Question 1: Explain briefly how solar panels utilise the electromagnetic spectrum to generate electricity.

Answer: Solar panels convert visible light and some infrared radiation from the Sun into electrical energy using the photovoltaic effect.

Question 2: Which part of the electromagnetic spectrum is primarily used in solar thermal collectors for heating water?

Answer: Infrared radiation

Question 3: Fill in the blank: Renewable energy technologies such as wind turbines and solar panels convert electromagnetic waves into __________ energy.

Answer: electrical

Question 4: Describe the role of ultraviolet (UV) radiation in sterilising water using UV purification systems. (2 marks)

Answer: UV radiation kills bacteria and viruses by damaging their DNA, making it useful for sterilising water without chemicals.

Question 5: Calculate the energy of a photon of visible light with a wavelength of 500 nm. (Use the formula E = hc/λ, where h = 6.63 x 10⁻³⁴ Js, c = 3.00 x 10⁸ m/s).

Answer: E = (6.63 x 10⁻³⁴ Js)(3.00 x 10⁸ m/s) / (500 x 10⁻⁹ m) = 3.98 x 10⁻¹⁹ Joules

Question 6: Identify which part of the electromagnetic spectrum is most effective for remote sensing in environmental monitoring.

Answer: Infrared

Question 7: Long Answer (6 Marks): Discuss the advantages and limitations of using infrared radiation in solar thermal energy systems. Include at least two points for each.

Answer: Advantages include efficient heating and the ability to operate in cloudy conditions; limitations involve lower efficiency during night or low sunlight and potential heat loss due to infrared radiation escaping.

Question 8: Describe a basic experimental setup to measure the wavelength of infrared radiation emitted by a hot object, including the variables that need to be controlled.

Answer: Use an infrared spectrometer to detect emitted radiation from a hot object; control variables such as temperature, distance, and environmental conditions to ensure accurate measurements.

Question 9: In the context of renewable energy, explain how the use of microwave radiation is related to wireless power transmission. (2 marks)

Answer: Microwave radiation can transfer energy wirelessly from a transmitter to a receiver, enabling remote power transmission without cables, useful for powering devices in hard-to-reach areas.

Question 10: Based on current trends, suggest a future renewable energy technology that could utilise a different part of the electromagnetic spectrum and justify your choice.

Answer: Terahertz radiation could be used in advanced imaging or wireless data transfer in renewable energy systems due to its ability to penetrate materials and carry high data rates.