Electrical Machines Hopkinss test in DC motor is conducted at ? Full load. No load. None of these. Low load. Full load. No load. None of these. Low load. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which of the following represents the rotating losses of machine? Friction and windage losses Hysteresis losses All of the them Eddy current losses Friction and windage losses Hysteresis losses All of the them Eddy current losses ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Saving of copper in auto transformer is increased as compared to two winding transformer, when transformation ratio K approaches to unity. zero. infinity. two. unity. zero. infinity. two. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A part an alternator winding consist of eight coils in series, each having an emf of 20 V rms induced in it. Coils are placed in successive slots and between each slot and the next, there is an electrical phase displacement of 30°. Find the emf of eight coils in series 66.91 V. 56.91 V. 86.91 V. 76.91 V. 66.91 V. 56.91 V. 86.91 V. 76.91 V. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The residual magnetism of a self-excited dc generator is lost. To build up its emf again the armature connection must be reversed the field winding connection must be reversed the field winding must be replaced field winding must be excited by low voltage dc supply the armature connection must be reversed the field winding connection must be reversed the field winding must be replaced field winding must be excited by low voltage dc supply ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Consider the following statements regarding the speed control of dc motors : 1. ward-leonard method is suitable forconstant-torque drives 2. Ward-leonard method is suitable for constant-power drives 3. field-control method facilitates speed control below base speed 4. Armature-resistance control method is more efficient than ward-leanard method 5. Field-control method is suitable for constant-torque drives 6. Armature-resistance control method is suitable for constant-torque drives From these, the correct answer is 1, 4, 6 1, 2, 6 1, 2, 5 1, 3, 5 1, 4, 6 1, 2, 6 1, 2, 5 1, 3, 5 ANSWER DOWNLOAD EXAMIANS APP
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