How Gas Turbine Power Plant Work ?

Gas Turbine Power Plant

Gas turbine power plant:-

A generating station which employs gas turbine as the prime mover for the generation of electrical energy is known as a gas turbine power plant.

How Gas Turbine Power Plant Work?

In a gas turbine power plant, air is used as the working fluid. The air is compressed by the compressor and is led to the combustion chamber where heat is added to air, thus raising its temperature. Heat is added to the compressed air either by burning fuel in the chamber or by the use of air heaters. The hot and high-pressure air from the combustion chamber is then passed to the gas turbine where it expands and does the mechanical work. The gas turbine drives the alternator which converts mechanical energy into electrical energy.

In a gas turbine power plant we use high pressure and temperature air instead of high pressure and temperature steam to rotate the turbine.

In a gas Turbine Power Plant compressor, gas turbine and the alternator are mounted on the

same shaft so that a part of mechanical power of the turbine can be utilised for the operation of the compressor. Gas turbine power plants are being used as standby plants for hydroelectric stations, as a starting plant for driving auxiliaries in power plants etc.

Advantages

(i) It is simple in design as compared to steam power station since no boilers and their auxiliaries are required. (ii) It is much smaller in size as compared to steam power station of the same capacity. This is expected since gas turbine power plant does not require boiler, feed water arrangement etc.

(iii) The initial and operating costs are much lower than that of equivalent steam power station. (iv) It requires comparatively less water as no condenser is used. (v) The maintenance charges are quite small. (vi) Gas turbines are much simpler in construction and operation than steam turbines. (vii) It can be started quickly form cold conditions. (viii) There are no standby losses. However, in a steam power station, these losses occur because boiler is kept in operation even when the steam turbine is supplying no load.

Disadvantages

(i) There is a problem for starting the unit. It is because before starting the turbine, the compressor has to be operated for which power is required from some external source. How-ever, once the unit starts, the external power is not needed as the turbine itself supplies the necessary power to the compressor. (ii) Since a greater part of power developed by the turbine is used in driving the compressor, the net output is low. (iii) The overall efficiency of such plants is low (about 20%) because the exhaust gases from the turbine contain sufficient heat. (iv) The temperature of combustion chamber is quite high (3000℉) so that its life is compara-tively reduced. 

What is Load Curve ? | Daily Load Curve & Important Factor

 What Is Load Curve?

The curve showing the variation of load on the Power station with respect to (w.r.t.) time is known as a load curve.

The load on a power station is never constant; it varies from time to time. These load variations during the whole day (i.e., 24 hours) are recorded half-hourly or hourly and are plotted against time on the graph. The curve thus obtain known as daily load curve as it shows the variations of load w.r.t time during the day. Figure below shows a typical daily load curve of a power station.

 Note:-  IN EASY WAY TO UNDERSTANDING

1.These load variations during the whole day are recorded half hourly or hourly and are plotted against time on the graph. The curve thus obtained is known as daily load curve.

2.The monthly load curve can be obtained from the daily load curves of that month.

➢ For this purpose, average values of power over a month at different times of the day are calculated and then plotted on the graph.

➢ The monthly load curve is generally used to fix the rates of energy.

3. The yearly load curve is obtained by considering the monthly load curve of that particular year.

➢ The yearly load curve is generally used to determine the annual load factor.

Important Terms:

(i) Connected load:  It is the sum of commences ratings of all the equipment’s connected to supply system.

(ii) Maximum demand: It is the greatest demand of load on tire power station during a given period.

(iii) Demand factor:  It is the ratio of maximum demand on the power station to its connected load i.e. 

The value of demand factor is usually less than 1. It is expected because maximum demand on the power station is generally less than the corrected load.

(iv) Average load:  The average of loads occurring on the power station in a given period (day or month or year) is known as average load or average demand.

(v) Load factor:  The ratio of average load to the maximum demand during a given period is known as load factor i.e.,

Load factor is always less than 1 because the average load is smaller than the maximum demand. Higher the load factor of the power station, lesser will be the cost per unit generated.

(vi) Diversity factor:  The ratio of the sum of individual maximum demands to the maximum demand on power station is known as diversity factor i.e.,

(vii) Plant capacity factor: It is the ratio of actual energy produced to the maximum possible energy that could have been produced during a given period i.e.,

(viii) Plant use factor: It is ratio of kWh generated to the product of plant capacity and the number of hours for which the plant was in operation i.e.,

How Diesel Power Station Works | Electricalk4u

Diesel Power Station

A generating station in Which diesel engine is used as the prime over for the generation of electrical energy is known as diesel power station.

In a diesel power station, diesel engine is used as the prime mover. The diesel burns inside the engine and the products of this combustion act as the ”working fluid” to produce mechanical energy. The diesel engine drives the alternator which converts mechanical energy into electrical energy.

Diesel Power Station Important Parts 

(i) Fuel supply system. 

