Electrical Machines A 100 KVA transformer is operating at 60 Hz, 240 V supply. The same transformer is operating at 50 Hz, 200 V supply. The new rating is 50 KVA 83.33 KVA 100 KVA 123.3 KVA 50 KVA 83.33 KVA 100 KVA 123.3 KVA ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The magnetic field which initially induces emf in the armature in a self excited DC generator is because of armature reaction. residual magnetism. permanent magnets. None of these armature reaction. residual magnetism. permanent magnets. None of these ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The core flux in transformer depends mainly on supply voltage supply voltage, frequency and load supply voltage and load supply voltage and frequency supply voltage supply voltage, frequency and load supply voltage and load supply voltage and frequency ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines To control the speed of an induction motor, the supply frequency is reduced by 10%. For the same magnetizing current to remain constant, the supply voltage must be increased by 10% increased by 20% reduced by 10% reduced by 20% increased by 10% increased by 20% reduced by 10% reduced by 20% ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a transformer which of the following losses are zero? Copper loss Iron loss Rotational loss All of these Copper loss Iron loss Rotational loss All of these ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If the load current and flux of a DC motor are held constant and voltage applied across it armature is increased by 5%, the speed of the motor will Remain unchanged. Increase by 5%. Reduce by 5%. Depends on other factor. Remain unchanged. Increase by 5%. Reduce by 5%. Depends on other factor. ANSWER DOWNLOAD EXAMIANS APP
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