuss the elastic behavior of a solid material wire of uniform cross section under different loads.
(b) If Y, k and σ represent Young's modulus, bulk modulus and Poisson's ratio respectively then prove that
(c) The Young’s Modulus of metal is 2 ×10¹¹ N/m² and its breaking stress is 1.078 ×10⁹ N/m². Calculate the maximum amount of energy per unit volume which can be stored in the metal when stretched.
[4+5+3=12]
2. (a) What is meant by surface energy? Show that the surface energy per unit area of a surface is equal to the surface tension.
(b) Derive an expression for the height ‘h’ through which a liquid of surface tension will rise in a capillary tube of radius r.
(c) Calculate the height to which a liquid will rise in a capillary tube of radius 0.22mm when surface tension of liquid is 26 ×10⁻³ Nm⁻¹ and density 1000 kgm⁻³. Assume the angle of contact is 0°.
[(1+3)+6+2=12]
3. (a) Distinguish between streamline and turbulent flow of liquid.
(b) State and derive Bernoulli’s theorem.