91Ó°ÊÓ

The electromagnetic wave travels with the speed of light and as the frequency f of the wave is related to the wavelength and the speed as$\mathbf{c}\mathbf{=}\mathbf{´Úλ}$Thus,$\mathbf{λ}\mathbf{=}\frac{\mathbf{c}}{\mathbf{f}}$

The frequency is given by f =$110×{10}^6\mathrm{Hz}$ The frequency of the electromagnetic waves doesn't change with changing the medium while the wavelength changes as the speed of the light changes by the medium. The wavelength is

${\mathrm{λ}}_{\mathrm{air}}=\frac{\mathrm{c}}{\mathrm{f}}=\frac{3×{10}^8\mathrm{m}/\mathrm{s}}{110×{10}^6\mathrm{Hz}}=2.73\mathrm{m}$

The nodal planes of the magnetic field are apart with distance. Plug the values for to get l

$\mathrm{l}=\frac{\mathrm{λ}}{2}=\frac{2.73}{2}=1.36\mathrm{m}$

Therefore,${\mathrm{λ}}_{\mathrm{air}}=2.73\mathrm{m}$

For eight antinodes planes of the electric field, use equation$\mathrm{x}=\frac{8}{2}\mathrm{λ}$ to get the distance between adjacent nodal planes x which represents the length of the cavity. Substitute the values we have,

$\mathrm{x}=\frac{8}{2}(2.73\mathrm{m})=10.92\mathrm{m}$

Therefore, the distance between adjacent nodal planes x is 10.92m