Electrical Machines To achieve spark less commutation brushes of DC generator are rocked ahead so as to bring them just behind the magnetic neutral axis. None of these just ahead of magnetic neutral axis. in magnetic neutral axis. just behind the magnetic neutral axis. None of these just ahead of magnetic neutral axis. in magnetic neutral axis. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The armature resistance of a permanent magnet dc motor is 0.8 Ohm. At no load, the motor draws 1.5 A from a supply voltage of 25 V and runs at 1500 rpm. The efficiency of the motor while it is operating on load at 1500 rpm drawing a current of 3.5 A from the same source will be 57.1%. 88.8%. 59.2%. 48.0%. 57.1%. 88.8%. 59.2%. 48.0%. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Alternator operates on the principle of self or mutual induction. mutual induction. electromagnetic induction. self induction. self or mutual induction. mutual induction. electromagnetic induction. self induction. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which of the following represents the pitch factor? Cos (α/2) Cos α Cos α² sin (α/2) Cos (α/2) Cos α Cos α² sin (α/2) ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines For a given torque, reducing diverter resistance of a DC series motor causes increase in speed demanding more armature current. decrease in speed demanding less armature current. decrease in speed but armature current remains the same. increase in speed but armature currnet remains the same. increase in speed demanding more armature current. decrease in speed demanding less armature current. decrease in speed but armature current remains the same. increase in speed but armature currnet remains the same. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If the full load speed of 3-phase, 50Hz induction motor is 950 rpm, what is its half load speed nearly equals to? 1000 rpm 940 rpm 950 rpm 975 rpm 1000 rpm 940 rpm 950 rpm 975 rpm ANSWER DOWNLOAD EXAMIANS APP