Question

A 400 Volt DC shunt Machine takes 7 Amp at no-load when operates as a motor. The armature and field resistance are 0.25Ω and 200Ω respectively, when measured at room temperature. Calculate the efficiency of the machine: (i) When runs as a motor taking a line current of 70Amp at 400 Volt and (ii) When runs as a generator delivering a line current of 70Amp at 400 Volt The stray load loss is 1.1percent of the output. Neglect the increase in resistance due to temperature rise

Answer 1

Answer:

P=440 w v =220 v i 40 a hope this helps