Electrical Machines In auto transformer if the turn ratio is K, what is the power transferred inductively? both A and B (1-K) × input power K × input power None of these both A and B (1-K) × input power K × input power None of these ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Armature reaction in a DC machine is in the same direction as the main poles. makes an angle of 90° with the main pole axis. makes an angle with the main pole axis which is load dependent. is in direct opposition to the main poles. is in the same direction as the main poles. makes an angle of 90° with the main pole axis. makes an angle with the main pole axis which is load dependent. is in direct opposition to the main poles. 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 3 only 1, 2 and 3 1, 3 1, 2, 3 and 4 3 only 1, 2 and 3 1, 3 1, 2, 3 and 4 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The brushes of a DC machine should be placed on the commutator in the inter polar axis. commutator in the polar axis. armature midway between poles. armature in the polar axis. commutator in the inter polar axis. commutator in the polar axis. armature midway between poles. armature in the polar axis. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The frequency of voltage generated by an alternator having 8 poles and rotating at 250 rpm is 50 Hz. 60 Hz. 16.67 Hz. 25 Hz. 50 Hz. 60 Hz. 16.67 Hz. 25 Hz. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Under which of the following conditions hunting of synchronous motor is likely to occur ? Over-excitation. Over-loading for long period. Periodic variation of load. Small and constant load. Over-excitation. Over-loading for long period. Periodic variation of load. Small and constant load. ANSWER DOWNLOAD EXAMIANS APP
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