Question

The part of the electromagnetic spectrum which is suitable for radar systems used in aircraft navigation.

• A. X - Rays
• B. Gamma Rays
• C. Microwaves or short radio waves
• D. Ultraviolet

Answer 1

The correct option is C

Microwaves or short radio waves

Explanation for correct option:

1. Microwaves or short radio waves are suitable for radar systems used in aircraft navigation because of their short wavelengths.
2. Microwaves are sometimes thought to be extremely short radio waves (high-frequency and high-energy radio waves).
3. Metallic surfaces reflect them.
4. They heat materials if they can make their atoms or molecules vibrate.
5. Microwaves are a type of electromagnetic radiation with wavelengths ranging from about one meter to one millimeter, corresponding to frequencies ranging from 300 MHz to 300 GHz.

Hence, Option(C) is correct.

Explanation for incorrect options:

1. X-radiation is a form of electromagnetic radiation. They are powerful waves of electromagnetic energy. Most of them have a wavelength ranging from 0.01 to 10 nanometers.
2. The X-Ray beam travels through the air and comes in contact with the body tissues, and produces an image on a metal film.
3. Gamma-rays are high-frequency electromagnetic radiation and therefore carry a lot of energy. They pass through most types of material. Only something really hard like a lead block or a thick concrete block can stop their transmission.
4. UV rays lie in the wavelength range from around 10 nm to around 400 nm and have a frequency between the ranges 800 THz to 30 PHz. UV radiation is harmful as continuous exposure to it will result in skin and eye diseases. It also results in the aging of the skin.

Hence, options (A), (B), and (D) are incorrect and (C) is the correct answer.