About this previous year paper
SECTION A — Very Short Answers (2 Marks Each)
1. Fossil vs Non-Fossil Fuels
Fossil: Coal, oil, gas; finite; polluting Non-fossil: Solar, wind, hydro; renewable; eco-friendly
2. Materials used in Solar Cells
Silicon (mono & polycrystalline) Gallium arsenide
Cadmium telluride
3. Photovoltaic Cell
Device that converts solar energy directly into electrical energy using photovoltaic effect.
4. Solar Radiation
Electromagnetic energy emitted by the sun and received by Earth.
5. Geothermal Energy Resources
Heat energy stored beneath Earth’s crust in hot rocks, steam, and water.
6. Key Components of MHD Power Plant
Combustion chamber Magnetic field
Electrodes Power conditioning system
7. Electromagnetic Energy
Energy propagated as electric and magnetic waves (e.g., solar radiation).
8. Types of Wind Turbine Rotors
Single blade Two blade
Three blade
9. Sources of Biomass
Agricultural waste Animal dung
Municipal solid waste Forest residues
10. OTEC: Benefits & Drawbacks
Benefits: Renewable, clean, continuous Drawbacks: High cost, low efficiency
SECTION B — Short Notes / Analytical (10 Marks)
1. Role of Renewable Energy in Environmental Protection
Reduces greenhouse gas emissions Conserves fossil fuels
Promotes sustainable development Improves air quality
2. Flat Plate Solar Collector
Construction
Absorber plate Transparent cover
Insulation Fluid tubes
Performance Factors Solar intensity
Heat losses Flow rate
3. Magneto-Hydrodynamics (MHD)
Converts thermal energy directly into electricity
Ionized gas moves through magnetic field
No mechanical turbine required
4. Factors Affecting Thermoelectric Devices
Temperature difference Electrical conductivity
Material efficiency Contact resistance
5. Tidal Power Plants
Advantages
Predictable energy Renewable
Disadvantages
High capital cost Limited locations
SECTION C — Conceptual (10 Marks)
Renewable vs Non-Renewable Energy
| Renewable | Non-Renewable |
|---|---|
| Inexhaustible | Exhaustible |
| Clean | Polluting |
| Sustainable | Unsustainable |
Grid Integration Challenges (Solar)
Intermittency Voltage fluctuations
Storage requirement Grid stability issues
SECTION D — Solar Energy Applications (10 Marks)
Types of Solar Collectors Flat plate collectors
Evacuated tube collectors Concentrating collectors
Applications
Water heating Space heating
Industrial process heat Thermal Energy Storage
Sensible heat storage (water, stones) Latent heat storage (PCM)
SECTION E — Geothermal & Fuel Cell (10 Marks)
Geothermal Power Plant (Working) Hot water/steam extracted
Steam drives turbine Generator produces electricity
Condensate reinjected Fuel Cell Performance Factors
Operating temperature Pressure
Fuel purity Electrolyte quality
SECTION F — Wind & Thermoelectric Energy (10 Marks)
Types of Wind Turbines Horizontal Axis Wind Turbine (HAWT)
Vertical Axis Wind Turbine (VAWT) HAWT Working
Wind rotates blades Shaft drives generator
Electricity produced Seebeck Effect
Voltage produced due to temperature difference between two conductors.
SECTION G — Biomass & Ocean Energy (10 Marks)
Biomass Conversion Technologies Combustion
Gasification Pyrolysis
Anaerobic digestion Open-Cycle OTEC
Warm seawater → steam Steam drives turbine
Condensed by cold seawater