A) small kW output rating B) variable speed C) high speed D) constant speed. Ans : (A)
A) air friction only B) both hysteresis and eddy current losses C) hysteresis loss only D) eddy current loss only. Ans : (B)
A) armature copper losses equal constant losses B) stray losses equal constant losses C) field copper losses are equal to armature copper losses D) magnetic losses are equal to mechanical losses. Ans : (A)
A) high initial cost B) poor overall efficiency C) high maintenance cost D) all of the above. Ans : (D)
A) 0.1 Ω B) 10 Ω C) 50 Ω D) 100 Ω. Ans : (A)
A) zero or very low supply voltage B) over-load C) high field circuit resistance D) all of the above. Ans : (D)
A) to step the motor B) to reduce the armature current of motor C) to reduce the motor speed D) to increase the motor speed. Ans : (D)
A) voltage control B) field control C) armature control D) none. Ans : (C)
A) armature only B) pole shoe only C) yoke only D) in all the above three. Ans : (A)
A) mechanical losses B) magnetic or iron losses C) shunt field copper loss D) armature copper loss. Ans : (D)