Electrical Machines Which of the following is not a necessary condition to be satisfied for synchronising an incoming alternator to an already operating alternator? same frequency same phase sequence same voltage magnitude same prime mover speed same frequency same phase sequence same voltage magnitude same prime mover speed ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines What is/are the necessary conditions for voltage build up in self excited generator? Field winding resistance should be less than critical resistance. Field winding should be properly connected to armature winding. All of these Poles should contain residual flux. Field winding resistance should be less than critical resistance. Field winding should be properly connected to armature winding. All of these Poles should contain residual flux. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Number of tappings for each equalizer ring is equal to number of commutator segments. number of pole pairs. number of poles. number of parallel paths. number of commutator segments. number of pole pairs. number of poles. number of parallel paths. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Wave winding is prefered for which of the following rating? high current and low voltage low current and low voltage high current and high voltage low current and high voltage high current and low voltage low current and low voltage high current and high voltage low current and high voltage ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 3-φ alternator has negligible stator resistance. A short circuit test is conducted on this alternator. At a particular speed, a field current of If1 is required to drive the rated armature current. If the speed of the alternator is reduced to half, the field current required to maintain rated armature current Would be equal to If1. Woud be equal to 2If1. Cannot be predicted due to insufficient data. Would be equal to If1/2. Would be equal to If1. Woud be equal to 2If1. Cannot be predicted due to insufficient data. Would be equal to If1/2. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines When R2 is rotor resistance, X2 the rotor reactance at supply frequency and s the slip, then the condition for maximum torque under running condition will be sR2 = X2. R2 = s2X2. R2 = sX2. R2 = s2X2. sR2 = X2. R2 = s2X2. R2 = sX2. R2 = s2X2. ANSWER DOWNLOAD EXAMIANS APP