Which is NOT one of the three paths a radio wave travels when transmitted from an antenna?

Which is NOT one of the three paths a radio wave travels when transmitted from an antenna?

• A. Surface Waves
• B. Space Waves
• C. Sky Waves
• D. Ground Waves

Answer: (D)

The main idea is that radio waves propagate in three primary ways: along the Earth's surface as surface (ground) waves, directly through space as space (line-of-sight) waves, and by reflecting off the ionosphere as sky waves. Surface waves and ground waves are the same phenomenon described with different terms. Because they are not separate propagation modes, listing ground waves as a distinct path would double-count the same mechanism. So ground waves isn’t a separate third path, making it the correct choice as not representing a distinct path.

The main idea is that radio waves propagate in three primary ways: along the Earth's surface as surface (ground) waves, directly through space as space (line-of-sight) waves, and by reflecting off the ionosphere as sky waves. Surface waves and ground waves are the same phenomenon described with different terms. Because they are not separate propagation modes, listing ground waves as a distinct path would double-count the same mechanism. So ground waves isn’t a separate third path, making it the correct choice as not representing a distinct path.