## Fluid Mechanics - 1 - May 2014

### Civil Engineering (Semester 3)

TOTAL MARKS: 80

TOTAL TIME: 3 HOURS
(1) Question 1 is compulsory.

(2) Attempt any **three** from the remaining questions.

(3) Assume data if required.

(4) Figures to the right indicate full marks.

### Attempt any four of following

**1 (a)** What is monometer? How they are classified.(5 marks)
**1 (b)** What are the assumptions made in deriving Bernoulli's equation? Explain limitations.(5 marks)
**1 (c)** Explain capillarity and surface tension.(5 marks)
**1 (d)** Write a short note on flow past a Rankine oval body.(5 marks)
**1 (e)** Explain discharge over a Broad crested weir.(5 marks)
**1 (f)** What is an orifice and a multipiece? Give classification of orifices.(5 marks)
**2 (a)** Describe specific weight and compressibility of fluid.(4 marks)
**2 (b)** Show relationship between dynamic viscosity and velocity gradient. Classify fluids based on this relationship.(6 marks)
**2 (c)** Two large horizontal plane surface are 20m apart. This space is filled with glycerence. Find what force is required to drag a very thin plate of area 0-6m^{2} between the two surface at a speed of 0-70m/sec.

i) If the plate is equidistant from the two surfaces.

ii) If the plate is 7-5mm from the one of the surfaces. Take the dynamic viscosity of glycerene equal to 8.04×10^{-1}Ns/m^{2}(10 marks)
**3 (a)** State and prove the pascal's law.(10 marks)
**3 (b)** A hollow cylinder of outer diameter 1m, inner diameter 0-75m, weights 2h kN. Where 'h' is the height of cylinder. It is required to float in water with its longitudinal axis vertical. Calculate the height of cylinder.(6 marks)
**3 (c)** Explain the following

i) Lagrangian method and Exlerian method.

ii) Stable, unstable and netural equllibrium.(4 marks)
**4 (a)** Describe condition of stability of floating body in detail.(10 marks)
**4 (b)** An orifice meter with orifice diameter 10cm is inserted in a pipe of 20cm diameter. The pressure gauges fitted up stream and downstream of the orifice meter gives reading of 19.62N/cm^{2} and 9.81N/cm^{2} respectively Co-efficent of discharge for the orifice meter is given as 0.6. Find the discharge of water through pipe.(10 marks)