Electrical Machines Find the reactance voltage when current is changed from -2A to 2A in 4 sec and self inductance is 1H? 1 V 2 V 4 V 0 V 1 V 2 V 4 V 0 V ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If the load current and the flux of a DC motor are held constant and voltage applied across its armature is increased by 5%, the speed of the motor will depend on other factors. remain unchanged. increase by 5 %. reduce by 5 %. depend on other factors. remain unchanged. increase by 5 %. reduce by 5 %. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A self-excited shunt generator fails to build up, because 1. the field circuit is open 2. The armature circuit is open 3. the residual magnetism is absent 4. The direction of rotation is wrong From these, the correct answer is 1, 3 1, 2, 3 and 4 1, 2 and 3 3 only 1, 3 1, 2, 3 and 4 1, 2 and 3 3 only ANSWER DOWNLOAD EXAMIANS APP
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 Which of the following is/are the advantages of carbon brush over the copper brush? In case of any sparking they will be less damaged than copper brushes All of these They are not hard as copper brush They are self lubricating in nature In case of any sparking they will be less damaged than copper brushes All of these They are not hard as copper brush They are self lubricating in nature ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The rotor speed of an induction motor is given by Nr = 120f / p × (1-s). Ns = 120f / p × ( 1 - s ). None of these Ns = 120f /p × ( 1 - r). Nr = 120f / p × (1-s). Ns = 120f / p × ( 1 - s ). None of these Ns = 120f /p × ( 1 - r). ANSWER DOWNLOAD EXAMIANS APP
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