Lesson 3
At what frequency does alternating current (AC) start propagating as a wave?
10 kHz is when AC emits radio frequencies.
What is the range of short wave frequencies that propagate as skywaves?
(3- 30 MHz).
What causes ions to develop in the ionosphere?
Ions are produced from the sun. Solar radiation ionizes ionosphere producing ions.
What happens is ultraviolet light from the sun collides with atoms in the ionoshpere knocking electrons loose. This creates ions, or atoms with missing electrons. This is what gives the Ionosphere its name. It is the free electrons that cause the reflection and absorption of radio waves. More here.
Sophie Neudorf 