Electrical Machines A generator may loose residual magnetism due to vibrations. heating. over excitation. any of these. vibrations. heating. over excitation. any of these. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines With the increase in speed of a DC motor back emf falls and line current increases. both back emf as well as line current fall. back emf increases but line current falls. both back emf as well as line current increase. back emf falls and line current increases. both back emf as well as line current fall. back emf increases but line current falls. both back emf as well as line current increase. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Consider the following statements regarding the magnetization characteristics of a dc generator : 1. It represents the variation of field flux with field current. 2. Variation of open-circuit terminal voltage with field current is independent of speed 3. It is non-linear from zero to rated field current 4. It helps to determine the critical field resistance at a given speed 5. It always starts from the origin Which of these statements are correct ? 3 and 5 2, 3 and 4 1, 2 and 5 1 and 4 3 and 5 2, 3 and 4 1, 2 and 5 1 and 4 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines What is the mechanical power developed by a DC series motor is maximum? Back emf is equal to half the applied voltage. Back emf is equal to applied voltage. None of above. Back emf is equal to zero. Back emf is equal to half the applied voltage. Back emf is equal to applied voltage. None of above. Back emf is equal to zero. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A separately excited DC motor has an armature resistance of 0.5 Ohm. The supply voltage is 250V. Armature current is 20A and the speed of rotation is 1500 rpm. Find the torque developed? Zero 16.55 Nm 15.6 Nm 15.28 Nm Zero 16.55 Nm 15.6 Nm 15.28 Nm ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Synchronous reactance of an alternator represents field winding reactance armature reactance and leakage reactance a reactance operating at synchronous speed All of these field winding reactance armature reactance and leakage reactance a reactance operating at synchronous speed All of these ANSWER DOWNLOAD EXAMIANS APP
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