Question Bank (Objective Questions ) for Mid Exam II

1.      Define Impact of Jets?

2.      The force exerted by a jet impinging normally on a stationary fixed plate is __________

3.      The Force exerted by the jet on a stationary curved plate is ____________

4.      The Force exerted by the jet on a stationary inclined plate is _______________

5.      The force exerted by a jet impinging normally on moving fixed plate is __________

6.      The Force exerted by the jet on a moving curved plate is ____________

7.      The Force exerted by the jet on a moving inclined plate is _______________

8.      Define Hydraulic Efficiency of a turbine?

9.      Work done per second by unit weight of water on turbine = _______

10.  Velocity of water in the nozzle in Pelton Wheel is given by V = ____________

11.  The Vane angle (q) at Inlet in Pelton Wheel is __________ degrees.

12.  The speed of an imaginary turbine, identical with the given turbine, which will develop a unit power under a unit head, is known as _____________

13.  A Pelton wheel develops 1750 kW under a head of 90 m while running at 200 rpm and discharging 2500 litres of water per second. The unit power of the wheel is ___________

14.  Turbine preferred for up to 25 m head of water is _________                                       

15.  The turbine preferred for a specific speed of 60 to 300 rpm is __________                   

16.  A centrifugal pump will start delivering liquid only when the pressure rise in the impeller is equal to ________  

17.  Define a Hydraulic Turbine?

18.  Define Unit Speed of Turbine?

19.  Speed Ratio of Pelton Wheel means ______________

20.  Overall Efficiency of a turbine is ________________

21.  Condition for maximum efficiency in Pelton Wheel is ________________

22.  The discharge through a nozzle in Pelton Wheel is given by Q = _______________

23.  The discharge through a Francis Turbine is given by Q = _______________

24.  The discharge through a Kaplan Turbine is given by Q = _______________

25.  Define Centrifugal Pump?

26.  What is Manometric Head?

27.  1 H.P. = _______ Watts

28.  The specific speed of a centrifugal pump, delivering 750 litres of water per second against a head of 15 metres  at 700 rpm is ____________

29.  _________ is the head against which a Centrifugal Pump has to work.

30.  What is Unit Speed?

31.  What is Unit Power?

32.  What is Unit Discharge?

33.  Define Specific Speed of Turbine?

34.  What is the function of Draft Tube?

35.  Define Cavitation?

36.  What is the necessity of Surge Tank?

37.  What is Water Hammer?

38.  What is Multistage Pump?

39.  What are the Dimensionless Numbers used in Model Analysis of Turbine?

40.  What are the Dimensionless Numbers used in Model Analysis of Centrifugal Pump?

Question Bank for Mid Exam II

Unit III

1.    Define Impact of jets?

2.    State and explain momentum equation. What are the practical applications of it?

3.    Obtain an expression for the force exerted by a jet of water on a fixed vertical plate in the direction of the jet.

4.    Obtain an expression for the force exerted by a jet of water on a fixed inclined plate in the direction of the jet.

5.    Obtain an expression for the force exerted by a jet of water on a fixed curved plate in the direction of the jet.

6.    Obtain an expression for the force exerted by a jet of water on a moving vertical plate in the direction of the jet.

7.    Obtain an expression for the force exerted by a jet of water on a moving inclined plate in the direction of the jet.

8.    Obtain an expression for the force exerted by a jet of water on a moving Curved plate in the direction of the jet.

Unit IV

9.    Define Hydraulic Efficiency of turbine    

10.  Draw typical velocity triangles for inlet and outlet of Pelton wheel.

11.  Draw typical velocity triangles for inlet and outlet of Francis Turbine

a.    When b < 90⁰

b.    When b = 90⁰

c.    When b > 90⁰

12.  Distinguish between Impulse and Reaction Turbines.

13.  How are turbines classified? Explain

14.  What do you understand by unit speed of a turbine? What is its use?

15.  Distinguish between unit speed and specific speed

16.  How do you compare the performance of a turbine under different working conditions?

17.  What are the requirements of a governor in hydropower Installation?

18.  What is a draft tube? Why is it used in a reaction turbine? Explain with the help of sketches two different types of draft tubes?

19.  What are the constant efficiency curves of a turbine? What are their uses?

20.  What is Cavitation? What are the physical indicators for the presence of cavitation in turbines?

Unit V

21.  Define a centrifugal pump. Explain the principle and working of a single stage centrifugal pump.

22.  What is multistage pump and what are its advantages

23.  What is meant by priming of pumps?

24.  Draw typical velocity triangles for inlet and outlet of Centrifugal Pump

25.  Obtain expression for the work done by impeller of a centrifugal pump on water per second per unit weight of water

26.  Define specific speed of a centrifugal pump. What is its significance?

27.  Define static and manometric head of a centrifugal pump. State the different types of head losses which may occur in a pump installation.

