Question

What is the maximum usuable frequency (in MHz) for E-layer of atomosphere having critical frequency 4 MHz, when the angle of incidence is `60^(@)`

Answer 1

Here, `v_(C)=4MHz, i=60^(@)`
Maximum usuable frequency `=v_(C)` sec i
`=4xxsec 60^(@)=4xx2`
`=8 MHz`