You are given a $25$kW$,230$V DC shunt motor with armature resistance, Ra$=0\mathrm{.}14.$ The no load speed of the motor at rated voltage is $1980$ rpm and armature current is $8\mathrm{.}2$ A$.$ The field resistance is $120.$ When the machine is operated at full load $($rated voltage$),$ its armature current is $160$ A but its flux is $7\mathrm{.}5\%$ less than the no load value.

$($i$)$

Sketch the diagram for the shunt connected motor, showing clearly the direction of armature current, and the field resistance $(2$mks$).$

$($ii$)$

Calculate the values of induced voltage, Ea$,$ for the no load and full load cases $(4$mks$).$

$($iii$)$

By using the ratio of voltages$/$ speeds and considering the flux decrease, determine the speed at full load $(3$mks$)($d$)$ You are given a $\backslash (25\backslash$mathrm$\{$~kW$\},230\backslash$mathrm$\{$~V$\}\backslash )$ DC shunt motor with armature resistance, $\backslash (\backslash$mathrm$\{$Ra$\}=0\mathrm{.}14\backslash$Omega $\backslash ).$ The no load speed of the motor at rated voltage is $1980$ rpm and armature current is $8\mathrm{.}2$ A $.$ The field resistance is $\backslash (120\backslash$Omega $\backslash ).$ When the machine is operated at full load $($rated voltage$),$ its armature current is $160$ A but its flux is $\backslash (7\mathrm{.}5\backslash \%\backslash )$ less than the no load value.

$($i$)$ Sketch the diagram for the shunt connected motor, showing clearly the direction of armature current, and the field resistance $(2$ mks $).$

$($ii$)$ Calculate the values of induced voltage, Ea$,$ for the no load and full load cases $(4$ mks $).$

$($iii$)$ By using the ratio of voltages$/$ speeds and considering the flux decrease, determine the speed at full load $(3$mks$)$