EX-503-A Electrical Power Generation and Economy - Dec 2025 Question Paper

Under each question, How to answer lists the points an answer should cover, outlined by CampusPrep from the syllabus. Check the details against your textbook.

1. 7 Marks
   aWhat factors are most important when choosing a location for a hydroelectric power plant?
   How to answer

   • Availability of water head, discharge and storage capacity
   • Geological, topographical and hydrological factors
   • Proximity to load centre, transport and cost of land
   • Environmental and rehabilitation considerations
2. 7 Marks
   bDescribe the various energy sources found in nature. Write the advantages of natural energy sources.
   How to answer

   • List natural sources: solar, wind, hydro, tidal, geothermal, biomass, fossil, nuclear
   • Classification renewable vs non-renewable
   • Advantages: clean, abundant, sustainable, low operating cost
   • Conservation of fossil fuels and environmental benefits
3. 7 Marks
   aState the classification of hydro-turbines based on the water head available, and describe the working of any one.
   How to answer

   • Classification by head: high head Pelton, medium head Francis, low head Kaplan
   • Head ranges and turbine type selection
   • Working principle of any one turbine with water flow path
   • Neat sketch and main components
4. 7 Marks
   bDescribe the flow and power duration curve of a hydroelectric plant.
   How to answer

   • Definition of flow duration curve from hydrological data
   • Construction of power duration curve as $P = \eta \rho g Q H$
   • Use for firm power and secondary power estimation
   • Illustrative curve shape with flow/power vs time
5. 7 Marks
   aDraw a typical layout of a steam plant. Explain the main features of the layout.
   How to answer

   • Neat layout showing boiler, turbine, condenser, pump, coal and ash handling
   • Steam, feed water, cooling water and electrical circuits
   • Main features: high efficiency, large capacity, site requirements
   • Function of major blocks in sequence
6. 7 Marks
   bDescribe in brief the components of a coal power plant -

   1. i)Feeding and burning,
   2. ii)Cooling tower, and
   3. iii)Ash handling
   How to answer

   • Feeding and burning: stokers, pulverized coal firing
   • Cooling tower: function, types and working
   • Ash handling: collection, removal and disposal
   • Need of each subsystem in coal plant operation
7. 7 Marks
   aExplain a high-pressure boiler with a neat sketch. Describe the construction, working principle, advantages, and applications of any one high-pressure boiler.
   How to answer

   • Neat sketch of selected high-pressure boiler e.g. Benson, La Mont
   • Construction details: drumless/forced circulation, tubes
   • Working principle and steam generation at high pressure
   • Advantages, limitations and applications
8. 7 Marks
   bWhat is non-conventional power generation? Write the advantages and limitations of non-conventional power generation.
   How to answer

   • Definition of non-conventional generation: solar, wind, tidal, geothermal
   • Advantages: renewable, pollution-free, decentralized
   • Limitations: intermittent, low density, high capital cost
   • Comparison with conventional sources
9. 7 Marks
   aExplain the Magneto-Hydro Dynamic (MHD) power generation system with a neat diagram. Write down its advantages, disadvantages, and applications.
   How to answer

   • MHD principle: conducting fluid in magnetic field generates emf
   • Neat diagram with plasma duct, magnets, electrodes
   • Advantages: high efficiency, no moving parts; disadvantages: high temperature materials
   • Applications: topping plant, space and peak load
10. 7 Marks
    bWrite short notes on-

    1. i)Direct energy conversion solar system
    2. ii)Direct energy conversion wind system
    How to answer

    • Direct solar conversion: photovoltaic effect, cell and array
    • Direct wind conversion: turbine-generator, power equation
    • Components and working of each system
    • Merits and uses
11. 7 Marks
    aWrite a note on the Economics of electrical power generation.
    How to answer

    • Cost components: fixed, semi-fixed and running costs
    • Factors affecting generation cost: load factor, diversity
    • Expression for cost per kWh and tariff basis
    • Measures for economic generation
12. 7 Marks
    bDistinguish between nuclear fusion and nuclear fission. What is the function of a moderator in a nuclear reactor?
    How to answer

    • Fusion vs fission: definition, fuel, conditions, energy release
    • Tabular differences on reaction, waste, control
    • Moderator function: slowing fast neutrons for fission
    • Examples of moderators: graphite, heavy water
13. 7 Marks
    aConsider two units of a plant that have fuel costs of $F1= 0.2P_1^2+40P_1+120$ Rs./h $F2=025P_2^2+30P_2+150$ Rs./h

    1. i)Determine the economic operating schedule and the corresponding cost of generation for the demand of 180 MW.
    2. ii)If the load is equally shared by both the units, determine the savings obtained by loading the units optimally.
    How to answer

    • Fuel cost curves $F1=0.2P_1^2+40P_1+120$, $F2=0.25P_2^2+30P_2+150$
    • Equal incremental cost criterion $dF1/dP1 = dF2/dP2$ with $P1+P2=180$ MW
    • Solve for $P1, P2$ and total cost Rs./h
    • Compare with equal sharing to find savings
14. 7 Marks
    bDescribe the procedure for the disposal of nuclear waste in short.
    How to answer

    • Sources and hazards of nuclear waste
    • Steps: cooling, shielding, reprocessing, conditioning
    • Short-term storage vs deep geological disposal
    • Safety and monitoring requirements
15. 7 Marks
    aThe maximum demand of a power plant is 50 MW. The capacity factor is 0.4 and the utilization factor is 0.8 Find:

    1. i)Load factor
    2. ii)Plant capacity
    3. iii)Reserve capacity
    4. iv)Annual energy production
    How to answer

    • Relations: utilization factor = max demand / plant capacity
    • Capacity factor = average load / plant capacity, load factor = average / max
    • Compute plant capacity, load factor, reserve capacity
    • Annual energy = capacity factor x plant capacity x 8760 h
16. 7 Marks
    bDescribe in brief-

    1. i)Economic scheduling principle,
    2. ii)Load forecasting, and
    3. iii)Electric tariffs
    How to answer

    • Economic scheduling principle: equal incremental cost
    • Load forecasting: need, methods short and long term
    • Electric tariffs: types, flat, block, two-part, TOD
    • Objectives of tariff and forecasting