Question

Consider the following statements:

1. The ionosphere overlaps with part of the thermosphere.

2. It plays no role in long-distance radio communication.

Which of the above is/are correct?

• A. 1 only
• B. 2 only
• C. Both 1 and 2
• D. Neither 1 nor 2

Answer 1

Answer:

A. 1 only

• 
  

• Correct Answer: Option A) 1 only

• The ionosphere is a region of Earth's upper atmosphere that extends from approximately 60 km to 1,000 km above the Earth's surface

• Statement 1: The ionosphere overlaps with part of the thermosphere - correct

• The ionosphere does indeed overlap with part of the thermosphere. The thermosphere extends from about 80-85 km to 600-700 km altitude, while the ionosphere spans from about 60 km to 1,000 km. This means there is significant overlap between these two atmospheric layers, particularly in the altitude range of 80-600 km.

• Statement 2: It plays no role in long-distance radio communication - incorrect

• This statement is completely false. The ionosphere plays a crucial role in long-distance radio communication. The ionosphere contains ionized particles (free electrons and ions) that can reflect certain radio waves back to Earth. This phenomenon, known as "skip" or "skywave propagation," allows radio signals to travel far beyond the horizon by bouncing off the ionospheric layers. This is particularly important for:

• AM radio broadcasting

• Amateur (ham) radio communication

• International shortwave broadcasting

• Maritime and aviation communication

• The ionosphere's ability to reflect radio waves is what makes global radio communication possible without satellites.