It consists of storage tank, strainers, fuel transfer pump and all day fuel tank. The fuel oil is supplied at the plant site by rail or road. This oil is stored in the storage tank. From the storage tank, oil is pumped to smaller all day tank at daily or short intervals. From this tank, fuel oil is passed through strainers to remove suspended impurities. The clean oil is injected into the engine by fuel injection pump.

(ii) Air intake system. 

 This system supplies necessary air to the engine for fuel combustion. It consists of pipes for the supply of fresh air to the engine manifold. Filters are provided to remove dust particles from air which may act as abrasive in the engine cylinder.

(iii) Exhaust system.

  This system leads the engine exhaust gas outside the building and dis-charges it into atmosphere. A silencer is usually incorporated in the system to reduce the noise level

(iv) Cooling system. 

The heat released by the burning of fuel in the engine cylinder is partially converted into work. The remainder part of the heat passes through the cylinder walls, piston, rings etc. and may cause damage to the system. In order to keep the temperature of the engine parts within the safe operating limits, cooling is provided. The cooling system consists of a water source, pump and cooling towers. The pump circulates water through cylinder and head jacket. The water takes away heat form the engine and itself becomes hot.The hot water is cooled by cooling towers and is recirculated for cooling.

(v) Lubricating system. 

This system minimises the wear of rubbing surfaces of the engine. It comprises of lubricating oil tank, pump, filter and oil cooler. The lubricating oil is drawn from the lubricating oil tank by the pump and is passed through filters to remove impurities. The clean lubricating oil is delivered to the points which require lubrication. The oil coolers incorporated in the system keep the temperature of the oil low.

(vi) Engine starting system. 

This is an arrangement to rotate the engine initially, while starting, until firing starts and the unit runs with its own power. Small sets are started manually by handles but for larger units, compressed air is used for starting. In the latter case, air at high pressure is admitted to a few of the cylinders, making them to act as reciprocating air motors to turn over the engine shaft. The fuel is admitted to the remaining cylinders which makes the engine to start under its own power.

Advantages:

1.  The design and layout of the plant are quite simple.

2.  It occupies less space as the number and size of the auxiliaries is small.

3.  It can be located at any place. 

4.  It can be started quickly and can pick up load in a short time.

5.  There are no standby losses.

6.  It requires less quantity of water for cooling.

7.  The overall cost is much less than that of steam power station of the same capacity.

8.  The thermal efficiency of the plant is higher than that of a steam power station.

Disadvantages:

1.  The plant has high running charges as the fuel (i.e., diesel) used is costly.

2.  The plant does not work satisfactorily under overload conditions for a longer period.

3.  The plant can only generate small power.

4.  The cost of lubrication is generally high.

5.  The maintenance charges are generally high.

Nuclear Power Plant or Nuclear Power Station

Nuclear Power Plant or Nuclear Power Station 

Nuclear Power Station:-

A generating station in which nuclear energy is converted into electrical energy is known as a nuclear power station.

Nuclear Reactor:

➢ In a nuclear reactor, the energy is released because of nuclear fission. This energy is absorbed by the hot coolant. The heat exchanger is used for converting water into steam using the coolant and this steam is sent to the turbine for power generation.

Moderator:

➢ It is used to reduce speed of the neutron. The material used as a moderator has low molecular weight. In case of enriched plants, ordinary water is used as a moderator. In case of natural uranium plant, the material graphite, heavy and light water, Beryllium and its oxide is used.

Control Rod:

➢ It is used for absorbing acess neutrons produced during chain reaction. Materials cadmium Boron and Hafnium are used as control rod.

Coolant:

➢ It transfers heat produced inside the reactor to the heat exchanger for conversion of Water to steam.

➢ Materials: Water, Heavy Water, Liquid Sodium, Helium, Co2 or Sodium- potassium alloy is liquid form.

Heat Exchanger:

➢ The coolant gives up heat to the heat exchanger which is utilized in raising the steam. After giving up heat, the coolant is again fed to the reactor.

Note:

1. Complete fission of 1kg of Nuclear Fuel (U235)can produce as much energy as can be

produced by the burning of 275 tons (2,75,000kg) of high grade coal.

2. Nuclear Fuel

➢ Enriched Uranium – U92238– 99.3% of fuel

➢ Natural Uranium – U92235– 0.07% of fuel

➢ Thorium – Th90232

Selection of site for Nuclear Power Station:

1. Availability of Water

2. Disposal of Water

3. Distance from Populated area

4. Transportation Facilities

Advantages

(i) The amount of fuel required is quite small. Therefore, there is a considerable saving in the cost of fuel transportation.

(ii) A nuclear power plant requires less space as compared to any other type of the same size.

(iii) It has low running charges as a small amount of fuel is used for producing bulk electrical energy.

(iv) This type of plant is very economical for producing bulk electric power.

(v) It can be located near the load centres because it does not require large quantities of water and need not be near coal mines. Therefore, the cost of primary distribution is reduced.

(vi) There are large deposits of nuclear fuels available all over the world. Therefore, such plants can ensure continued supply of electrical energy for thousands of years.

