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
Electrical Machines In a synchronous motor torque or load angle δ ------------- with increase in load remains unaffected increases None of these decreases remains unaffected increases None of these decreases ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The following statements relate to compensating winding (CW) and interpole winding (IW) of a dc machine : 1. CW neutralizes the armature reaction under a pole pitch 2. IW is connected in series with armature circuit 3. IW produces mmf in the commutating zone only 4. CWmmf is directed along the brush axis 5. Mmf produced by IW is equal to armature mmf From these, the correct statements are 1, 2, 3, 4 and 5 1, 3, 4, 5 2, 3, 4, 5 2, 3, 4 1, 2, 3, 4 and 5 1, 3, 4, 5 2, 3, 4, 5 2, 3, 4 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A DC Shunt Motor having shunt field resistance of 250 Ω and armature resistance of 0.5 Ω is connected to 250 V supply and load current of 21 A. What is the back emf generated ? 230 V. 240 V. 150 V. 210 V 230 V. 240 V. 150 V. 210 V ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In case the conditions for maximum power for DC motor are established, the efficiency of the motor will be Around 100 %. Less than 50 % Around 90 % Any where between 75 % and 90 %. Around 100 %. Less than 50 % Around 90 % Any where between 75 % and 90 %. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines What is the emf generated by a 4 pole Lap connected DC Motor rotating at 1500 rpm having 1000 conductors and useful flux per pole is 0.4 mWb. 30 volts. 40 volts. 20 volts. 10 volts. 30 volts. 40 volts. 20 volts. 10 volts. ANSWER DOWNLOAD EXAMIANS APP
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