28.  Define Cavitation. What are the effects of cavitation? Give necessary precautions against cavitation

Numerical Problems

Practice all questions which are covered in Class Room

Unit V - Centrifugal Pumps

Centrifugal Pumps from Dr. Rambabu Palaka

Unit IV - Hydraulic Turbines

Hydraulic Turbines from Dr. Rambabu Palaka

Unit III - Impact of Free Jets

Impact of Free Jets from Rambabu Palaka

OCF & HM - Question Bank

• Download Theory Questions
• Download Numerical Problems
• Download Objective Questions

Unit II - Dimensional Analysis

Dimesional Analysis from Rambabu Palaka

Unit I - Open Channel Flow

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Open Channel Flow from Rambabu Palaka
 

Unit I & II - Question Bank

• Theory Questions  
• Problems

GATE Exam Syllabus for Civil Engineering - CE

Hydraulics: Forces on immersed bodies; Flow measurement in channels and pipes; Dimensional analysis and hydraulic similitude; Kinematics of flow, velocity triangles; Basics of hydraulic machines, specific speed of pumps and turbines; Channel Hydraulics -Energy-depth relationships, specific energy, critical flow, slope profile, hydraulic jump, uniform flow and gradually varied flow

Open Channel Flow - Video

Open Channel Flow

Unit I - PPT

Download PPT of Unit - I of Open Channel Flow & Hydraulic Machinery

Introduction to Fluid Mechanics

A Fluid is a substance that deforms continuously when subjected to a shear stress no matter how small that shear stress may be.  

Differentiate solid and fluid.Fluid
The fluid deforms continuously when subjected to a shear stress.When the shear stress disappears the fluid never regain in to original shape. 

Solid
The Solid deforms a definite amount when subjected to a shear stress. When the shear stress disappears solids gain fully or partly their original shape


Fluid Mechanics is the branch of science that studies the behavior of fluids when they are in state of motion or rest. 

Fluid mechanics deals with three aspects of the fluid: static, kinematics, and dynamics aspects:

1. Fluid statics: The fluid which is in state of rest is called as static fluid and its study is called as fluid statics.
2. Fluid kinematics: The fluid which is in state of motion is called as moving fluid. The study of moving fluid without considering the effect of external pressures is called as fluid kinematics.
3. Fluid dynamics: The branch of science which studies the effect of all pressures including the external pressures on the moving fluid is called as fluid dynamics.

Fluid Properties:
Properties of fluids determine how fluids can be used in engineering and technology. They also determine the behavior of fluids in fluid mechanics. The following are some of the important basic properties of fluids:

1.     Density is  mass per unit volume of a fluid
2.     Viscosity is an amount of resistance of the fluid to shear stress. In a liquid, viscosity decreases with increase in temperature. In a gas, viscosity increases with increase in temperature.
3.     Temperature
4.     Surface Tension 
5.     Capillarity
6.     Pressure
7.     Specific Volume  is the volume of a fluid (V) occupied per unit mass (m). It is the reciprocal of density.
8.     Specific Weight is the weight possessed by unit volume of a fluid.
9.     Specific Gravity is the ratio of specific weight of the given fluid to the specific weight of standard fluid.

Real and Ideal fluids
The main difference between an ideal fluid and a real fluid is that for ideal flow p1 = p2 and for real flow p1 > p2. Ideal fluid is in-compressible and has no viscosity. Real fluid has viscosity. Water is considered as Ideal Fluid.

Application of Fluid Mechanics:

1. Water Resource Engineering, in which water must be delivered to consumers and disposed of after use, 
2. Water Power Engineering, in which water is used to generate electric power, 
3. Flood Control and Drainage, in which flooding and excess water are controlled to protect lives and property, 
4. Structural Engineering, in which wind and water create forces on structures 

Pascal's Law states,
" The intensity of pressure at any point in a fluid at rest, is the same in all direction."

Bernoulli's principle states,
" For a perfect in-compressible liquid, flowing in a continuous stream, the total energy of a particle remains the same, while the particle moves from one point to another."

This statement is based on the assumption that there are no losses due to friction in the pipe. Mathematically,
 

 

Darcy's formula for loss of head in pipe
When the water is flowing in a pipe, it experiences some resistance to its motion, whose effect is to reduce the velocity and ultimately the head of water available. An empirical formula for the loss of head due to friction was derived by Henry Darcy.

The loss of head due to friction according to Darcy is,

The equation of continuity
The equation of continuity states that for an in-compressible fluid flowing in a pipe of varying cross-section, the mass flow rate is the same everywhere in the pipe. The mass flow rate is simply the rate at which mass flows past a given point, so it's the total mass flowing past divided by the time interval. The equation of continuity can be reduced to:

Generally, the density stays constant and then it's simply the flow rate (Av) that is constant.


A1.V1 = A2.V2