A $200-V$ shunt motor develops an output of $17\mathrm{.}158$ kW when taking $20\mathrm{.}2$ kW $.$ The field resistance is $R_f=50$ and armature resistance is $R_a=0\mathrm{.}06.$

$($a$)$ Draw the equivalent circuit of the motor.

$($b$)($i$)$ Determine the input current of the motor, $I_t.$

$($ii$)$ Determine the field current, $I_f.$

$($iii$)$ Determine the armature current, $I_a.$

$($c$)($i$)$ Determine the total losses of the motor.

$($ii$)$ Determine the armature copper loss.

$($iii$)$Determine the constant losses of the motor.

$($d$)$ The output power is now $7\mathrm{.}46$ kW $.$

$($i$)$ Determine the new armature current.

$($iii$)$Determine the input power.

$($ii$)$ Determine the new input current, $I_t.$

$($iv$)$ Determine the efficiency.

PLEASE ANSWER ALL PARTS