Electrical Machines If the full load speed of 3-phase, 50Hz induction motor is 950 rpm, what is its half load speed nearly equals to? 975 rpm 940 rpm 950 rpm 1000 rpm 975 rpm 940 rpm 950 rpm 1000 rpm ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If an induction machine is run at above the synchronous speed it acts as a synchronous motor an induction generator an induction motor None of these a synchronous motor an induction generator an induction motor None of these ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Eg (generated emf) and Eb (back emf) both are none of above. different. same. changes. none of above. different. same. changes. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In case of a dc motor the ratio Eb / E is indicative of efficiency. ratio of starting to running torque. ratio of input to output voltage. ratio of starting to running current. efficiency. ratio of starting to running torque. ratio of input to output voltage. ratio of starting to running current. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 3-φ alternator has negligible stator resistance. A short circuit test is conducted on this alternator. At a particular speed, a field current of If1 is required to drive the rated armature current. If the speed of the alternator is reduced to half, the field current required to maintain rated armature current Cannot be predicted due to insufficient data. Would be equal to If1. Would be equal to If1/2. Woud be equal to 2If1. Cannot be predicted due to insufficient data. Would be equal to If1. Would be equal to If1/2. Woud be equal to 2If1. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A delta/star transformer is connected in parallel to a star/delta transformer. The turn ratio former is x times latter, the x is 3 √3 1/3 1/√3 3 √3 1/3 1/√3 ANSWER DOWNLOAD EXAMIANS APP
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