Question 1: Define a non-renewable energy resource and give two examples.

Answer: A non-renewable energy resource is an energy source that cannot be replenished naturally within a short period; examples include coal and nuclear fuel.

Question 2: Explain the main mechanism by which nuclear power plants generate electricity.

Answer: Nuclear power plants generate electricity through nuclear fission, where the nucleus of an atom, such as uranium-235, splits into smaller parts, releasing a large amount of energy used to produce steam that drives turbines.

Question 1: A coal-fired power station has an efficiency of 35%. If it consumes 500 kg of coal per hour, with the energy content of coal being 24 MJ/kg, calculate the electrical energy output per hour. Use the formula: Energy output = efficiency × total energy input.

Answer: Energy input per hour = 500 kg × 24 MJ/kg = 12,000 MJ; Energy output = 0.35 × 12,000 MJ = 4,200 MJ.

Question 2: If a nuclear reactor produces 3 GW of power continuously, how much energy is produced in a day? (1 GW = 1×10^9 W). Show your calculation.

Answer: Power = 3×10^9 W; Energy = Power × time = 3×10^9 W × 86,400 seconds = 2.592×10^14 Joules.

Question 1: Describe two safety precautions that should be taken when handling nuclear fuel.

Answer: Handling nuclear fuel requires precautions such as wearing protective clothing to prevent radiation exposure and ensuring proper storage in shielded containers to prevent contamination.

Question 2: Identify one variable that affects the efficiency of a coal-fired power station and explain how.

Answer: One variable is the quality of coal; higher-quality coal with higher energy content increases efficiency by providing more energy per unit mass.

Question 1: A country’s energy consumption from coal increased from 200 million tonnes in 2010 to 300 million tonnes in 2020. Calculate the percentage increase over this period. Show your working.

Answer: Percentage increase = [(300 - 200) / 200] × 100 = (100 / 200) × 100 = 50%.

Question 2: A report states that the average lifetime of a coal power plant is 40 years, and the current capacity utilisation is 75%. Discuss what this indicates about the plant’s operational status and potential future decommissioning.

Answer: This indicates that the plant has been operational for nearly its full expected lifetime with a relatively high utilisation rate, suggesting it is currently productive. However, as it approaches or exceeds 40 years, there may be plans for decommissioning or upgrading, especially considering environmental regulations and economic factors.

Question 1: Explain how the reliance on non-renewable energy sources like coal and oil impacts environmental pollution.

Answer: Reliance on coal and oil leads to air pollution through the release of greenhouse gases like carbon dioxide and pollutants such as sulphur dioxide, which contribute to climate change and acid rain.

Question 2: Discuss one technological advancement that could reduce the environmental impact of using non-renewable energy sources.

Answer: Carbon capture and storage (CCS) technology can capture CO2 emissions from fossil fuel power plants, reducing their impact on the environment.