Why this topic is important for ECET?
Power Generation methods form the core of Electrical & Electronics Engineering. ECET 2026 ECE students must understand the working principles, efficiency, advantages, and limitations of different power plants. Nuclear and Gas power plants are frequently asked in ECET exams because they test both basic concepts and practical applications. Questions often appear in the form of efficiency, fuel usage, advantages/disadvantages, or problem-solving on thermal efficiency.
📘 Concept Notes
1. Nuclear Power Plants
- Basic Principle: Energy is released by nuclear fission of heavy atoms like Uranium-235 or Plutonium-239.
- Working:
- Fission reaction in reactor → releases heat.
- Heat produces steam → rotates turbine.
- Turbine drives alternator → generates electricity.
Key Components:
- Reactor Core (fuel rods of U-235, moderator like heavy water, control rods of cadmium/boron)
- Heat Exchanger (transfers heat to coolant)
- Steam Turbine & Generator
Advantages:
- Huge energy from small fuel.
- No greenhouse gas emission.
- Suitable for base-load generation.
Disadvantages:
- High initial cost.
- Radioactive waste disposal problem.
- Nuclear accidents are dangerous (Chernobyl, Fukushima).
2. Gas Power Plants
- Basic Principle: Based on Joule/Brayton Cycle. Fuel (natural gas/diesel) is burned in a combustion chamber → hot gases expand → turbine rotates.
Working Steps:
- Air compressed → combustion chamber.
- Fuel injected, combustion occurs → high-temperature gas.
- Gas expands in turbine → mechanical power.
- Turbine drives generator → electrical power.
Advantages:
- Low initial cost.
- Quick start and shut down.
- Compact size.
Disadvantages:
- High operating cost (fuel expensive).
- Less efficient than steam/nuclear.
- Not suitable for base-load; used for peak load.
3. Comparison (Exam Point of View)
| Feature | Nuclear Power Plant | Gas Power Plant |
|---|---|---|
| Fuel | Uranium, Plutonium | Natural Gas, Diesel |
| Efficiency | 30–35% | 25–30% |
| Initial Cost | Very High | Low |
| Running Cost | Low | High |
| Start-up Time | Very slow | Very quick |
| Usage | Base load | Peak load |
⚙️ Formulas
- Thermal Efficiency:
Nuclear Energy Released:
Brayton Cycle Efficiency (Gas Turbine):
Where:
= Pressure ratio
= Ratio of specific heats (Cp/Cv)
🔟 10 MCQs
Q1. Which fuel is commonly used in nuclear power plants?
a) Coal
b) Uranium-235
c) Natural Gas
d) Diesel
Q2. In a nuclear reactor, control rods are used for:
a) Moderating neutrons
b) Absorbing neutrons
c) Cooling reactor
d) Producing steam
Q3. Efficiency of nuclear power plants is usually:
a) 10–15%
b) 20–25%
c) 30–35%
d) 50–60%
Q4. Gas power plants operate on which cycle?
a) Rankine
b) Brayton
c) Otto
d) Carnot
Q5. Which is NOT an advantage of gas power plants?
a) Quick start
b) Low running cost
c) Compact size
d) Simple design
Q6. Calculate energy released if 1g of Uranium undergoes complete fission.
(
, 
)
a) 
b) 
c) 
d) 
Q7. Gas power plants are mainly used for:
a) Base load
b) Peak load
c) Emergency load only
d) Continuous 24×7 load
Q8. In Brayton cycle, efficiency increases with:
a) Decreasing pressure ratio
b) Increasing pressure ratio
c) Constant pressure
d) Constant temperature
Q9. Which of the following is NOT a component of a nuclear power plant?
a) Control Rods
b) Moderator
c) Combustion chamber
d) Reactor core
Q10. Major disadvantage of nuclear power is:
a) High fuel cost
b) High maintenance cost
c) Radioactive waste
d) Low efficiency
✅ Answer Key
| Q.No | Answer |
|---|---|
| 1 | b |
| 2 | b |
| 3 | c |
| 4 | b |
| 5 | b |
| 6 | a |
| 7 | b |
| 8 | b |
| 9 | c |
| 10 | c |
🧠 Explanations
- Q1: Nuclear plants use Uranium-235/Plutonium-239 → (b).
- Q2: Control rods absorb neutrons to regulate fission → (b).
- Q3: Typical efficiency is 30–35% → (c).
- Q4: Gas plants work on Brayton (Joule) cycle → (b).
- Q5: Running cost is HIGH, so (b) is not advantage.
- Q6:
→ (a). - Q7: Gas plants are for peak load → (b).
- Q8: Higher pressure ratio = more efficiency → (b).
- Q9: Combustion chamber belongs to gas plant, not nuclear → (c).
- Q10: Nuclear waste disposal = biggest disadvantage → (c).
🎯 Motivation / Why Practice Matters
In ECET 2026 ECE, questions from Power Generation are direct and scoring. Mastering Nuclear and Gas plants helps you quickly answer MCQs on efficiency, fuel, usage, and disadvantages. Practicing daily improves your speed in identifying the correct option within seconds, giving you a competitive edge over others.
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