(vii) It ensures reliability of operation.

Disadvantages

(i) The fuel used is expensive and is difficult to recover.

(ii) The capital cost on a nuclear plant is very high as compared to other types of plants.

(iii) The erection and commissioning of the plant requires greater technical know-how.

(iv) The fission by-products are generally radioactive and may cause a dangerous amount of

radioactive pollution

(v) Maintenance charges are high due to lack of standardization. Moreover, high salaries of

specially trained personnel employed to handle the plant further raise the cost.

(vi) Nuclear power plants are not well suited for varying loads as the reactor does not respond to the load fluctuations efficiently.

(vii) The disposal of the by-products, which are radioactive, is a big problem. They have either to be disposed off in a deep trench or in a sea away from sea-shore.

Hydro-electric Power Plant or Hydro-electric Power Station

Hydro-electric Power Plant or (Hydro-electric Power Station)

Hydro-electric Power Station:-

A generating station which utilizes the potential energy of water at a high level for the generation of

electrical energy is known as a hydroelectric power station.

Principle:-

➢A Dam is a barrier which stores water and creates water head. The type and arrangement

depends upon the topography of the site, foundation conditions, local materials and transportation available, occurrence of earthquake and other hazards.

➢ A spillway is used to protect the dam from the floods in the water level is beyond capacity of the

dam it is used as safety valve to the dam.

➢ A surge tank is used in medium and large head plants with closed conduit type penstocks. It is used to protect penstocks form water hammering effect.

➢ Surge Tank is also used to supply additional water in case of sudden load demands.

➢ Penstocks are open or closed conduit which carry water from reservoir to the turbines.

➢ Concrete penstocks are suitable for low heads (<30m) as greater pressure causes rapid

deterioration of concrete.

➢ The steel penstocks can be designed for any head the thickness of the penstock, increase with the

head or working pressure.

➢ The area of rainwater collected for storing of water in the dam is called catchment area.

➢ The amount of percentage of water which is converted into streams/river after evaporation

and filtration by land is called yield factor.

Types of Turbine:

(a) Based on Water Head (H) :-

Head	Turbine
< 15m	Kaplan (or) Movable Vane Propeller
15 to 70m	Kaplan (or) Francis
70 to 500 m	Francis (or) Pelton
> 500 m	Impulse (or) Pelton

(b) Based on Water in Penstocks:

Turbine	Water in Penstock
Pelton	8m/sec
Francis	4m/sec
Kaplan	2m/sec

(c) Based on speed (RPM):

Turbine	Speed (RPM)
Pelton	13 – 70
Francis	70 – 400
Kaplan	400 – 1000

Choice of site for Hydro-electric Power Station

1. Availability of Water

2. Storage of Water

3. Cost and type of land

4. Transportation Facilities

Advantages

(i) It requires no fuel as water is used for the generation of electrical energy.

(ii) It is quite neat and clean as no smoke or ash is produced.

(iii) It requires very small running charges because water is the source of energy which is available free of cost.

(iv) It is comparatively simple in construction and requires less maintenance.

(v) It does not require a long starting time like a steam power station. In fact, such plants can be put into service instantly.

(vi) It is robust and has a longer life.

(vii) Such plants serve many purposes. In addition to the generation of electrical energy, they also help in irrigation and controlling floods.

(viii) Although such plants require the attention of highly skilled persons at the time of construction, yet for operation, a few experienced persons may do the job well.

Disadvantages

(i) It involves high capital cost due to construction of dam.

(ii) There is uncertainty about the availability of huge amount of water due to dependence on

weather conditions.

(iii) Skilled and experienced hands are required to build the plant.

(iv) It requires high cost of transmission lines as the plant is located in hilly areas which are quite

away from the consumers

Thermal Power Plant or Thermal Power Generation(Steam Power Station)

Thermal Power Plants 

Electrical Power Generation Station

Electrical Power Generation:-The conversion of energy available in different forms in nature into electric energy is called a generation of electrical energy.

Electrical Power Generation Plant 

Conventional                                                   Non-Conventional

1.Thermal Power Plant                                         1.Hydro-electric Power Plant

2.Nuclear Power Plant                                          2.Wind Power Plant

3.Gas Power Plant                                                 3.Solar Power Plant

4.Diesel Power Plant                                             4.Geothermal Power Plant

                                                                               5.Tidal Power Plant

Steam Power Station (Thermal Station):-

A generating station which converts heat energy of coal combustion into electrical energy is known as a steam power station.

Principle:

➢ Thermal plants work on the principle of Rankine cycle, in which, steam is reheated for improvement of thermal efficiency.

➢  From the coal storage plant, coal is delivered to the coal handling plant where it is pulverized (i.e.crushed into small pieces) in order to increase its surface exposure, thus promoting rapid combustion without using large quantity of air.

➢ The coal is burnt in the boiler and the ash product after the complete combustion of coal is removed to the ash handling plant and then delivered to the ash storage plant for disposal.

