Electrical Machines In a 3 - Φ IM with line frequency f1 and winding factor kw1 and kw2 for stator and rotor respectively the ratio of per phase stator winding emf E1 to per phase rotor winding emf E2 at standstill is given by E1 / E2 = 1. E1 / E2 = N1kw1 / N2kw2. E1 / E2 = N1 / N2. E1 / E2 = f1kw1 / f2kw2. E1 / E2 = 1. E1 / E2 = N1kw1 / N2kw2. E1 / E2 = N1 / N2. E1 / E2 = f1kw1 / f2kw2. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which of the following generators are used in arc welding? series generators cumulative compound generators shunt generators differential compound generators series generators cumulative compound generators shunt generators differential compound generators ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The breakdown torque of a synchronous motor varies as applied voltage V 1/V 1/V² V² applied voltage V 1/V 1/V² V² ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A DC series motor must started on no load because it would Not develop starting torque. Draw more current without producing sufficient torque. Run at dangerously high speed. Fail to start without load. Not develop starting torque. Draw more current without producing sufficient torque. Run at dangerously high speed. Fail to start without load. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In DC machine, the armature windings are placed on the rotor because of necessity for development of torque. commutation. electromechanical energy conversion. generation of voltage. development of torque. commutation. electromechanical energy conversion. generation of voltage. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Consider the following statements about commutating poles which are fitted on most large dc Shunt motors: 1. The commutating poles are placed in the geometric neutral plane and their number is usually Equal to the number of main poles 2. The winding on the commutating poles is connected in series with the shunt-field winding on the main poles 3. The polarity of the commutating pole must be that of the next pole further ahead 4. The commutating poles neutralize the reactance voltage produced in the coil undergoing Commutation. Of these statements, 1, 2 and 4 are correct 2, 3 and 4 are correct 1, 2 and 3 are correct 1 and 4 are correct 1, 2 and 4 are correct 2, 3 and 4 are correct 1, 2 and 3 are correct 1 and 4 are correct ANSWER DOWNLOAD EXAMIANS APP