Electrical Machines What is the frequency of a alternator, if P = number of poles and N = revolution made per second? 120N / P Hz. 120 / PN Hz. PN / 2 Hz. 120P / N Hz. 120N / P Hz. 120 / PN Hz. PN / 2 Hz. 120P / N Hz. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The material used for commutator brushes is mostly carbon. cast iron. mica. copper. carbon. cast iron. mica. copper. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Copper brushes in DC machine are used None of these where low voltage and high currents are involved. in both of above cases. where high voltage and low current. None of these where low voltage and high currents are involved. in both of above cases. where high voltage and low current. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Consider the following statements : For a level compounded dc generator to run at constant voltage, the series field mmf must effectively compensate 1. armature reaction mmf 2.armature resistance drop 3. brush contact voltage drop Which of these statements is/are correct ? 1, 2 and 3 1 and 2 2 alone 1 and 3 1, 2 and 3 1 and 2 2 alone 1 and 3 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If a DC Series motor is connected across an AC supply it will not run. run at lower speed. run at normal speed. burn. not run. run at lower speed. run at normal speed. burn. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If input of a transformer is square wave the output will be triangular wave. sine wave. square wave. pulsed wave. triangular wave. sine wave. square wave. pulsed wave. ANSWER DOWNLOAD EXAMIANS APP
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