Electrical Machines The armature core of the rotor bars of dc motors are laminated to reduce mechanical losses. to reduce hysteresis loss. to provide better flux linkage. to reduce eddy current loss. to reduce mechanical losses. to reduce hysteresis loss. to provide better flux linkage. to reduce eddy current loss. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Neglecting all losses, the developed torque (T) of DC separately excited motor, operating under constant terminal voltage is reduced to its output power (P) as T ∝ √P. T ∝ P. T2 ∝ P3. T is independent of P. T ∝ √P. T ∝ P. T2 ∝ P3. T is independent of P. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 4 pole DC shunt generator having a wave winding supplies 50 lamps, each of 60 W at 120 V. The armature and field resistance are 0.2 Ω and 60 Ω respectively. The current in each armature conductor is 11.5 A. 13.5 A. 23 A. 27 A. 11.5 A. 13.5 A. 23 A. 27 A. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines DC motors are stopped by opening line switches and not by forcing the handle of the motor starter back to OFF position. This is due to occurance of None of these. Heavy sparking at the first stud of starting resistance steps. Both of above. Heavy sparking at brushes. None of these. Heavy sparking at the first stud of starting resistance steps. Both of above. Heavy sparking at brushes. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines When the excitation of normally operating unloaded, salient pole synchronous motor suddenly gets disconnected, it continues to run as a switched reluctance motor. induction motor. variable reluctance motor. DC motor. switched reluctance motor. induction motor. variable reluctance motor. DC motor. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines What is/are the necessary conditions for parallel operation of alternators? Speed of alternators should be same Frequency should be same Both 1and 2 Terminal voltage is same Speed of alternators should be same Frequency should be same Both 1and 2 Terminal voltage is same ANSWER DOWNLOAD EXAMIANS APP