Electrical Machines A 4-pole DC generator runs at 1500 rpm. The frequency of current in the armature winding is: 25 Hz. 50 Hz. Zero Hz. 100 Hz. 25 Hz. 50 Hz. Zero Hz. 100 Hz. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The noise resulting from vibrations of lamination set by magnetic forces, is termed as boo. zoom. magnetostriction. hum. boo. zoom. magnetostriction. hum. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In case the conditions for maximum power for DC motor are established, the efficiency of the motor will be Around 90 % Any where between 75 % and 90 %. Around 100 %. Less than 50 % Around 90 % Any where between 75 % and 90 %. Around 100 %. Less than 50 % ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines An ideal synchronous motor has no starting torque because rotor is made up of salient poles. rotor winding is highly reactive. relative velocity between the stator and rotor mmf’s is zero. relative velocity between stator and rotor mmf’s is not zero. rotor is made up of salient poles. rotor winding is highly reactive. relative velocity between the stator and rotor mmf’s is zero. relative velocity between stator and rotor mmf’s is not zero. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines What is/are the necessary conditions for parallel operation of alternators? Frequency should be same Terminal voltage is same Speed of alternators should be same Both 1and 2 Frequency should be same Terminal voltage is same Speed of alternators should be same Both 1and 2 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If residual magnetism of a shunt generator is destroyed accidentally it may be restored by connecting its shunt field to earth. to a DC source. to an AC source. in reverse. to earth. to a DC source. to an AC source. in reverse. ANSWER DOWNLOAD EXAMIANS APP
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