Q$\mathrm{.}4)(25$ points$)$ A shunt excited DC motor operated with terminal voltage of $240$ V and terminal current of $40$ A $.$ Its armature resistance is $\backslash (0\mathrm{.}2\backslash$Omega $\backslash )$ and its field resistance is $\backslash (196\backslash$Omega $\backslash ).$ Its saturation curve at $1500$ RPM is given below.

a$)$ Find the output power,

b$)$ Find its speed of operation,

c$)$ Find its torque.