➢De-mineralized (DM) water is used to protect the boiler tubes from corrosion effect.

➢ Deaerator is used for removing air bubbles inside the water for protecting the boiler tubes.

➢ BFP (Boiler Feed Pump) is the highest pressure generating pump in thermal plant. It generates pressure upto 165kg and consume power upto 4MW.

➢ The steam produced in the boiler is wet and is passed through a super heater where it is dried and super heated (i.e. steam temperature increased above that of boiling point of water) by the flue gases on their way to chimney, which increases overall efficiency and prevent turbine blades from corrosion.

➢ Economizer is used to absorb heat from flue gas to increase the feed water temperature, which improves thermal efficiency.

➢ An Air preheater (APH) is used for increasing the temp. of the air supplied for coal burning by deriving heat from flue gas.

➢ Turbo separator are used inside the drum for separating water and steam.

➢ A condenser is a device which condens the steam at the exhaust of turbine. It serves two important functions. Firstly, it creates a very low pressure at the exhaust of turbine, thus permitting expansion of the steam in the prime mover to a very low pressure.

➢ This helps in converting heat energy of steam into mechanical energy in the prime mover.

➢ Vacuum pump and steam ejector are used in a condenser for absorbing steam from the turbine to the condenser.

➢ Most of the energy is wasted for conversion of steam into water inside the condenser so that thermal efficiency is between 35-40%

➢ Using cooling Tower, circulating water temperature is reduced.

➢ Primary Air (PA) fan is used to send coal powder from the coal mill to the boiler.

➢ Forced Draught (FD) fan is used to supply oxygen to the boiler for proper combustion.

➢ Induced Draught (ID) Fan is used to take flue gases from the boiler and released to the atmosphere through chimney.

➢ Electrostatic Precipitator (ESP) is used to collect ash particles from the flue gas. It works on the principal of electrostatic field.

➢ Natural water usually has pH value between 6.5 and 7.5 pH.

➢ A common recommendation is to maintain boiler water is 8.5 pH.

Choice of site for Steam / Thermal Power Plant:

1. Supply of fuel

2. Availability of Water

3. Transpiration facility

4. Coat and type of lands

5. Nearness to load center

6. Distance from populated area

Efficiency of Thermal Power Plant:

The overall efficiency of steam power station is quite low (about 35-40%) due mainly to two reasons

1. A huge amount of heat is lost in the condenser and

2. Heat losses occur at various stages of the plant

1. Thermal Efficiency:

➢ The ratio of heat equivalent to the mechanical energy transmitted to the turbine shaft to the heat of combustion of coal is known as thermal efficiency of thermal power plant.

Note:-

➢ More than 50% of total heat of combustion is lost in the condenser. The other/remaining heat losses occur in flue gases, radiation, ash etc.

2. Overall Efficiency:

➢ The ratio of heat equipment of electrical output to the heat of combustion of coal is known as overall efficiency of thermal power plant.

➢ Overall Efficiency = Thermal Efficiency X Electrical Efficiency

Advantages

(i) The fuel (i.e., coal) used is quite cheap.

(ii) Less initial cost as compared to other generating stations.

(iii) It can be installed at any place irrespective of the existence of coal. The coal can be transported to the site of the plant by rail or road.

(iv) It requires less space as compared to the hydroelectric power station.

(v) The cost of generation is lesser than that of the diesel power station.

Disadvantages

(i) It pollutes the atmosphere due to the production of large amount of smoke and fumes.

(ii) It is costlier in running cost as compared to hydroelectric plant.

Makaut(WBUT) 7th Sem Electrical Engineering (Power System III) Previous Year and Chapter Wise MCQ ⚡

Makaut(WBUT) 7th Sem Electrical Engineering Previous Year Question and Chapter Wise MCQ

👉SUBJECT----

📗   ELECTRIC DRIVE (EE-701)

📕   UTILIZATION OF  ELECTRIC POWER (EE-702)

📘   POWER SYSTEM - III (EE-703)

📙    RENEWABLE & NON-CONVENTIONAL ENERGY (EE-704)

📗   COMPUTER NETWORK (EE-705)

Power System Analysis T. K. Nagsarkar & M. S. Sukhija Download In Pdf

 Overview

Power Systems Analysis provides a thorough understanding of the principles and techniques of power system analysis and their application to real-world problems.
Beginning with basic concepts, the book gives an exhaustive coverage of transmission line parameters, symmetrical and unsymmetrical fault analysis and power flow studies. The book includes seperate chapters on state estimation, stability analysis and contingency analysis and also provides and introduction to HVDC and FACTS. Relevant topics such as power quality and power management are also dealt with. The book extensively illustrates the use of MATLAB in the analysis of power systems.
With its lucid style of presentation, the book should be useful to both students and practising engineers.

