Q$7)(6$ Marks$)7\mathrm{.}1)(2$ Marks$)$ State three differences between waveguides and transmission lines:

$($a$)$

$($b$)$

$($c$)$

$7\mathrm{.}2)(4$ Marks$)$ A $2-$m$-$long center$-$fed dipole antenna operates in the AM broadcast band at $1$ MHz $.$ The dipole is made of copper wire with a radius of $1$ mm $.$

$($a$)$ Determine the radiation resistance of the antenna. $(1$ marks$)$

$($b$)$ What antenna current is required so that the antenna will radiate an average power of $100$ W $.(1$ marks$)$

Explanation $($Steps to find the answers$)$: $(2$ Marks$)$