Renewable Energy Systems 2026 Physics Prep

1. What is the fundamental principle of a Photovoltaic (PV) cell? A) Conversion of thermal energy directly into electricity B) Conversion of light energy into electricity via the photovoltaic effect C) Conversion of mechanical energy into electricity D) Conversion of chemical energy into electricity Correct Answer: B) Conversion of light energy into electricity via the photovoltaic effect 2. The maximum theoretical efficiency of a single-junction solar cell is known as the: A) Carnot limit B) Shockley-Queisser limit C) Bethe-Salpeter equation D) Nernst limit Correct Answer: B) Shockley-Queisser limit 3. In a wind turbine, what is the Betz limit? A) The maximum speed a turbine can rotate B) The maximum theoretical efficiency of a wind turbine (approx. 59.3%) C) The maximum height a turbine can be built D) The wind speed at which a turbine must shut down Correct Answer: B) The maximum theoretical efficiency of a wind turbine (approx. 59.3%) 4. What is the primary source of heat in geothermal energy? A) Solar radiation trapped in the upper atmosphere B) Radioactive decay of isotopes within the Earth's mantle and core C) Friction from tectonic plate movement D) Chemical reactions in underground water Correct Answer: B) Radioactive decay of isotopes within the Earth's mantle and core 5. Which law of thermodynamics dictates that energy cannot be created or destroyed, only transformed? A) First Law of Thermodynamics B) Second Law of Thermodynamics C) Zeroth Law of Thermodynamics D) Third Law of Thermodynamics Correct Answer: A) First Law of Thermodynamics 6. What is the "Energy Density" of a battery? A) The total weight of the battery B) The amount of energy stored per unit volume or mass C) The speed at which it charges D) The number of times it can be recharged Correct Answer: B) The amount of energy stored per unit volume or mass 7. "Grid Parity" is achieved when: A) The energy grid collapses B) The levelized cost of electricity (LCOE) from renewable sources is equal to or less than the grid price of traditional power C) Two power plants produce equal amounts of energy D) The government sets the price of electricity Correct Answer: B) The levelized cost of electricity (LCOE) from renewable sources is equal to or less than the grid price of traditional power 8. What is the main benefit of "Pumped Hydro" storage? A) It uses very little space B) It allows for large-scale storage of energy by moving water between reservoirs at different elevations C) It requires no electricity to operate D) It can be built anywhere Correct Answer: B) It allows for large-scale storage of energy by moving water between reservoirs at different elevations 9. Which material is most commonly used as the semiconductor in PV cells? A) Copper B) Silicon C) Aluminum D) Silver Correct Answer: B) Silicon 10. What is "Direct Current" (DC)? A) Current that changes direction periodically B) Current that flows in only one direction C) Current that has no voltage D) Current used only in wind turbines Correct Answer: B) Current that flows in only one direction 11. What is an "Inverter" in a solar system? A) A device that makes the solar panels rotate B) A device that converts DC electricity from panels to AC electricity for the grid C) A device that stores electricity D) A device that increases the voltage of DC Correct Answer: B) A device that converts DC electricity from panels to AC electricity for the grid 12. "Alternating Current" (AC) is used in the national grid because: A) It is cheaper to produce B) It can be easily transformed to higher/lower voltages for efficient long-distance transmission C) It is safer for humans D) It doesn't require wires Correct Answer: B) It can be easily transformed to higher/lower voltages for efficient long-distance transmission 13. What defines the "Band Gap" in a semiconductor? A) The color of the material B) The energy difference between the valence band and the conduction band C) The physical distance between two panels D) The temperature of the material Correct Answer: B) The energy difference between the valence band and the conduction band 14. Which renewable energy source is most "dispatchable"? A) Solar B) Wind C) Geothermal D) Ocean waves Correct Answer: C) Geothermal 15. "Levelized Cost of Electricity" (LCOE) includes: A) Only the cost of construction B) The total cost of building and operating an energy plant over its lifetime divided by total energy generated C) Only the cost of fuel D) Only the maintenance cost Correct Answer: B) The total cost of building and operating an energy plant over its lifetime divided by total energy generated 16. What is "Power Factor" in an electrical system? A) The ratio of real power to apparent power B) The speed of the generator C) The cost of the power D) The total energy generated Correct Answer: A) The ratio of real power to apparent power 17. "Green Hydrogen" is produced via: A) Steam methane reforming B) Electrolysis of water using renewable electricity C) Coal gasification D) Nuclear heating Correct Answer: B) Electrolysis of water using renewable electricity 18. What is the role of the "Rotor" in a wind turbine? A) It holds the turbine steady B) It captures the kinetic energy of the wind and converts it into rotational energy C) It converts DC to AC D) It stores energy Correct Answer: B) It captures the kinetic energy of the wind and converts it into rotational energy 19. "Base load power" refers to: A) Energy that is never used B) The minimum amount of power required on the electrical grid at all times C) Energy produced only during the day D) Energy produced by solar panels only Correct Answer: B) The minimum amount of power required on the electrical grid at all times