Question

Electromagnetic waves with frequencies greater than the critical frequency of ionosphere cannot be used for communication using sky wave propagation. because:
(a) the refractive index of the ionosphere becomes very high for $f\ \textgreater \ f_{c}}$
(b) the refractive index of the ionosphere becomes very low for $f\ \textgreater \ f_{c}}$
(c) the refractive index of the ionosphere very high for $f\ \textless \ f_{c}}$
(d) none of the above

Answer 1

For a Given system $\dot{x}_1 = x_1^2+x_2-2, \dot{x}_2=x_1+x_2$ Explain clearly Input - Output linearization and Input state linearization.