Which of the following is true when a ray is incident normally in an Ionosphere region?
(a) MUF is equal to critical frequency
(b) MUF is greater than critical frequency
(c) MUF is less than critical frequency
(d) MUF is zero
I have been asked this question by my school teacher while I was bunking the class.
My query is from Maximum Usable Frequency in chapter Virtual Height, Critical Frequency and Muf of Antennas