Electrical Machines A commutator with a diameter of 50 cm rotating at 1000 rpm. For a brush width of 1.5 cm, find the time of commutation in ms. 0.512. 0.649. 0.443. 0.573. 0.512. 0.649. 0.443. 0.573. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The damper windings also called the squirrel cage windings or damper grids are provided on the stator for improving power factor. are provided in a synchronous motor to make it self starting. both (A) and (B). consists of short-circuited copper bars embedded in the field pole faces. are provided on the stator for improving power factor. are provided in a synchronous motor to make it self starting. both (A) and (B). consists of short-circuited copper bars embedded in the field pole faces. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which of the following is done in speed control of DC motor by field flux control? Inserting resistance to armature circuit and field circuit. Inserting an additional resistance in the field circuit. Inserting an additional resistance in the armature circuit. Any of above. Inserting resistance to armature circuit and field circuit. Inserting an additional resistance in the field circuit. Inserting an additional resistance in the armature circuit. Any of above. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines For a DC machine having P no of pair of pole pairs, Z no of conductors having length L of resistivity ρ and cross section S are arranged. what is the armature resistance? PZL/4Sa² PZL/ 4Sa PZL/4S PZL/4Sp² PZL/4Sa² PZL/ 4Sa PZL/4S PZL/4Sp² ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Stability of a synchronous motor ---------- with the increase in excitation. decreases increases remains unaffected any of the above decreases increases remains unaffected any of the above ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines With the increase in speed of a DC motor both back emf as well as line current increase. back emf increases but line current falls. back emf falls and line current increases. both back emf as well as line current fall. both back emf as well as line current increase. back emf increases but line current falls. back emf falls and line current increases. both back emf as well as line current fall. ANSWER DOWNLOAD EXAMIANS APP
EXAMIANS