Electrical Machines A 100 KVA transformer is operating at 60 Hz, 240 V supply. The same transformer is operating at 50 Hz, 200 V supply. The new rating is 83.33 KVA 100 KVA 50 KVA 123.3 KVA 83.33 KVA 100 KVA 50 KVA 123.3 KVA ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines High inrush of current during a starting of DC motor can efficiently be restricted to a safer value by increasing the _________________ resistance. shunt field both A and B armature circuit none of above shunt field both A and B armature circuit none of above ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Consider the following statements regarding the speed control of dc motors : 1. ward-leonard method is suitable forconstant-torque drives 2. Ward-leonard method is suitable for constant-power drives 3. field-control method facilitates speed control below base speed 4. Armature-resistance control method is more efficient than ward-leanard method 5. Field-control method is suitable for constant-torque drives 6. Armature-resistance control method is suitable for constant-torque drives From these, the correct answer is 1, 2, 5 1, 2, 6 1, 4, 6 1, 3, 5 1, 2, 5 1, 2, 6 1, 4, 6 1, 3, 5 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines For a DC Shunt Motor having armature resistance of 0.5 Ω and 2A armature current at no-load, when the armature current is changed to 20A at loaded condition the speed is 1000 r.p.m. What is the speed at no-load? 4575.4 r.p.m. 963.8 r.p.m. 1037.5 r.p.m. 1130 r.p.m. 4575.4 r.p.m. 963.8 r.p.m. 1037.5 r.p.m. 1130 r.p.m. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Essential conditions for two DC generators are connecting for parallel operation is/are both A and B. polarities should be same. terminal voltage should be same. rating of generators should be same. both A and B. polarities should be same. terminal voltage should be same. rating of generators should be same. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In case of a dc motor the ratio Eb / E is indicative of ratio of starting to running torque. ratio of starting to running current. efficiency. ratio of input to output voltage. ratio of starting to running torque. ratio of starting to running current. efficiency. ratio of input to output voltage. ANSWER DOWNLOAD EXAMIANS APP
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