Electrical Machines What is power factor of a 3 - φ induction motor at no load? High. Same as full load. Equal to 1. Low. High. Same as full load. Equal to 1. Low. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines For the speed control of polyphase squirrel cage induction motor, if frequency of operation is decreased with constant V, Tst increases None of these constant supply voltage V, starting torque Tst decreases either of these constant V, Tst increases None of these constant supply voltage V, starting torque Tst decreases either of these ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A self-excited shunt generator fails to build up, because 1. the field circuit is open 2. The armature circuit is open 3. the residual magnetism is absent 4. The direction of rotation is wrong From these, the correct answer is 3 only 1, 2, 3 and 4 1, 3 1, 2 and 3 3 only 1, 2, 3 and 4 1, 3 1, 2 and 3 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a DC machine the armature mmf is stationary with respect to field poles. rotating with respect to field poles as well as armature. rotating with respect to field poles. stationary with respect to armature. stationary with respect to field poles. rotating with respect to field poles as well as armature. rotating with respect to field poles. stationary with respect to armature. 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 = 10.8Ω and Xq = 8Ω Xd = 9Ω and Xq = 9.6Ω Xd = 9.6Ω and Xq = 9Ω Xd = 8Ω and Xq = 10.8Ω Xd = 10.8Ω and Xq = 8Ω Xd = 9Ω and Xq = 9.6Ω Xd = 9.6Ω and Xq = 9Ω Xd = 8Ω and Xq = 10.8Ω ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Air core transformer as compared to iron core transformer, has more copper loss. less magnetic core loss. more magnetic core loss. no magnetic core loss. more copper loss. less magnetic core loss. more magnetic core loss. no magnetic core loss. ANSWER DOWNLOAD EXAMIANS APP
EXAMIANS