Description

The second edition of Power System Analysis serves as a basic text for undergraduate students of electrical engineering. It provides a thorough understanding of the basic principles and techniques of power system analysis as well as their application to real-world problems. Beginning with the basic concepts, the book gives an exhaustive coverage of transmission line parameters, simulation of power system elements, steady-state performance and travelling wave phenomena on transmission lines, symmetrical and unsymmetrical fault analyses, power flow studies, power system control, and stability analysis. The book extensively illustrates the use of MATLAB in the analysis of power systems. Owing to its lucid style and presentation of advanced topics, the book will be useful to postgraduate students as also to practising engineers.

Table of contents

Chapter 1. Power Sector Outlook
Chapter 2. Basic Concepts
Chapter 3. Transmission Line Parameters
Chapter 4. Transmission Line Model and Performance
Chapter 5. Simulation of Power System Components
Chapter 6. Formulation of Network Matrices
Chapter 7. Power Flow Studies
Chapter 8. Power System Controls
Chapter 9. Symmetrical Fault Analyses
Chapter 10. Symmetrical Components and Unsymmetrical Fault Analyses
Chapter 11. Power System Stability
Chapter 12. Voltage Stability
Chapter 13. Contingency Analysis Techniques
Chapter 14. State Estimation Techniques
Chapter 15. An Introduction to HVDC Power Transmission
Chapter 16. Introduction to FACTS

Features

• Chapter on voltage stability
• Sections on magnetohydrodynamic generation, significance of propagation constant, Ferranti effect on transmission lines, DC power flow solution, and HVDC converter operation
• MCQs with answers to help students gauge their understanding of concepts explained in the chapter, and chapter-end summary and a list of significant formulae for a quick reference
• Key Features
• Contains a large number of illustrative problems that use MATLAB in the analysis of power systems
• Includes advanced topics such as contingency analysis and state estimation
• Provides an introduction to HVDC and FACTS
• Includes numerous examples with step-by-step procedures and a variety of chapter- end problems
• Online Resources:
• For Faculty
• Solution manual
• For Students
• Academic Capability Test

Modern Power System Analysis By D.P. Kothari , I Nagrath Download In Pdf (FREE)

TABLE OF CONTENT

1. Introduction
2. Inductance and Resistance of Transmission Lines
3. Capacitance of Transmission Lines
4. Representation of Power System Components
5. Characteristics and Performance of Power Transmission Lines
6. Load Flow Studies
7. Optimal System Operation
8. Automatic Generation and Voltage Control
9. Symmetrical Fault Analysis
10. Symmetrical Components
11. Unsymmetrical Fault Analysis
12. Power System Stability
13. Power System Transients
14. High Voltage DC (HVDC) Transmission
15. Power System Security
16. Voltage Stability
17. An Introduction to State Estimation of Power Systems
18. Compensation in Power Systems
19. Load Forecasting Technique
Appendix A: Introduction to Vector and Matrix Algebra
Appendix B: Generalised Circuit Constants
Appendix C: Triangular Factorisation and Optimal Ordering
Appendix D: Elements of Power System Jacobian Matrix
Appendix E: Kuhn-Tucker Theorem
Appendix F: Real-time Computer Control of Power Systems
Appendix G: Some Aspects of Smart Grid
Appendix H: Introduction to MATLAB and SIMULINK
Appendix I: Substations
Appendix J: Convergence of Load Flow Methods
Appendix K: Power Quality: An Overview
Appendix L: Recent Trends in Power System Communication
Appendix M: Restructured and Deregulated Power System
Appendix N: Power System Reliability Studies
Appendix O: Emission Control
Appendix P: Generator Maintenance Scheduling
 

 Description

The book provides for an in-depth study of Power Systems Analysis, Power Systems Stability, and Power Systems Operation and Control courses as offered at the undergraduate level across Indian universities. The rich and robust content caters to the requirements of a related postgraduate course and will also greatly benefit practicing engineers. 

Modern Control Engineering 5th Edition Download in Pdf By Katsuhiko Ogata

Description

Ogatas Modern Control Engineering, 5 / e, offers the comprehensive coverage of continuous-time control systems that all senior students must have, including frequency response approach, root-locus approach and state-space approach to analysis and design of control systems. The text provides a gradual development of control theory, shows how to solve all computational problems with MATLAB, and avoids highly mathematical arguments. A wealth of examples and worked problems are featured throughout the text. The new edition includes improved coverage of Root - Locus Analysis (Chapter 6) and Frequency - Response Analysis (Chapter 8). The author has also updated and revised many of the worked examples and end-of-chapter problems.

features

• Chapter 8 first discusses PID control in general and then presents two-degrees-of-freedom control systems - Presents a computational (MATLAB) method to determine system parameters so the system will have the desired transient characteristics
• An improved chapter on the design of control systems in state space (Chapter 10) - This chapter treats pole placement and observer design and includes quadratic optimal control. MATLAB is extensively used in the design problems using pole placement and observer design
• An in-depth treatment of topics emphasizes both the basic concepts and the design aspects of control systems
• An accessible presentation that avoids highly mathematical arguments. The author introduces mathematical proofs only when they contribute to an understanding of the material
• Over 150 chapter-end worked problems and 180 unsolved problems clarify students' understanding of the material at strategic points throughout the text
• An introduction to the two-degrees-of-freedom control system and introduction to robust control. Presents a MATLAB approach to the design of high performance control systems
• A comprehensive coverage of root-locus analyses not found in other texts
• Detailed coverage of frequency response of control systems.

