Electrical Machines Hysteresis loss is proportional to f1.5. f2. f. f3. f1.5. f2. f. f3. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If iron loss and full load copper loss of any transformer are denoted by Pi and Pc, then the load corresponding to maximum efficiency is given by (Pi / Pc) × full Load. (Pi / Pc)2 × full Load. (Pi / Pc)0.5 × Full Load. (Pi / Pc)1.6 × full Load. (Pi / Pc) × full Load. (Pi / Pc)2 × full Load. (Pi / Pc)0.5 × Full Load. (Pi / Pc)1.6 × full Load. 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, 4, 5 1, 2, 3 2, 3, 4 2, 3 ,5 2, 3, 4, 5 1, 2, 3 2, 3, 4 2, 3 ,5 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Two 3-phase AC generators are such that one has twice the linear dimensions of the other. The field windings of each are excited to give identical sinusoidal air-gap flux density waveform. Both have the same number of stator slots and identical winding patterns. The conductor/slot in a big generator is K times that of the smaller one. The value of K to get equal no load voltage at same frequency is 1/2. 4. 8. 1/4. 1/2. 4. 8. 1/4. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The direction of generated emf in the armature coil of a DC machine is 1. the same as that of the current in a generator 2. the same as that of the current in a motor 3. opposite to that of the current in a generator 4. opposite to that of the current in a motor From these, the correct answer is 1, 3 1, 4 2, 3 2, 4 1, 3 1, 4 2, 3 2, 4 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 more with wave winding than with lap winding. Armature emf depends on weather the machine is running as a motor or generator. Armature emf is same as long as the flux density in the air gap remains the same. Armature emf is less with wave winding than with lap winding. Armature emf is more with wave winding than with lap winding. Armature emf depends on weather the machine is running as a motor or generator. Armature emf is same as long as the flux density in the air gap remains the same. Armature emf is less with wave winding than with lap winding. ANSWER DOWNLOAD EXAMIANS APP
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