Electrical Machines A 220 V DC generator is run at full speed without any excitation. The open circuit voltage will be about 50 V. zero. 220 V. about 2 V. about 50 V. zero. 220 V. about 2 V. 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, 4 ,5 1, 3, 5 1, 4 2, 3 , 5 2, 4 ,5 1, 3, 5 1, 4 2, 3 , 5 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If s is the slip and f is the supply frequency of an induction motor, the frequency of rotor current is given by s2. sf / 2. sf. f / s. s2. sf / 2. sf. f / s. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The power factor of an induction motor operating at no load will have a value around 0.9 lag 0.2 lag unity 0.2 lead 0.9 lag 0.2 lag unity 0.2 lead ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines When the rotor speed, in a synchronous machine, becomes more than the synchronous speed during hunting, the damper bars develop DC motor torque. induction generator torque. induction motor torque. synchronous motor torque. DC motor torque. induction generator torque. induction motor torque. synchronous motor torque. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A short-shunt cumulatively-compounded dc generator builds up a voltage of 220 V at no load at rated speed. If it is operated as a differentially compounded generator, other things remaining the same, it would build up somewhat less than 220 V 6 V 220 V more than 220 V somewhat less than 220 V 6 V 220 V more than 220 V ANSWER DOWNLOAD EXAMIANS APP
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