h2 N(h) E 1" A uniform plane electromagnetic wave of frequency f= 5MHZ emitted by an antenna at the earth's surface is incident normally on a layer of the ionosphere whose concentration of free electrons can be approximated by the following linear function of the latitude above the earth's surface: (h – h,) N(h) = No (h2 – h1) For hjShSh2, where h=100 km, h=200 km and NF 5 x 10'' m³. Find the highest altitude h reached by the wave, at which it bounces off and returns to the antenna.

h2 N(h) E 1" A uniform plane electromagnetic wave of frequency f= 5MHZ emitted by an antenna at the earth's surface is incident normally on a layer of the ionosphere whose concentration of free electrons can be approximated by the following linear function of the latitude above the earth's surface: (h – h,) N(h) = No (h2 – h1) For hjShSh2, where h=100 km, h=200 km and NF 5 x 10'' m³. Find the highest altitude h reached by the wave, at which it bounces off and returns to the antenna.