Electrical Machines In DC machine torque is proportional to which of the following? flux(φ) both A and B None of these armature current(Ia) flux(φ) both A and B None of these armature current(Ia) ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Capacitor start capacitor run provides high staring torque only. high staring torque and high power factor. none. high power factor only. high staring torque only. high staring torque and high power factor. none. high power factor only. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Under which of the following conditions is a dc motor provided with compensating winding used ? 1. Wide range of speed control above normal 2. Wide range of steady load variation with no speed control 3.Wide range of rapid variation in load Select the correct answer using the codes given below : Codes : 1 and 3 1 and 2 1, 2 and 3 2 and 3 1 and 3 1 and 2 1, 2 and 3 2 and 3 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Consider the following statements : Interpoles in dc machines 1. reducearmature reaction effects in the interpolar region 2. have the same dimension as main polls 3. have their windings connected in series with the armature 4. have same number of turns as the armature 5. have the polarity same as that of the main pole ahead in a motor From these, the correct statements are 1 and 3 1, 3 and 5 1, 2 and 3 1, 2, 3 and 5 1 and 3 1, 3 and 5 1, 2 and 3 1, 2, 3 and 5 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 Would be equal to If1/2. Would be equal to If1. Woud be equal to 2If1. Cannot be predicted due to insufficient data. Would be equal to If1/2. Would be equal to If1. Woud be equal to 2If1. Cannot be predicted due to insufficient data. 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 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 more with wave winding than with lap winding. Armature emf is less 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 more with wave winding than with lap winding. ANSWER DOWNLOAD EXAMIANS APP
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