Electrical Machines The leakage reactance of a 3-phase alternator is determined by performing short circuit and slip tests. open circuit and short circuit tests. zero power factor and slip tests. open circuit and zero power factor tests. short circuit and slip tests. open circuit and short circuit tests. zero power factor and slip tests. open circuit and zero power factor tests. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A separately-excited DC generator, running at rated speed, has 6 volts across its armature terminals with no field current. When field winding is excited with one ampere, the voltage builds up to 250 V at no load. In case field current is reduced to zero, with the speed remaining unaltered, the armature terminal voltage would be more than 6 V less than 6 V 6 V zero more than 6 V less than 6 V 6 V zero ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A slip ring Induction motor runs at 290 rpm at full load, when connected to 50 Hz supply. Determine the number of poles and slip. P = 50, s = 4.43 %. P = 60, s = 0.96 %. P = 40, s = 5.79 %. P = 20, s = 3.33 %. P = 50, s = 4.43 %. P = 60, s = 0.96 %. P = 40, s = 5.79 %. P = 20, s = 3.33 %. 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 1, 3, 5 2, 4 ,5 2, 3 , 5 1, 4 1, 3, 5 2, 4 ,5 2, 3 , 5 1, 4 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The DC generator runs at a speed of 1000 rpm and flux per pole is 0.2 Wb, number of poles are 2 the winding is wave wound and having 480 conductors. The critical speed is 1200 rpm. Then the generated emf ( Eg ) 0 Volt. 1600 Volt. 2000 Volt. 1500 Volt. 0 Volt. 1600 Volt. 2000 Volt. 1500 Volt. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a DC generator, if P be the number of poles and N be the rpm of the rotor, then frequency of magnetic reversals will be PN/3000. PN/2. PN/60. PN/120. PN/3000. PN/2. PN/60. PN/120. ANSWER DOWNLOAD EXAMIANS APP
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