Electrical Machines A 4-pole dc generator runs at 1500 rpm. The frequencyof current in the armature winding is 25 Hz 0 Hz 50 Hz 100 Hz 25 Hz 0 Hz 50 Hz 100 Hz ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A transformer core is made up of a silicon steel laminations which has maximum flux density 1 Tesla. If it was cold rolled grain oriented its flux density increases to 1.6 Tesla. What is the saving in core size or area due to cold rolled grain oriented process? 60% 68% 38% 40% 60% 68% 38% 40% ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A separately-excited dc motor has an armature resistance of 0.5 Ω. It runs off a 250 V dc supply Drawing an armature current of 20 A at 1500 rpm. The torque developed for an armature current Of 10 A, for the same field current, will be 15.28 Nm 15.6 Nm 15.92 Nm 16.55 Nm 15.28 Nm 15.6 Nm 15.92 Nm 16.55 Nm ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines What is/are the necessary conditions for parallel operation of alternators? Terminal voltage is same Speed of alternators should be same Frequency should be same Both 1and 2 Terminal voltage is same Speed of alternators should be same Frequency should be same Both 1and 2 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 2 pole synchronous machine is operating at 3000 rpm. Find the relation between electrical angular momentum (ωe) and mechanical angular momentum (ωm) ? ωe = 1/2*ωm ωe = 2*ωm ωe = 4*ωm ωe = ωm ωe = 1/2*ωm ωe = 2*ωm ωe = 4*ωm ωe = ωm ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a transformer zero voltage regulation is achieved at a load power factor which is unity zero leading lagging unity zero leading lagging ANSWER DOWNLOAD EXAMIANS APP