Electrical Machines In DC generators brushes are used for reduce eddy current loss convert ac armature current in to dc collecting of current without any sparkings collecting of voltage reduce eddy current loss convert ac armature current in to dc collecting of current without any sparkings collecting of voltage ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A dc shunt generator, when driven without any excitation, showed an open circuit voltage of 12 V. When the field winding was excited, the voltage dropped to zero. It happened because field winding was wrongly connected field resistance was higher than critical resistance there was a break in the armature circuit there was no residual magnetism in the field circuit field winding was wrongly connected field resistance was higher than critical resistance there was a break in the armature circuit there was no residual magnetism in the field circuit ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines How can the synchronous speed of a 3 - Φ IM be varied? By varying supply voltage. Both (A) and (B). By varying the supply frequency. By varying number of poles. By varying supply voltage. Both (A) and (B). By varying the supply frequency. By varying number of poles. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Maximum power will be developed when back emf is double the supply voltage. half of the supply voltage. equal to supply voltage. All of these double the supply voltage. half of the supply voltage. equal to supply voltage. All of these ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Magnetic field of a DC generator is produced by what? Both B and C. Electromagnets. Permanent magnets. None of the options. Both B and C. Electromagnets. Permanent magnets. None of the options. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In synchronous generator a synchronous dead load (lamp, furnaces etc) has no ____________ hence it has no natural frequency of oscillation. damping torque. synchronizing power co efficient. mechanical rotatory system. restoring torque. damping torque. synchronizing power co efficient. mechanical rotatory system. restoring torque. ANSWER DOWNLOAD EXAMIANS APP
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