Which energy source primarily relies on the conversion of sunlight into electricity using semiconductors?

A. Wind Energy

B. Geothermal Energy

C. Solar Energy

D. Tidal Energy

What is a primary environmental concern associated with hydroelectric dams?

A. Air pollution

B. Habitat destruction

C. Nuclear waste

D. Greenhouse gas emissions

Which energy source involves harnessing heat from the Earth's core?

A. Solar Energy

B. Biomass

C. Geothermal Energy

D. Wind Energy

Which of the following is NOT a type of fossil fuel?

A. Coal

B. Oil

C. Uranium

D. Natural Gas

What is the primary challenge associated with wind energy?

A. Radioactive waste

B. Intermittency

C. Greenhouse gas emissions

D. Habitat destruction

a) A photovoltaic cell with an efficiency of 20% is exposed to sunlight with an intensity of 600 W/m^2. Calculate the power output per square metre of the cell. [2]

b) If the cell has an area of 1.5 m^2, determine the total power output of the cell. [2]

a) A wind turbine with a blade length of 50 m rotates at 15 revolutions per minute (rpm). Calculate the linear speed of the tip of the blade. [2]

b) If the wind speed is 12 m/s, and the turbine operates at 40% efficiency, determine the power extracted from the wind by the turbine. Assume air density to be 1.225 kg/m^3. [2]

a) A geothermal plant extracts 5000 kg of steam per hour from the Earth's core at a temperature of 400°C and uses it to heat water from a river at 20°C. Calculate the heat energy transferred from the steam if its specific heat capacity is 2.1 J/g°C. [2]

b) If the geothermal plant operates at an efficiency of 30%, determine the useful energy output from the extracted heat. [2]

a) Explain the working principle of photovoltaic cells in converting sunlight into electricity. [3]

b) What challenges are faced in terms of energy storage for solar farms? [2]

c) Calculate the energy output of a solar farm if it has an efficiency of 20% and receives sunlight with a power of 600 W/m^2 over an area of 2000 m^2 for 5 hours. [3]

a) Describe the environmental impact of wind farms. [3]

b) If a wind turbine has a blade length of 50m, calculate the swept area of the turbine. [2]

c) Given that the air density is 1.225 kg/m^3 and the wind speed is 10 m/s, calculate the power available in the wind that can be harnessed by the turbine. [3]

Which energy source involves the controlled splitting of atomic nuclei?

A. Solar Energy

B. Nuclear Energy

C. Biomass

D. Tidal Energy

Which of the following is a benefit of using biomass for energy production?

A. It is non-renewable.

B. It produces large amounts of greenhouse gases.

C. It can be sourced from organic waste.

D. It requires large land areas.

What is the primary force harnessed in tidal energy?

A. Solar radiation

B. Wind currents

C. Gravitational forces of the Moon and Sun

D. Heat from the Earth's core

Which energy source has the primary challenge of radioactive waste disposal?

A. Solar Energy

B. Wind Energy

C. Geothermal Energy

D. Nuclear Energy

Which of the following is NOT a benefit of geothermal energy?

A. Low greenhouse gas emissions

B. Renewable source

C. Requires sunlight

D. Consistent energy production

a) Explain the mechanism by which geothermal plants extract and utilise energy from the Earth's core. [3]

b) What are the environmental benefits of using geothermal energy? [2]

c) A geothermal plant extracts 5000 kg of steam at 250°C from the Earth's core every hour. If the specific heat capacity of steam is 2.0 J/g°C, calculate the energy extracted in kWh. [3]

a) Differentiate between the environmental impacts of coal and natural gas when used as energy sources. [3]

b) If a coal power plant burns 1000 tonnes of coal in a day with an energy content of 24 MJ/kg, calculate the total energy produced in a day. [2]

c) Given that the efficiency of the power plant is 40%, calculate the usable energy output in kWh. [3]

a) Describe how hydroelectric dams generate electricity. [3]

b) What are the primary environmental considerations when constructing a hydroelectric dam? [3]

c) A hydroelectric dam has a water reservoir with a height of 150m. If water flows through the dam at a rate of 500 m^3/s, calculate the potential energy of the water. (Use g = 9.81 m/s^2) [3]

d) Given an efficiency of 85% for the dam, determine the electrical power output. [3]

a) Explain the principles of nuclear fission and how it is used to generate electricity. [4]

b) List two challenges associated with nuclear energy production. [2]

c) If a nuclear reactor uses 5 kg of uranium-235 in a day and releases energy at a rate of 200 MeV per fission event, calculate the total energy produced in a day. (Note: 1 MeV = 1.6 x 10^-13 J) [3]

d) Given that the efficiency of the nuclear reactor is 33%, calculate the usable energy output in kWh for the day. [3]

a) Describe the mechanism behind the greenhouse effect. [3]

b) List two major greenhouse gases and their sources. [2]

c) If the concentration of carbon dioxide in the atmosphere increases by 50 ppm in a decade, calculate the percentage increase. (Assume the initial concentration is 400 ppm) [3]

d) Discuss the potential impact of this increase on global temperatures. [4]