Electrical Machines Interpoles in a DC motor must be Series excited and should have the same polarity as that of the ahead main pole in the direction of rotation of armature. Series excited and should have the same polarity as that of the behind main pole in the direction of rotation of armature. Shunt excited and should have the same polarity as that of the ahead main pole in the direction of rotation of armature. Shunt excited and should have the same polarity as that of the behind main pole in the direction of rotation of armature. Series excited and should have the same polarity as that of the ahead main pole in the direction of rotation of armature. Series excited and should have the same polarity as that of the behind main pole in the direction of rotation of armature. Shunt excited and should have the same polarity as that of the ahead main pole in the direction of rotation of armature. Shunt excited and should have the same polarity as that of the behind main pole in the direction of rotation of armature. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines For a standard frequency the machine operates at a particular speed known as slip speed. normal speed. synchronous speed. any of the above. slip speed. normal speed. synchronous speed. any of the above. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The mechanical power is developed by a DC motor is maximum when back emf is equal to half of applied voltage. none of above. back emf is equal to applied voltage. back emf is equal to twice of applied voltage. back emf is equal to half of applied voltage. none of above. back emf is equal to applied voltage. back emf is equal to twice of applied voltage. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The shaft torque of a dc motor is less than the electromagnetic torque because of hysteresis losses. mechanical losses. eddy current losses. ohmic losses. hysteresis losses. mechanical losses. eddy current losses. ohmic losses. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a DC machine, for the same value of Æ, Z and N; which one of the following statements is correct? Armature emf is less with wave winding than with lap winding. Armature emf is more with wave winding than with lap winding. Armature emf is same as long as the flux density in the air gap remains the same. Armature emf depends on weather the machine is running as a motor or generator. Armature emf is less with wave winding than with lap winding. Armature emf is more with wave winding than with lap winding. Armature emf is same as long as the flux density in the air gap remains the same. Armature emf depends on weather the machine is running as a motor or generator. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Armature reaction in DC generators will result in short circuit. reduction in generated emf. increase in slip. open circuit. short circuit. reduction in generated emf. increase in slip. open circuit. ANSWER DOWNLOAD EXAMIANS APP