Electrical Machines which of the following type of brush and their application is/are correct carbon brush → normal ratings All of these electro graphite → large ratings copper graphite → low voltage high current density carbon brush → normal ratings All of these electro graphite → large ratings copper graphite → low voltage high current density ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Two synchronous generators operating in parallel 200 MW and 400 MW respectively. The drooping characteristics of their governors are 4% and 5% from no load to full load. Consider the governors operating at 50Hz on no load. How will the machine share, if the load is 600 MW? generator 1 gets over load generator 2 gets over load None of these 200 MW and 400MW generator 1 gets over load generator 2 gets over load None of these 200 MW and 400MW ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines When a synchronous motor is running at synchronous speed, the damper winding produces eddy current torque. damping torqe. both 1 and 2. no torque. eddy current torque. damping torqe. both 1 and 2. no torque. 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. Cannot be predicted due to insufficient data. Would be equal to If1/2. Woud be equal to 2If1. Would be equal to If1. Cannot be predicted due to insufficient data. Would be equal to If1/2. Woud be equal to 2If1. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The power factor of an induction motor operating at no load will have a value around 0.9 lag unity 0.2 lead 0.2 lag 0.9 lag unity 0.2 lead 0.2 lag ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a DC series generator, the terminal voltage with increase in load will increase gradually and then stay at rated voltage increase to rated voltage and then may decrease remain nearly constant decrease increase gradually and then stay at rated voltage increase to rated voltage and then may decrease remain nearly constant decrease ANSWER DOWNLOAD EXAMIANS APP