The highest frequency that is returned to Earth when transmitted vertically under given ionospheric conditions is called the ____________.
A)critical angle
B)maximum usable frequency
C)critical frequency
D)optimum working frequency

Question

Quizplus · Accepted Answer

The highest frequency that is returned to Earth when transmitted vertically under given ionospheric conditions is called the critical frequency. This is a characteristic of the ionosphere's ability to reflect radio waves back to Earth.

The Highest Frequency That Is Returned to Earth When Transmitted