#### 4HE - Fluid Mechanics

Test - 1         Maximum Marks : 30         Duration : 90 min
Part - A (10 X 1 = 10 Marks)

1. What is a Newtonian fluid? Give examples.
2. Absolute pressures and temperatures must be employed when using the ideal gas law.(True/False)
3. To convert the pressure from gauge to absolute, add approximately 1.01 Pa.(True/False)
4. It is possible to have gauge pressures that are as low as -20 psig.(True/False)
5. A vertical pipe full of water, 34 ft high and open at the top, will generate a pressure of about one atmosphere (gauge) at its base.(True/False)
6. Why are specific gravities most often referred to the density of water at 4oC instead of at 0oC?
7. Most swimmers find the pressure at a depth of about 10 ft painful to ears. What is the gauge pressure at this depth?
8. A new submarine can safely resist an external pressure of 1000 psig. How deep in the ocean can it safely dive?
9. Give suitable examples for (a) Bingham plastic fluid, (b) Thixotropic fluid
10. Give the continuity equation for three dimensional flow
11. Part - B (2 X 10 = 20 Marks)

12. Derive an expression for the pressure difference across two limbs of a differential manometer containing two gauge fluids, mutually immissible. What factors influence the sensitivity?
13. Or

14. A differential manometer is used to measure the pressure drop in a pipeline conveying methane gas at 20 oC and 1 atm pressure. The two liquids in the differential manometer are kerosene (specific gravity 0.82) and water. The inside diameter of the reservoirs and the U-tube manometer are 5cm and 0.5cm respectively. If the reading in the manometer is 15cm, calculate the pressure difference indicated, when the change in levels in the reservoir (i) is neglected and (ii) is taken into account.
15. Calculate the power required and the pressure which should be developed by a pump of efficiency 80% to pump 60 liters/ min. of 98% sulfuric acid at 25oC from an open tank at ground level to a closed overhead tank at a gauge pressure of 2 atm kept 3m above the ground. The density of the acid is 1850kg/m3 and the viscosity is 25 centipoises. Neglect frictional losses.
16. Or

17. Show that the average velocity of the fluid flowing through a circular pipe under laminar conditions is half that of the maximum velocity.

© M.Subramanian, Lecturer, Chemical Engg, SVCE, Sriperumbudur - 602105, Tamil Nadu, INDIA