# Solved Problems-5

Problem-5

Calculate the critical frequencies for the

*F*_{1},*F*_{2}and*E*layers for which the maximum ionic densities are 2.3 Ã— 10^{6}, 3.5 Ã— 10^{6}and 1.7 Ã— 10^{6}electrons per c.c. respectively.Solution

For the
So, the critical frequency,
For the
So, the critical frequency,
For the
So, the critical frequency,

*F*_{1 }layer,*N*_{max}= 2.3 Ã— 10^{6}cm^{-3 }= 2.3 Ã— 10^{6}Ã— 10^{6 }m^{-3 }= 2.3 Ã— 10^{12 }m^{-3}*F*_{2 }layer,*N*_{max}= 3.5 Ã— 10^{6}cm^{-3 }= 3.5 Ã— 10^{6}Ã— 10^{6 }m^{-3 }= 3.5 Ã— 10^{12 }m^{-3}*E*layer,*N*_{max}= 1.7 Ã— 10^{6}cm^{-3 }= 1.7 Ã— 10^{6}Ã— 10^{6 }m^{-3 }= 1.7 Ã— 10^{12 }m^{-3}