Question $1$: $[40$ pts$]$

A cellphone is placed inside a wooden drawer and is radiating RF signal while connecting to a Wi$-$Fi router placed outside the drawer. The cellphone and the Wi$-$Fi router are positioned such that their line$-$of$-$sight connecting the devices is normal to the intermediate wall of the drawer. This implicates that the incident EM wave is falling normally to the wall of the drawer.

Given that the dielectric constant of the wood in the drawer is $\backslash (\backslash$epsilon$\_\{$r$\}=12\backslash ),$ find the fractional electromagnetic power passing through the wooden wall. Free space$/$air$\text{'}$s impedance is provided as $\backslash (\backslash$eta$\_\{0\}=120\backslash$pi $\backslash$Omega $\backslash ),$