About this previous year paper
SECTION A
(2 × 10 = 20 marks | Short Answers)
a) Energy
Energy is the capacity to do work. It exists in different forms such as thermal, mechanical, electrical, chemical, and nuclear energy.
b) Conventional and non-conventional energy resources
Conventional: Coal, oil, natural gas, nuclear, hydro
Non-conventional: Solar, wind, biomass, tidal, geothermal
Non-conventional sources are renewable and eco-friendly.
c) Governing in steam power plants
Governing controls the speed and power output of the turbine by regulating steam flow.
Methods: Throttle governing
Nozzle control governing Bypass governing
Combination governing
d) Diesel power plant – advantages & disadvantages
Advantages: Quick start
Low installation cost Suitable for small power
Disadvantages: High fuel cost
Limited capacity More maintenance
e) Nuclear reactor
A nuclear reactor is a device where controlled nuclear fission takes place to produce heat for power generation.
f) Function of superheater
A superheater increases the temperature of saturated steam, improving efficiency and reducing turbine blade erosion.
g) Principle of wind energy conversion
Wind energy is converted into mechanical energy using a turbine, which is then converted into electrical energy using a generator.
h) Advantages of MHD power generation
High efficiency No moving parts
Less pollution Faster response
i) Particulate emission & gaseous pollutants
Particulate emission consists of solid or liquid particles released into the atmosphere.
Gaseous pollutants concentration is expressed in ppm or mg/m³.
j) Generator
A generator converts mechanical energy into electrical energy based on electromagnetic induction.
SECTION B
(Attempt any 3 | 10 marks each)
a) Why electrical energy is most convenient
Electrical energy is easy to generate, transmit, control, and convert into other forms with high efficiency and minimal losses.
b) Hydroelectric power plant
It converts potential energy of water into electrical energy using turbines and generators.
Applications: Base load supply
Irrigation support Flood control
c) Radioactive decay, half-life, moderating power
Radioactive decay: Spontaneous disintegration of unstable nuclei
Half-life: Time required for half the nuclei to decay
Moderating power: Ability of a material to slow down neutrons
Moderating ratio: Effectiveness of a moderator considering absorption
d) Geothermal power plant
It uses heat from earth’s interior to generate steam for power production.
Steam rotates the turbine connected to a generator. It is renewable and reliable.
e) Cooling of transformers
Air cooling Oil natural cooling
Forced oil and air cooling Water cooling
Cooling prevents overheating and insulation failure.
SECTION C
Q3 (Attempt any one)
a) Types of power plants & future energy trends
Types: Thermal
Hydroelectric Nuclear
Gas turbine Solar and wind
Future trends focus on renewable energy, hybrid systems, energy storage, and reduced carbon emissions.
b) Layout of modern thermal power plant
Main components: Boiler
Turbine Condenser
Cooling tower Generator
Feedwater system
Coal is burned to produce steam, which drives the turbine and generator.
Q4 (Attempt any one)
a) Reheating, intercooling & regeneration in gas turbines
Reheating: Increases turbine output Intercooling: Reduces compressor work
Regeneration: Uses exhaust heat to improve efficiency
These processes improve overall plant performance.
b) Combined steam and gas turbine power plant
Exhaust heat from gas turbine is used to produce steam for steam turbine, improving overall efficiency and reducing fuel consumption.
Q5 (Attempt any one)
a) Nuclear reactor & moderator
Main components: Fuel rods
Moderator Control rods
Coolant Shielding
Moderator function: Slows down fast neutrons.
Light materials like graphite or heavy water are used because they absorb fewer neutrons.
b) Solar thermal energy
It uses solar radiation to produce heat, which generates steam for power.
Advantages: Renewable, clean
Disadvantages: High initial cost, weather dependent
Applications: Power plants, water heating
Q6 (Attempt any one)
a) Wind electric generating system
Components: Rotor blades
Gearbox Generator
Tower Controller
It converts wind energy into electrical energy.
b) Spring tides and neap tides
Spring tides: High tidal range during full/new moon
Neap tides: Low tidal range during quarter moon
Tidal power schemes include single basin and double basin systems.
Q7 (Attempt any one)
a) Generator construction & cooling
Main parts: Stator
Rotor Shaft
Cooling system
Cooling is required to remove heat losses and prevent insulation damage.
b) Power plant pollutants & health effects
Pollutants: SO₂, NOₓ, CO₂
Fly ash Particulates
Effects: Respiratory problems
Eye irritation Global warming
DONE: ALL SEM VII SUBJECTS – SECTION-WISE
You now have: HVAC Systems
Mathematical Modeling of Manufacturing Processes
Machine Learning Maintenance Engineering & Management
Power Plant Engineering