CE 3142 Applied Fluid Mechanics Lab - Mid-Term Quiz (Answered 100% 2025/26) Already Graded A' - University of Texas, Arlington.

CE 3142 Applied Fluid Mechanics Lab - Mid-Term Quiz (Answered 100% 2025/26) Already Graded A' - University of Texas, Arlington. Instructions: • This paper has two parts: Part A (MCQs) and Part B (Numericals). • Answer all questions in Part A. • In Part B, attempt any five questions. • Use: ρ = 1000 kg/m3, g = 9.81 m/s2 • Calculators allowed. No electronic gadgets permitted. Part A – Conceptual MCQs (20 × 0.5 = 10 marks) Tick the correct option for each of the following questions: 1. Which point is the location where the resultant hydrostatic force is assumed to act on a submerged surface? a) Centroid b) Center of pressure c) Center of buoyancy d) Metacenter 2. As the depth of immersion increases for a vertical surface, the hydrostatic force: a) Decreases b) Remains constant c) Increases linearly d) Increases exponentially 13. The hydrostatic force on a submerged surface always acts: a) Horizontally b) Vertically downward c) Perpendicular to the surface d) Tangential to the surface 4. In the hydrostatic pressure experiment, the experimental depth of center of pressure is affected by: a) Fluid density b) Shape of the surface c) Lever arm and balance mass d) All of the above 5. Bernoulli’s equation is based on which principle? a) Conservation of mass b) Conservation of energy c) Conservation of force d) Newton’s second law 6. In a converging duct, the pressure head will typically: a) Increase b) Decrease c) Remain constant d) Fluctuate randomly 7. In a pipe of varying cross-section under steady flow, which point will have the highest velocity? a) The widest section b) The point at highest elevation c) The narrowest section d) The inlet 28. Which of the following is neglected in Bernoulli’s equation in ideal conditions? a) Pressure head b) Elevation head c) Velocity head d) Viscous loss 9. In a real fluid flow system, the total head decreases along the direction of flow because of: a) Pumping b) Viscosity and energy losses c) Added potential energy d) Increased pipe diameter 10. Minor losses in pipe flow typically occur due to: a) Pipe length b) Friction along the walls c) Fittings, bends, and valves d) Flow rate 11. Among standard fittings, the highest head loss usually occurs at: a) Elbow b) Gate valve c) Sudden expansion d) Straight pipe 12. The loss coefficient (K) depends primarily on: a) Fluid temperature b) Type of fitting and flow regime c) Pipe color d) Elevation of the pipe 13. In the fittings experiment, if the flow rate increases, the energy loss: a) Decreases b) Remains constant c) Increases d) Vanishes 314. In Bernoulli’s experiment, pressure is lowest at: a) The inlet b) The widest section c) The throat of the venturi d) The outlet 15. Which parameter is most directly used to calculate discharge in a rectangular notch? a) Water density b) Crest elevation c) Head over the notch d) Nappe shape 16. The coefficient of discharge (Cd) accounts for: a) Nappe aeration b) Simplified assumptions in theory c) Surface tension d) Experimental setup only 17. In the weir experiment, why is the datum level (h0) taken at the crest? a) For aesthetics b) To normalize pressure c) To calculate net head accurately d) It’s an arbitrary convention 18. The center of pressure lies the centroid for a vertical submerged plane surface: a) Above b) Below c) At the same location d) Cannot be determined 19. Which measuring device is used in the Bernoulli’s theorem apparatus to determine pressure difference? a) Pitot tube b) Venturi meter c) U-tube manometer d) Orifice meter 420. When pressure head drops significantly but velocity head increases across a fitting, the situation most likely indicates: a) Contraction b) Sudden expansion c) Laminar flow d) Cavitation 5Part B - Short Numericals (5 × 2 = 10 marks) Attempt any five of the following six questions. Use appropriate units and show all steps clearly. Q1. A vertical rectangular surface of width 0.3 m and height 0.4 m is fully submerged in water. The depth to the centroid of the surface from the water surface is h¯ = 0.4 m. Calculate the theoretical depth to the center of pressure hp. Q2. In a horizontal pipe, the pressure head at section 1 is 0.25 m and the velocity is 0.4 m/s. At section 2, the pressure head drops to 0.10 m. Calculate the velocity at section 2. 6Q3. The pressure head before and after a pipe fitting is measured as 1.30 m and 1.05 m respectively. If the velocity is 1.2 m/s, calculate the loss coefficient K. Q4. A rectangular notch has a width of 0.04 m. If the head above the crest is 0.06 m, calculate the discharge. Use Cd = 0.62. Q5. A gate valve causes a pressure drop of 0.6 bar. The flow rate is 0.0009 m³/s and the pipe diameter is 0.0183 m. Estimate the loss coefficient K. 7Q6. Water flows through a horizontal tapered pipe. At section A (diameter = 100 mm), pressure = 20 kPa, velocity = 0.6 m/s. At section B (diameter = 50 mm), calculate the pressure at section B. Formulas Provided • Q = 2 3Cdb√2gH3/2 • A = πD2 4 ; A = b.d • P1 ρg + v12 2g = P2 ρg + v22 2g • K = 2g(h1−h2) v2 • v2 = pv12 + 2g(h1 − h2) • K = 2gh v2 • v = Q A • F = ρgAh¯ • A1v1 = A2v2 • h = P ρg • IG = bd3 12 • h p = h¯ + AIGh¯ End of Paper 8