Electrical Machines In case of a dc motor the ratio Eb / E is indicative of ratio of starting to running current. ratio of input to output voltage. efficiency. ratio of starting to running torque. ratio of starting to running current. ratio of input to output voltage. efficiency. ratio of starting to running torque. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If the applied voltage of a certain transformer is increased by 50% and the frequency is reduced by 50%, the maximum flux density will (assuming that the magnetic circuit remains unsaturated) changes to three times the original value changes to 1.5 times the original value changes to 0.5 times the original value remain the same as the original changes to three times the original value changes to 1.5 times the original value changes to 0.5 times the original value remain the same as the original ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Two generators G1 and G2 are to be operated in parallel to deliver a total current of 60 A. Generator one has a terminal voltage of 280 V on no load and 240 V when supplying 40 A current. Similarly the second generator has a voltage of 300 V when on no load and 240 V when supplying of 50 A of current. The output voltage of each generator will be 256.4 V. 271.7 V. 238.2 V. 240 V. 256.4 V. 271.7 V. 238.2 V. 240 V. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The armature mmf in a dc machine is 1. stationary with respect to field poles 2. stationary with respect to armature 3. rotating with respect to field poles 4. rotating with respect to armature From these, the correct answer is 1, 3 2, 3 1, 4 2, 4 1, 3 2, 3 1, 4 2, 4 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A motor armature conductor of length 0.5 m is exposed to a flux density of 4 Wb / m2. Calculate the force experienced by the conductor, when the armature current is 5 Amp? 20 N. Can't be determined. 15 N. None of these. 20 N. Can't be determined. 15 N. None of these. 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 Rf maximum and Ra minimum Ra maximum and Rf maximum Ra minimum and Rf minimum Ra maximum and Rf minimum Rf maximum and Ra minimum Ra maximum and Rf maximum Ra minimum and Rf minimum ANSWER DOWNLOAD EXAMIANS APP
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