Electrical Machines If s is the slip and f is the supply frequency of an induction motor, the frequency of rotor current is given by s2. f / s. sf / 2. sf. s2. f / s. sf / 2. sf. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 3-phase, alternator has generated emf per phase of 230 V with 10% 3rd harmonic and 6% 5th harmonic content. Calculate rms line voltage for star connection. 50 V. 230.2 V. 399 V. 100 V. 50 V. 230.2 V. 399 V. 100 V. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 220 V, DC shunt motor is operating at a speed of 1440 rpm. The armature resistance is 1.0 Ω and armature current is 10 A. of the excitation of the machine is reduced by 10%, the extra resistance to be put in the armature circuit to maintain the same speed and torque will be 1.8 9 Ω 3.1 Ω 2 .1 Ω 1.79 Ω 1.8 9 Ω 3.1 Ω 2 .1 Ω 1.79 Ω ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Cogging of induction motor occurs at high voltage and when stator and rotor poles are not equal. low voltage and when stator and rotor poles are not equal. high voltage and when stator and rotor poles are equal. low voltage and when stator and rotor poles are equal. high voltage and when stator and rotor poles are not equal. low voltage and when stator and rotor poles are not equal. high voltage and when stator and rotor poles are equal. low voltage and when stator and rotor poles are equal. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If an AC servomotor has one of its winding excited by AC, then voltage measured at the other winding with rotor running will be zero. proportional to rotor speed. proportional to square of rotor speed. constant independent of speed. zero. proportional to rotor speed. proportional to square of rotor speed. constant independent of speed. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The heat generated in the transformer is dissipated mainly by All of these radiation. conduction. convection. All of these radiation. conduction. convection. ANSWER DOWNLOAD EXAMIANS APP
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