Question

Speed torque characteristic of DC shunt motor is _______________

(a) Starting from origin

(b) Starting from speed axis and increasing

(c) Starting from speed axis and decreasing

(d) Starting from speed axis and constant

The question was posed to me in examination.

I'd like to ask this question from Operating Characteristics of DC Shunt Motor in division Characteristics of DC Motors of DC Machines

Answer 1

The correct answer is (c) Starting from speed axis and decreasing

The best I can explain: Speed-torque characteristic falls as torque increases, because armature reaction causes decrease in flux whose square is in inverse proportion with speed, causing decrease in speed rapidly compare to increase in torque.