Question

Which segment of the electromagnetic wave spectrum is primarily used in line-of-sight radar systems for aircraft navigation and to cook food inside kitchen appliances?

• A. \( \text{Infrared Waves} \)
• B. \( \text{Microwaves} \)
• C. \( \text{Ultraviolet Rays} \)
• D. \( \text{Radio Waves} \)

Hint:

If a question mentions radar navigation or satellite communication, the answer is almost always microwaves. Traditional radio waves have wavelengths that are too long for precise radar mapping applications.

Answer 1

The Correct Option is B

Concept: The electromagnetic spectrum is organized into bands with specific frequencies that determine how they interact with matter. This makes different bands suitable for distinct technological applications.

Step 1: Match microwave properties to radar and communication networks. Microwaves have short wavelengths falling within the millimeter to centimeter range (frequencies between \( 1\,\text{GHz} \) and \( 300\,\text{GHz} \)). Because of their short wavelengths, they travel in clean, narrow line-of-sight beams without experiencing significant diffraction around everyday obstacles. This precision makes them ideal for aircraft radar detection networks and satellite communications.

Step 2: Analyze the heating mechanism used in microwave appliances. The specific frequency of microwaves inside kitchen appliances matches the natural resonant frequencies of water molecules. When these waves pass through food, the alternating electric field causes water molecules to flip back and forth rapidly. This intense molecular friction transfers thermal energy directly throughout the food, heating it up quickly.