Electrical Machines A single-phase transformer has its maximum efficiency at 60 percent of full load. At full load copper loss will be zero. less than core loss. equal to core loss. more than core loss. zero. less than core loss. equal to core loss. more than core loss. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A commutator in DC machines can 1. provide half-wave rectification 2. Provide full-wave rectification 3. convert ac to dc 4. Convert dc to ac 5. provide controlled full-wave rectification From these, the correct answer is 2, 3 ,5 1, 2, 3 2, 3, 4, 5 2, 3, 4 2, 3 ,5 1, 2, 3 2, 3, 4, 5 2, 3, 4 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a DC Shunt Motor the speed can be increased by Decreasing the field current. Increasing the field current. Increasing the field current. Increasing the armature current. Decreasing the field current. Increasing the field current. Increasing the field current. Increasing the armature current. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In dc machines, 1. reactance voltage is proportional to armature current 2.reactance voltage is proportional to core length 3.reactance voltage is due to self-flux of the coil undergoing commutation 4. armature-cross flux is neutralized by interpolar flux 5. interpolarmmf is more than armature mmf in the interpolar zone From these, the correct answer is 1, 2, 5 2, 3, 4 1, 2, 3, 4 1, 3, 5 1, 2, 5 2, 3, 4 1, 2, 3, 4 1, 3, 5 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The voltmeter connected across a generator reads voltage same at no load and at full load (rated). The generator is of the type level compound. shunt generator. short - shunt generator. series generator. level compound. shunt generator. short - shunt generator. series generator. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A DC shunt generator builds up to a voltage of 220 V at no load while running at its rated speed. If the speed of the generator is raised by 25% kepping the circuit conditions unaltered, then the Voltage to which the machine would build up will increase to 1.25 times 220 V increase to a value greater than 1.25 times 220 V increase to value lying between 220 V and 1.25 times 220 V not change and remain at 220 V increase to 1.25 times 220 V increase to a value greater than 1.25 times 220 V increase to value lying between 220 V and 1.25 times 220 V not change and remain at 220 V ANSWER DOWNLOAD EXAMIANS APP
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