A 10kW, 50 Hz, 3-phase induction motor develops the rated torque at 1440rpm. If the load torque is reduced to half, then the motor speed is?
(a) 1470rpm
(b) 1410rpm
(c) 1400rpm
(d) 1444rpm
I got this question in a national level competition.
My doubt is from Circle Diagrams of Induction Machines in section Induction Machines of Electrical Machines