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Suppose a motor is run at 1500 rpm and field rheostat is at minimum position (say 10Ω). Then the field rheostat resistance is increased to 100Ω and the speed obtained is 1700 rpm. Now the motor is shut down and started again. Will it now run at 1700 rpm?
My logic: No it won't, because:
the field current is less⇒starting torque is less⇒load torque is same⇒torque difference is less⇒acceleration is less⇒steady state speed is less.
Please correct me if I'm wrong.(I recently had an argument with my friend with whom I'm going to give a presentation on this method.He disagrees and my professor backed him.)
I don't understand how it will run at higher speed when started at lower field current. By that logic, at no field current, the motor should run at infinite speed. Am I missing something?
My logic: No it won't, because:
the field current is less⇒starting torque is less⇒load torque is same⇒torque difference is less⇒acceleration is less⇒steady state speed is less.
Please correct me if I'm wrong.(I recently had an argument with my friend with whom I'm going to give a presentation on this method.He disagrees and my professor backed him.)
I don't understand how it will run at higher speed when started at lower field current. By that logic, at no field current, the motor should run at infinite speed. Am I missing something?