(a) A shunt-wound motor set was designed to run from a 250 V d.c. supply. It had an effective armature resistance of 3 m Ohm and when run at 3000 rev/min it drew 10 kA.
(i) The maximum permissible supply voltage at start-up if the motor set is not to draw more than 20 kA when started from rest.
(ii) The maximum start-up torque available.
Please refer to the attached file for the solution.
I hope it helps.
Solution for Posting #2090
Shunt DC Motor
(i). When the motor start from the rest, the speed is zero, i.e., m = 0 ...
The solution is to be used more like guidance. It does not give numerical computation, but just formula wise computation.