Electrical Machines What is the phase difference between two windings of A.C servomotor ? 120°. 30°. 60°. 90°. 120°. 30°. 60°. 90°. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines For the speed control of polyphase squirrel cage induction motor, if frequency of operation is decreased with either of these constant V, Tst increases constant supply voltage V, starting torque Tst decreases None of these either of these constant V, Tst increases constant supply voltage V, starting torque Tst decreases None of these ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A compound dc generator is delivering full load current at a terminal voltage of 230 V. Its series-field winding gets short circuited. If its terminal voltage 1. becomes more than 230 V, it is overcompounded generator 2. becomes more than 230 V, it is differentially compounded generator 3. becomes less than 230 V, it is overcompounded generator 4. becomes less than 230 V, it is differentially compounded generator 5. becomes less than 230 V, it is level compounded generator From these, the correct answer is 1, 4, 5 1, 4 2,3 2, 3, 5 1, 4, 5 1, 4 2,3 2, 3, 5 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The residual magnetism of a self-excited dc generator is lost. To build up its emf again the field winding must be replaced the field winding connection must be reversed the armature connection must be reversed field winding must be excited by low voltage dc supply the field winding must be replaced the field winding connection must be reversed the armature connection must be reversed field winding must be excited by low voltage dc supply ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a transformer which of the following losses are zero? All of these Rotational loss Iron loss Copper loss All of these Rotational loss Iron loss Copper loss ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 240 V dc series motor takes 40 A when giving its rated output at 1500 rpm. Its resistance is 0.3 Ω. The value of resistance which must be added to obtain rated torque at 1000 rpm is 6 Ω 1.9 Ω 5.7 Ω 2.2 Ω 6 Ω 1.9 Ω 5.7 Ω 2.2 Ω ANSWER DOWNLOAD EXAMIANS APP
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