Electrical Machines High inrush of current during a starting of DC motor can efficiently be restricted to a safer value by increasing the _________________ resistance. both A and B shunt field none of above armature circuit both A and B shunt field none of above armature circuit ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The armature resistance of a permanent magnet dc motor is 0.8 Ohm. At no load, the motor draws 1.5 A from a supply voltage of 25 V and runs at 1500 rpm. The efficiency of the motor while it is operating on load at 1500 rpm drawing a current of 3.5 A from the same source will be 59.2%. 57.1%. 48.0%. 88.8%. 59.2%. 57.1%. 48.0%. 88.8%. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The direction of rotation of a DC motor can be determined by Ampere's law. Fleming's right hand rule. Lenz's law. Fleming's left hand rule. Ampere's law. Fleming's right hand rule. Lenz's law. Fleming's left hand rule. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The armature reaction mmf in a DC machines has a form of sinusoidal. triangular. trapezoidal. rectangular. sinusoidal. triangular. trapezoidal. rectangular. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Consider the following statements regarding dc machines : 1. possible resistance of shunt-field winding is 1 Ω 2. possible resistance of series-field winding is 1 Ω 3. electrographite brushes are used for 230 V, 10 A machines 4. Copper-graphite brushes are used for 230 V, 10 A machines 5. Possible armature-circuit resistance is 1 Ω From these, the correct statements are 2, 4 ,5 1, 4 1, 3, 5 2, 3 , 5 2, 4 ,5 1, 4 1, 3, 5 2, 3 , 5 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines For a DC machine having P no of pole pairs, Z no of conductors having length L of resistivity ρ and cross section S are arranged. what is the armature resistance for simple wave-winding ? PZL/4S PZL/4Sa² PZL/ 4Sa PZL/4Sp² PZL/4S PZL/4Sa² PZL/ 4Sa PZL/4Sp² ANSWER DOWNLOAD EXAMIANS APP