The de machine in Problem $4\mathrm{.}3$ has a field control resistance whose value can be changed from $0$ to $15052.$ The machine is driven at $1200$ rpm$.$ The machine is separately excited, and the field winding is supplied from a $120$ V supply.$($a$)$ Determine the maximum and minimum values of the no$-$load terminal voltage.$($b$)$ The field control resistance $($Rf$)$ is adjusted to provide a no$-$load terminal voltage of $120$ V$.$Determine the value of Ri$.$ Determine the terminal voltage at full load for no armaturereaction and also if lAR$)=0\mathrm{.}1$ A$.$