Electrical Machines The frequency of voltage generated by an alternator having 8 poles and rotating at 250 rpm is 60 Hz. 16.67 Hz. 50 Hz. 25 Hz. 60 Hz. 16.67 Hz. 50 Hz. 25 Hz. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Two dc machines A and B, using the same conductor material, have armature circuit resistances of 0.4 Ω and 1.2 Ω respectively. Of the two machines, A is bigger than B for the same current rating A is bigger than B for the same voltage rating both are of the same size for the same current rating B is bigger than A for the same current rating A is bigger than B for the same current rating A is bigger than B for the same voltage rating both are of the same size for the same current rating B is bigger than A for the same current rating 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 there was no residual magnetism in the field circuit field winding was wrongly connected there was a break in the armature circuit field resistance was higher than critical resistance there was no residual magnetism in the field circuit field winding was wrongly connected there was a break in the armature circuit field resistance was higher than critical resistance ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a synchronous motor hunting can be reduced to minimum possible by using a flywheel. designing the motor for adequate synchronizing power. any of above methods. providing damper winding in the rotor pole faces. using a flywheel. designing the motor for adequate synchronizing power. any of above methods. providing damper winding in the rotor pole faces. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A dc shunt motor has external resistance Ra and Rf in the armature and field circuits respectively. Armature current at starting can be reduced by keeping Ra maximum and Rf minimum Ra minimum and Rf minimum Ra maximum and Rf maximum Rf maximum and Ra minimum Ra maximum and Rf minimum Ra minimum and Rf minimum Ra maximum and Rf maximum Rf maximum and Ra minimum ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A smaller air gap in a induction motor helps to reduce the chance of cogging. reduce the chance of crawling. increase the starting torque. reduce the magnetizing current. reduce the chance of cogging. reduce the chance of crawling. increase the starting torque. reduce the magnetizing current. ANSWER DOWNLOAD EXAMIANS APP