Electrical Machines How can the synchronous speed of a 3 - Φ IM be varied? Both (A) and (B). By varying the supply frequency. By varying number of poles. By varying supply voltage. Both (A) and (B). By varying the supply frequency. By varying number of poles. By varying supply voltage. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines No load primary current in a transformer leads the applied voltage by exactly 90Â& lags behind applied voltage somewhat less than 90à lags behind applied voltage by exactly 90Â&am leads the applied voltage somewhat less than 90Ã& leads the applied voltage by exactly 90Â& lags behind applied voltage somewhat less than 90à lags behind applied voltage by exactly 90Â&am leads the applied voltage somewhat less than 90Ã& ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Two mechanically coupled alternators deliver power at 50 Hz and 60 Hz respectively. Highest speed of alternator is 500 rpm. 3600 rpm. 3000 rpm. 600 rpm. 500 rpm. 3600 rpm. 3000 rpm. 600 rpm. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines For P pole machine relation between electrical degrees and mechanical degrees is θelec = P/2*θmech θelec = 4/P*θmech θelec = 2/P*θmech θelec = θmech θelec = P/2*θmech θelec = 4/P*θmech θelec = 2/P*θmech θelec = θmech ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Hopkinson test is conducted under which of the following condition? no load full load half load any of the above no load full load half load any of the above ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Consider the following statements regarding dc machines : 1. possible resistance of shunt-field winding is 1 Ω 2. possible resistance of series-field winding is 1 Ω 3. electrographite brushes are used for 230 V, 10 A machines 4. Copper-graphite brushes are used for 230 V, 10 A machines 5. Possible armature-circuit resistance is 1 Ω From these, the correct statements are 2, 3 , 5 1, 4 1, 3, 5 2, 4 ,5 2, 3 , 5 1, 4 1, 3, 5 2, 4 ,5 ANSWER DOWNLOAD EXAMIANS APP
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