Two Physics-I papers (AS 105) from BUTEX affiliated colleges' 2019 Level-1 Term-I finals. Questions cover viscosity dimensions, Bernoulli's theorem with pipe flow numericals, elastic modulus relations, and Poisson's ratio calculations.
Q1
Level-1 Term-I, Final Exám-2019
Subject: Physics-I (Code: AS 105)
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) Define viscosity and co efficient of viscosity. Find the dimension of viscosity.
(b) Distinguish between streamline and turbulent flows of a liquid.
(c) State and prove Bernoulli's theorem for a liquid along a stream line.
(d) Water flows through a horizontal pipe of non-uniform cross-section. The pressure is 1cm of mercury where velocity of flow is 0.35 MS⁻¹. Find the pressure of a point where the velocity is 0.65 MS⁻¹.
[5+3+7+2.5=17.5]
2. (a) What is stream line motion?
(b) Explain the rate of flow of fluid in term's of mass of liquid.
(c) State and prove Bernoulli's theorem for fluid motion.
(d) Calculate the speed at which the velocity head of a stream of water is equal to 0.50m of Hg.
Q2
Level-1 Term-I, Final Exám-2019
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) What is turbulent motion?
(b) State and prove Bernoulli's theorem for fluid motion.
(c) Calculate the speed at which the velocity head of a stream of water is equal to 0.50m of Hg.
[(2+7+3)=12]
2. (a) What is meant by surface tension and surface energy? Show that the surface energy per unit area of a surface is equal to the surface tension.
(b) Define contact angle. 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 0.2mm when surface tension of liquid is 26x10⁻³Nm⁻¹ and density 800kg m⁻³. Take angle of contact 0°.
[4+6+2=12]
3. (a) Define stress and strain in graphical form.
(b) Prove that for a homogenous isotropic medium, Y=2η(1+σ), where the symbols have their usual meaning.
(c) What is poisson’s ratio? Show that the value of poisson’s ratio lies in between -1 and + ½.