Question 1: Explain why radio waves are used for broadcasting radio and television signals.

Answer: Radio waves have long wavelengths that can travel long distances and penetrate buildings, making them ideal for broadcasting signals over large areas.

Question 2: What is the main reason infrared waves are used in remote controls for televisions and other devices?

Answer: Infrared waves are used because they can transmit signals without interfering with other wireless communications and are safe for human exposure.

Question 3: Fill in the blank: Ultraviolet light is useful in sterilization because it can __________ bacteria and viruses.

Answer: destroy

Question 4: Describe one practical use of X-rays in medicine.

Answer: X-rays are used in medicine to create images of bones and internal organs, helping doctors diagnose injuries and diseases.

Question 5: Which type of electromagnetic wave is primarily used in microwave ovens to heat food?

Answer: Microwaves

Question 6: Calculate the energy in joules of a photon of visible light with a wavelength of 500 nm. (Use the formula: E = hc/λ, where h = 6.626 x 10^-34 Js, c = 3.00 x 10^8 m/s).

Answer: E = (6.626 x 10^-34 Js)(3.00 x 10^8 m/s) / (500 x 10^-9 m) = 3.97 x 10^-19 Joules

Question 7: Identify two safety precautions to consider when using ultraviolet light in sterilization procedures.

Answer: Wear protective goggles to prevent eye damage and limit skin exposure to UV radiation.

Question 8: Describe how gamma rays are used in cancer treatment.

Answer: Gamma rays are used in cancer treatment through a process called radiotherapy, where high-energy gamma radiation is directed at cancerous cells to destroy or damage their DNA, thereby killing the cells or stopping their growth. This targeted approach helps to eliminate tumors while minimizing damage to surrounding healthy tissues.

Question 9: Explain how the use of ultraviolet light in sterilization benefits everyday life.

Answer: Ultraviolet light sterilizes surfaces and equipment by killing bacteria and viruses, reducing the spread of infections in hospitals, water treatment, and food packaging.

Question 10: Identify one technological application of infrared waves outside of remote controls.

Answer: Infrared waves are used in thermal imaging cameras to detect heat patterns and diagnose electrical or mechanical issues.

Question 11: Discuss the importance of understanding the uses of the electromagnetic spectrum in everyday technology.

Answer: Understanding the uses of the electromagnetic spectrum allows scientists and engineers to develop and improve various technologies such as medical imaging, communications, cooking appliances, and security systems. It also helps in assessing safety precautions and environmental impacts of different waves used in daily life.