Electrical Machines Which of the following machine is invariably provided with forced ventilation? 50 MW generator in a power plant. Fractional horse power high speed motor. Hermetically sealed motor of refrigerator. Fractional horse power slow speed motor. 50 MW generator in a power plant. Fractional horse power high speed motor. Hermetically sealed motor of refrigerator. Fractional horse power slow speed motor. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines which of the following losses are negligible in blocked rotor test? both A and B iron loss mechanical loss copper loss both A and B iron loss mechanical loss copper loss ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a DC Shunt Motor the speed can be increased by Increasing the field current. Decreasing the field current. Increasing the field current. Increasing the armature current. Increasing the field current. Decreasing the field current. Increasing the field current. Increasing the armature current. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If an additional resistance is connected in series with a DC series motor operating at rated speed, the speed of the motor will Remain unaltered. Reduce. Oscillate around the normal speed. Increase. Remain unaltered. Reduce. Oscillate around the normal speed. Increase. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines How can the synchronous speed of a 3 - Φ IM be varied? By varying the supply frequency. By varying number of poles. Both (A) and (B). By varying supply voltage. By varying the supply frequency. By varying number of poles. Both (A) and (B). By varying supply voltage. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 240 V, dc shunt motor draws 15 A while supplying the rated load at a speed of 80 rad/s. The armature resistance is 0.5 W and the field winding resistance is 80 W. The external resistance to be added in the armature circuit to limit the armature current to 125% of its rated value is 15.9 Ω 15.1 Ω 31.9 Ω 31.1 Ω 15.9 Ω 15.1 Ω 31.9 Ω 31.1 Ω ANSWER DOWNLOAD EXAMIANS APP
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