Multiple Choice Questions of Electric Traction.

1. Overall efficiency of steam locomotive system is close to

(A) 5 to 10%

(B) 25 to 30%

(C) 55 to 60%       

(D) 75 to 80%.

2. In a steam locomotive electric power is provided through

(A) battery system

(B) diesel engine generator

(C) overhead wire

(D) small turbo generator.

3. Maximum horse power of steam locomotive is

(A) 100

(B) 500

(C) 1500

(D)2500.

4. The pressure of steam in a locomotive is

(A) 10-15 kg/cm²

(B) 20 - 30 kg/cm²

(C) 40 - 50 kg/cm²

(D) 80 - 90 kg/cm².

5. The efficiency of diesel locomotives is nearly

(A) 20 - 25 percent

(B) 35 - 40 percent

(C) 50 - 55 percent

(D) 70 - 75 percent. 

6. The advantage of electric traction over other methods is

(A) no pollution problems

(B) faster acceleration

(C) better braking action

(D) all of the above.

 7. Suburban railways use

(A) 1500 V DC

(B) 440 V three phase AC

(C) 660 V three phase AC

(D) 3.3 kV three phase AC.

 8. Long distance railways use

(A) 200 V DC

(B) 25 kV Single phase AC

(C) 25 kV Two phase AC

(D) 25 kV Three phase AC.

 9. The range of horsepower for diesel locomotives is

(A) 100 to 500

(B) 500 to 1000

(C) 1500 to 2500

(D) 4000 to 5500.

 10. Steam Engine provided on steam locomotives is

(A) Single acting condensing type

(B) double acting condensing type

(C) double acting non - condensing type

(D) single acting non condensing type.

11. A submarine while moving under water, is provided driving power through

(A) diesel engines

(B) steam turbine

(C) gas turbine

(D) batteries.

12. Overload capacity of diesel engines is usually restricted to

(A) 1 %

(B) 10%

(C) 25%

(D) 50%.

13. Which locomotive has the highest operational availability

(A) Diesel

(B) Electric

(C) Steam

(D) All have same availability.

14. Which motor is used in tramways

(A) AC single phase capacitor start motor

(B) AC three phase motor

(C) DC series motor

(D) DC shunt motor.

15. A drive suitable for mines where explosive gas exist, is

(A) Diesel engine

(B) Steam engine

(C) Battery locomotive

(D) Any of the above.

16. The advantage of electric braking is

(A) is is instantaneous

(B) more heat is generated during braking

(C) it avoids wear of track.

(D) motor continue to remain loaded during braking.

17. Which braking system on the locomotives is costly

(A) Vacuum braking on steam locomotives

(B) Vacuum braking on diesel locomotives

(C) Regenerative breaking on electric locomotives .

(D) All breaking systems are equally costly.

 

18. The acceleration rate of trains on suburban services is

(A) 0.1 to 0.4 km phps

(B) 0.8 to 1 km phps

(C) 0.4 to 6.5 km phps

(D) 10 to 26 km phps.

19. The coasting retardation on trains is approximately

(A) 0.16 km phps

(B) 1.6 km phps

(C) 16 km phps

(D) 25 km phps.

20. The coefficient of adhesion is

(A) same on ac and dc traction systems

(B) high in case of dc traction and low in ac traction

(C) low in case of ac traction and high in dc traction.

21. Braking retardation on suburban trains is

(A) 0.3 to 0.5 km phps

(B) 0.5 to 1 km phps

(C) 3 to 5 km phps

(D) 30 to 40 km phps.

22. Power supply frequency for 25 kV single phase system is

(A) 161

(B) 25

(C) 50

(D) 60.

23. For supply on 25 kV, 50 Hz single phase, suitable motor for electric traction is

(A) ac single phase split phase motor

(B) ac single phase universal motor

(C) dc shunt motor

(D) dc series motor.

24. Method of speed control used on 25 kV, 50 Hz single phase traction is

(A) Tap changing control of transformer

(B) Reduced current method

(C) Series parallel operation of motors

(D) Any of the above.

25. The coefficient of adhesion is highest when

(A) the rails are dry

(B) the rails are oiled

(C) the rails ark wet with dew

(D) the rails are dusty.

  

26. When the speed of the train is estimated taking into account the time of stop at a station in addition to the actual running time between stops, is known as

(A) Average speed

(B) Schedule speed

(C) Notching speed

(D) Free running speed.

27. A schedule speed of 45 km, per hour is required between two stops 1.5 km apart. The duration of stop is 20 seconds. The acceleration is 2.4 km phps and retardation is 3.2 km phps. For a simplified trapezoidal curve the maximum speed over the mil will be

(A) 40 km per hour

(B) 48 km per hour

(C) 74 km per hour

(D) 90 km per hour.

