Electromagnetic waves with frequency greater than the critical frequency of ionosphere cannot be used for communication using sky wave propagation, because:

Assertion : Electromagnetic waves with frequencies more than the critical frequency of ionosphere cannot be used for communication using sky wave propagation. Reason : The refractive index of the ionosphere becomes very high for frequencies higher than the critical frequency .

Statement-I : Electromagnetic waves with frequencies smaller than the critical frequency of ionosphere cannot be used for communication using sky wave propagation Statement-II : The refractive index of the ionosphere becomes very high for frequency.

Statement-I : Electromagnetic waves with frequencies smaller than the critical frequency of ionosphere cannot be used for communication using sky wave propagation Statement-II : The refractive index of the ionosphere becomes very high for frequency.

Assertion : Electromagentic waves with frequencies more than the cirtical frequency of ionosphere cannot be used for communication using sky wave propagation. Reason : The refractive index of the ionosphere becomes very high for frequencies higher than the critical frequency .

Statement-1 : Electromagnetic waves with frequencies smaller than the critical frequency of ionosphere cannot be used for communications using sky wave propagation. Statement-2: The refractive index of the ionosphere becomes very high for frequencies higher than the critical frequency.

Statement-1 : Electromagnetic waves with frequencies smaller than the critical frequency of ionosphere cannot be used for communications using sky wave propagation. Statement-2: The refractive index of the ionosphere becomes very high for frequencies higher than the critical frequency.

Statement-1 : Electromagnetic waves with frequencies smaller than the critical frequency of ionosphere cannot be used for communications using sky wave propagation. Statement-2: The refractive index of the ionosphere becomes very high for frequenceis higher than the criritcal frequency.