Electrical Machines In DC generators, the brushes remain in contact with conductors which lie in the inter polar gaps. lie under north pole. lie under south pole. there is no hard and fast rule for this. lie in the inter polar gaps. lie under north pole. lie under south pole. there is no hard and fast rule for this. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A frog leg winding is used in a DC machine to eliminate the use equalizer in lap winding. the use drum winding. the use of compensating winding. reactance voltage produced due to communication. the use equalizer in lap winding. the use drum winding. the use of compensating winding. reactance voltage produced due to communication. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines What is the speed of stator rotating magnetic field with respect to rotor rotating magnetic field? Synchronous speed Zero None of these Slip speed Synchronous speed Zero None of these Slip speed ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which of the following will vary the maximum torque? rotor reactance X None of these both 1 and 2 rotor resistance R rotor reactance X None of these both 1 and 2 rotor resistance R ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The results of a slip test for determining direct axis (Xd) and quadrature axis (Xq) reactances of a star connected salient pole alternator are given below Phase values: Vmax = 108 V ; Vmin = 96 V Imax = 12 A ; Imin = 10 A Hence the two reactances will be Xd = 9.6Ω and Xq = 9Ω Xd = 9Ω and Xq = 9.6Ω Xd = 10.8Ω and Xq = 8Ω Xd = 8Ω and Xq = 10.8Ω Xd = 9.6Ω and Xq = 9Ω Xd = 9Ω and Xq = 9.6Ω Xd = 10.8Ω and Xq = 8Ω Xd = 8Ω and Xq = 10.8Ω 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 2, 4 ,5 1, 3, 5 1, 4 2, 3 , 5 2, 4 ,5 1, 3, 5 1, 4 ANSWER DOWNLOAD EXAMIANS APP
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