Q$.$ The magnetization curve of the $6-kW,120-V,$ separately excited generator is given in table $1$ at $n_0=1000rpm.$ The machine is run at $1000rp{m}_{es}$ The armature and field winding resistances are $0\mathrm{.}25$ and $25$ respectively. $V_F=75V.$

a$.$ Determine the speed at which the generator is to be driven such that the full load voltage is $130V.($Take $R_{ad}=0.)$

b$.$ Determine the field current required to produce a terminal voltage of $120V$ at rated load current, and a speed of $926\mathrm{.}6re\frac{v}{m}in.$

$\backslash$table$[[$If$,$ A$,0\mathrm{.}5,1\mathrm{.}1,1\mathrm{.}75,2\mathrm{.}875,3\mathrm{.}0,4\mathrm{.}0,5\mathrm{.}2,6\mathrm{.}5],[$Ea$..,80,90,100,110,115,120,132,143],[$Table$1.,,,,,,,,]]$