# GTU previous years question papers -BE- Sem-III – Fluid Mechanics -Dec 2010

**GTU previous years question papers**

**GUJARAT TECHNOLOGICAL UNIVERSITY**

**B.E. Sem-III Regular / Remedial Examination December 2010**

**Subject code: 130602 **

**Subject Name: Fluid Mechanics**

** **

**Instructions:**

**1. Attempt all questions.**

**2. Make suitable assumptions wherever necessary.**

**3. Figures to the right indicate full marks.**

**Q.1 (a) **Explain the terms Dynamic Viscosity and Kinematics Viscosity. Also discuss

effect of temperature on viscosity.

**(b) **Explain with sketch the relationship between the absolute pressure, atmospheric

pressure and gauge pressure.

**Q.2 (a) **State the Bernoulli’s equation and obtain Bernoulli’s equation from Euler’s equation of motion.

**(b) **Derive Darcy Weisbach equation for loss of head in a pipe due to friction. ** **

**OR**

**(b) **Calculate the discharge through a rectangular orifice 2 m wide and 1.6 m deep

fitted to a water tank. The water level in the tank is 2.7 m above the top edge of

the orifice. Take Coefficient of discharge = 0.62

** ****Q.3 (a) **Define : (1) Specific Weight (2) Buoyancy (3) Meta Centric Height (4)

Hydraulic Gradient Line (5) Co-efficient of Contraction (6) Mach Number (7) Capillarity

** ****(b) **Explain the conditions of equilibrium of a floating and submerged body. ** **

**OR**

**Q.3 (a) **Determine the total pressure and depth of centre of pressure on a triangular plate

of base 3 m and altitude 3 m which is immersed in the water in such a way that

plan of the plate makes an angle of 60° with the free surface. The base of the

plate is parallel to water surface and at a depth of a 2 m from water surface.

**(b) **Explain analytical Method to determine Metacentric height. ** **

**Q.4 (a) **Explain Flow Net in details. Also discuss its characteristics, Utility and Limitations.

** ****(b) **The Water is flowing through a pipe having diameters 30 cm and 12 cm at

section 1 and 2 respectively. The rate of flow through pipe is 40 litres/second.

The section 1 is 8 m above datum and section 2 is 6 m above datum. If the

pressure at section 1 is 42 N/cm2, find the intensity of pressure at section 2.** **

**OR**

**Q.4 (a) **Derive expression for rate of flow through venturimeter. ** **

**(b) **The velocity potential function is given by ф = 5 (x2 – y2). Calculate the velocity

components at the point (4,5).

**Q.5 (a) **Prove that velocity of sound wave is equal to square root of the ratio of change of pressure to change of density of a fluid due to disturbance.

**(b) **Derive an expression for loss of head due to sudden contraction. ** **

**OR**

**Q.5 (a) **Derive an equation for discharge over a rectangular notch. ** **

**(b) **Write short note on flow through pipe in series. ** **