28. Speed of locomotive is controlled by

(A) gear box

(B) flywheel

(C) regulating steam to engine

(D)applying brakes.

29. The specific energy consumption for suburban services is usually

(A) 18 to 25 watt-hours per tonne km

(B) 50 to 75 watt-hours per tonne km

(C) 125 to 150 watt-hours per tonne km

(D) 155 to 200 watt-hours per tonne km.

30. If the specific energy consumption for suburban services is 50 to 75 watts hours per tonne km, which of the following could be a representative figure for energy consumption on main line service

(A) 150 to 200 watt-hours per tonne km

(B) 100 to 125 watt-hours per tonne km

(C) 50 to 75 watt-hours per tonne km

(D) 20 to 30 watt-hours per tonne km.

 31. Specific energy consumption is least in

(A) urban service

(B) sub-urban service

(C) main-line service

(D) equal for all types of services.

32. Bearings used to support axles of rolling stock are

(A) Bush bearings

(B) Journal bearings

(C) Ball bearings

(D) Roller bearings.

33. If the coefficient of adhesion on dry rails 0.25. which of the following could be the value for wet rails ?

(A) 0.32

(B) 0.25

(C)0.245

(D) 0.15.

34. A train has a schedule speed of 36 km per hour on a level track. If the distance between the stations is 2 km and the stoppage is 30 seconds the actual time of run will be

(A) 260 seconds

(B) 230 seconds

(C) 200 seconds

(D) 170 seconds.

35. B₀ B₀ locomotives have two bogies with

(A) four driving axles each with individual driving motors

(B) three driving axles with group drives

(C) two driving axles with group drives

(D) two driving axles with individuals drive motor.

36. A locomotive exerts a tractive effort of 30,000 Newtons in pulling a train at 50 km per hour on the level hack. It is to haul the same train at the same speed on a gradient and the tractive effort required is 45000 Nw. The horse power delivered by the motor will be more if it is driven by

(A) dc series motors

(B) induction motor

(C) same in both cases.

37. A composite system consists of

(A) a combination of diesel engine and dc series motor

(B) a combination of diesel engine and ac single phase motor

(C) single phase power received is converted into dc or three phase power ac system

(D) use of combination of dc and ac motors on the same locomotive.

38. Horse power of steam locomotives is

(A) Up to 1500

(B) 1500 to 2500

(C) 2500 to 4000

(D) more than 4000.

39. Horse power of diesel locomotives is

(A) 1000 to 1500

(B) 1500 to 2500

(C) 2500 to 5000

(D) 5000 to 10,000.

40. Locomotives with manometer bogie have

(A) lot of skidding

(B) low coefficient of adhesion

(C) uneven distribution of tractive effect

(D) suitability for passenger as well as freight service.

41. The speed time curve for a local train is shown in Figure. In this AB represents

(A) Coasting

(B) Acceleration

(C) Braking

(D) Regeneration.

42. The duration for braking is represented by the time

(A) 0-t₁

(B) 0-t₂

(C)t₁ - t₂

(D)t₂- t₁

 43. Area under the curve represents

(A) average speed

(B) average acceleration

(C) net acceleration

(D) distance traveled.

44. From the figure it can be concluded that

(A) rate of acceleration is the same as the rate of acceleration during braking

(B) average acceleration is zero

(C) time taken during coasting is equal to the time during acceleration and braking

(D) during coating the acceleration is negative.

45. For tramways the return circuit is

(A) through cables

(B) through rails

(C) through neutral wire

(D) through common earthling.

46. For 600 V dc line for tram cars

(A) track is connected to negative of the supply

(B) track is connected to positive of the supply

(C) track is connected to mid voltage of 300 V

(D) none of the above.

47. Over head lines for power supply to tramcars are at a minimum height of

(A) 2 m

(B) 5 m

(C) 10 m

(D) 15 m. 

48. Which of the following traction system is latest used in the world ?

(A) 3 phase 3.7 kV

(B) 20 kV, 50 Hz. single phase

(C) 600 V, DC

(D) 3 kV, DC.

49. Which of the following frequencies not common in low frequency traction system ?

(A) 161 Hz

(B) 25 Hz

(C) 40 Hz.

50. In a long distance electric train, power for lighting in passenger coach is provided

(A) through locomotive

(B) directly through overhead electric line

(C) through individual generator of bogie and batteries

(D) through rails.

51. In Kando system

(A) single phase supply is converted into three phase system

(B) single phase ac is converted into dc

(C) three phase ac is converted into dc

(D) dc supply is due to run dc motors.

52. Free running and coasting periods arc generally long in ease if

(A) urban service

(B) sub-urban service

(C) main-line service

(D) all of the above.

 53. Which of the following factor affects specific energy consumption ?

(A) Distance between stops

(B) Gradient

(C) retardation and acceleration values

(D) All of the above.

