Final Questions — All-Book

All chapters together · Total: 60 marks

A. Fill in the blanks (8 × 1 = 8 marks)

1. A generator makes electricity by moving a near a coil of wire.
2. Energy (kWh) = Power (kW) × (hours).
3. The boundary between n-type and p-type silicon is called the p–n .
4. Wind power depends on the of wind speed.
5. In a hydro plant, the steep pipe to the turbine is the .
6. Rods that absorb neutrons in a reactor are rods.
7. Splitting water with electricity is called .
8. India aims for 100 GW of nuclear capacity by .

B. True or False (8 × 1 = 8 marks)

1. A solar cell makes alternating current directly. ( ___ )
2. Doubling wind speed gives eight times the power. ( ___ )
3. Pumped storage returns all the energy used to pump the water. ( ___ )
4. A power reactor can explode like an atom bomb. ( ___ )
5. A fuel-cell bus releases water vapour. ( ___ )
6. India reached 20% ethanol blending in petrol in 2025. ( ___ )
7. An electric car is cleanest when charged from solar power. ( ___ )
8. Coal still makes most of the electricity India actually uses. ( ___ )

C. Choose the correct option (8 × 1 = 8 marks)

1. India’s grid frequency is (a) 50 Hz (b) 60 Hz (c) 100 Hz
2. A 2 kW heater used for 4 hours uses (a) 2 kWh (b) 6 kWh (c) 8 kWh
3. Common solar panels are about (a) 5% (b) 20% (c) 90% efficient
4. The theoretical maximum a wind turbine can capture is about (a) 29% (b) 59% (c) 99%
5. India’s first nuclear power station is at (a) Tarapur (b) Kalpakkam (c) Kudankulam
6. The Prototype Fast Breeder Reactor started its chain reaction in (a) 2016 (b) 2021 (c) 2026
7. India’s first commercial hydrogen buses run in (a) Leh (b) Mumbai (c) Jaipur
8. A 40 kWh EV battery at 0.16 kWh/km gives a range of (a) 64 km (b) 250 km (c) 640 km

D. Match the columns (6 × 1 = 6 marks)

E. Short answers (7 × 2 = 14 marks)

1. Explain why almost all power stations use a turbine and generator, and name the exception.
2. A 3 kW rooftop gets 5.5 peak sun hours. Estimate its monthly output (0.8 losses, 30 days).
3. Wind speed rises from 5 m/s to 10 m/s. By what factor does the available power change? Show your working.
4. Estimate the power of a hydro plant with a 60 m head and 15 m³/s flow at 90% efficiency.
5. List two advantages and two challenges of nuclear power.
6. What is green hydrogen, and why is it not yet widely used?
7. Explain why storage is needed as India adds more solar power.

F. Long answers — any TWO (2 × 8 = 16 marks)

1. Your district must add clean power for 50,000 homes. Compare at least three options from this book and recommend a mix, giving reasons and trade-offs.
2. Write a balanced newspaper article titled “Should India build more nuclear power plants?”
3. Choose any two stories from this book. Explain the science in each and the human side of the energy choice involved.
4. Plan an energy audit and clean-energy upgrade for your school, with numbers for use, solar size and savings.