Answer Happy

A separately-excited brushed DC motor is supplied with voltage V (volts dc) and draws current I (amperes). The motor has its back emf E, armature resistance Ra back emf constant K, and torque constant Kr. Its performance can be summarised in the following figure Motor Speed Wy Rated operating point No load speed Torque-Speed Curve Sta cument Max. No load Stall torque Torque load Tri Select the correct statement among the following choices The no-load speed can be obtained as: wo E-R,I Ko O At the maximum output power, the motor torque is half of the stall torque, i.e. 0.5Trt- O At the maximum efficiency, the motor speed is a half of the no-load speed, i.e. 0.5V K, The stall armature current is Irt = KT O At the rated current, the motor speed is about half of the no-load speed, i.e. 0.500 Max power