Electrical Machines The armature of DC machine is made of silicon steel lamination to reduce eddy current loss only. increase the permeability. reduce both eddy current and hysteresis loss. reduce hysteresis loss only. reduce eddy current loss only. increase the permeability. reduce both eddy current and hysteresis loss. reduce hysteresis loss only. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Value of specific electric loading of Induction motor is in the range of 5000 - 45000 ampere conductor / metre. 40 - 400 ampere conductor / metre. 30000 - 100000 ampere conductor / metre. 400 - 4000 ampere conductor / metre. 5000 - 45000 ampere conductor / metre. 40 - 400 ampere conductor / metre. 30000 - 100000 ampere conductor / metre. 400 - 4000 ampere conductor / metre. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A DC shunt generator builds up 230 V when driven in clockwise direction. In case it is driven in anti clockwise direction, other things remaining unchanged, then the voltage build up is not possible 230 V some what more than 230 V some what less than 230 V not possible 230 V some what more than 230 V some what less than 230 V ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 250 volt dc series motor having an armature resistance of 0.2 Ω takes a load current of 60 A. What will be the torque produced at the shaft of the motor? Consider brush drop of 1V. 133.22 N-m 266.20 N-m. 234.76 N-m. can not be determined. 133.22 N-m 266.20 N-m. 234.76 N-m. can not be determined. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A self-excited shunt generator fails to build up, because 1. the field circuit is open 2. The armature circuit is open 3. the residual magnetism is absent 4. The direction of rotation is wrong From these, the correct answer is 3 only 1, 2, 3 and 4 1, 2 and 3 1, 3 3 only 1, 2, 3 and 4 1, 2 and 3 1, 3 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines What is the necessity of copper brushes in a dc motors? To increase the flux cutting by the rotor. None of these. To absorb the mechanical shocks produced during running condition. To convert alternating supply current to direct current. To increase the flux cutting by the rotor. None of these. To absorb the mechanical shocks produced during running condition. To convert alternating supply current to direct current. ANSWER DOWNLOAD EXAMIANS APP
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