Questions 54 and 55 refer to data given below:

A train runs at an average speed of 50 kmph between stations situated 2.5 km apart. The train accelerates at 2 kmph and retards at 3 kmph. Speed-time curve may be assumed to be trapezoidal.

54. The maximum speed is

(A) 27.75 kmph

(B) 38.50 kmph

(C) 44.25 kmph

(D) 57.75 kmph.

55. The distance traveled before the brakes are applied is

(A) 0.75 km

(B) 1.35 km

(C) 2.0 km

(D) 2.35 km.

56. At an average the coal consumption per km in case of steam engine is nearly

(A) 28 to 30 kg

(B) 80 to 100 kg

(C) 150 to 160 kg

(D) 200 to 250 kg.

57. Unbalanced forces are maximum in case of

(A) electric locomotive

(B) diesel locomotives

(C) Petrol locomotives

(D) steam locomotives.

58. Maintenance requirements are least in case of

(A) electric locomotives

(B) diesel locomotives

(C) steam locomotives.

59. If the resistance to electric train is given by

F_r = a + bv + cv²

In this equation constant c is likely to cover

(A) air resistance

(B) frictional resistance

(C)flange resistance

(D) track resistance.

60. The duration of acceleration is

(A) 32 sec

(B) 24 sec

(C) 16 sec

(D) 12 sec.

Questions 61 and 62 refer to data given below:

A train is required to run between two stations 16 km apart at an average speed of 43 kmph. The run is to be made to a simplified quadrilateral speed-time curve. The maximum speed is to be limited to 64 kmph, acceleration to 2 kmph and coasting and braking retardations to .16 and 3.2 kmph respectively.

61. The duration of costing is

(A) 48.4 sec

(B) 96.8 sec

(C) 12.35 sec

(D) 15.15 sec.

62. The braking period is

(A) 1.5 sec

(B) 5.15 sec

(C) 12.35 sec

(D) 15.15 sec.

63. When a locomotive for Railways is designated as WAM₁, in this the letter W indicates that

(A) the locomotive is to run on broad guage track

(B) the locomotive is to run on meter guage track

(C) the locomotive is for shunting duty

(D) the locomotive is for good train only

64. An ideal traction system should have

(A) high starting tractive effort

(B) equipment capable of withstanding large temporary overloads

(C) easy speed control

(D) all of the above.

Questions 65-66 refer tot he data given below:

A train runs at an average speed of 45 kmph between stations 2.5 km apart. The train accelerates at 2 kmph and retards at 3 kmph speed-time curve may be assumed to be trapezoidal.

65. The maximum speed attained will be nearly

(A) 80 kmph

(B) 60 kmph

(C)50 kmph

 (D) 1.535 kmph. 

66. The distance traveled before the brakes are applied is

(A) 2.383 km

(B) 2.103 km

(C) 1.887 km

(D) 35 kmph.

67. The main difference between speed-time curves of mainline service as compared to suburban services lies in

(A) longer free running periods

(B) longer coasting periods

(C) shorter acceleration gand braking periods

(D) all of the above.

Questions 68 to 70 refer to data given below:

An electric train is to have a braking retardation of 3.2 kmph. The ratio of maximum speed to average speed is 1.3, the time for stop is 26 seconds and acceleration is 0.8 kmph. The run is 1.5 km.

68. Actual time of run is

(A) 77 seconds

(B) 101 seconds

(C) 154 seconds

(D) 231 seconds.

69. The schedule time is

(A) 154 kmph

(B) 180 kmph

(C) 210 seconds

(D) 240 seconds.

70. The schedule speed is

(A) 25 kmph

(B) 30 kmph

(C) 45 kmph

(D) 60 kmph.

71. Energy consumption in propelling the train is required for

(A) acceleration

(B) work against gravity while moving up the gradient

(C) work against the resistance to motion

(D) all of the above.

72. Quadrilateral speed-time curve is the closer approximation for

(A) main line service

(B) suburban service

(C) urban service

(D) urban and suburban service.

73. Distance between the rails for meter gauge track is

(A) 2' - 6 3/8"

(B)3'-4 3/4"

(C) 4' - 6 1/2"

(D) One meter.

Questions 74 to 76 refer to data given below:

An electric train has quadrilateral speed time curve as follows:

(i) Uniform acceleration from rest at 2 kmph for 30 seconds

(ii) Coasting for 50 seconds

(iii) Uniform braking to rest for 20 seconds The train is moving a uniform up gradient of 1 in 100, train resistance is 40 N/tonne, rotational inertia effect 10% of dead weight and duration of stop 30 seconds.

74. Braking retardations is

(A) 0.87 kmphps

(B) 1.27 kmphs

(C) 1.87 kmphs

(D) 2 kmphps.

75. The distance traveled is

(A) 1.03 km

(B) 1.53 km

(C) 2.03 cm

(D) 2.53 cm.

76. Schedule time is

(A) 100 seconds

(B) 110 seconds

(C) 120 seconds

(D) 130 seconds.