Electrical Machines A 5 KVA transformer has a turns ratio of N1/N2 = 10. The impedance of primary winding is 3+j5 ohms while that of secondary winding is 0.5+j0.8 ohms. The impedance of transformer when referred to primary will be 3.05+j5.08 ohms 3.5+j5.8 ohms 8+j13 ohms 53+j85 ohms 3.05+j5.08 ohms 3.5+j5.8 ohms 8+j13 ohms 53+j85 ohms ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Two transformers with identical rating, are designed with flux densities of 1.2 and 1.4 Wb / m2 respectively. The weight of first transformer per kVA is more than that of second transformer. equal to that of second transformer. none of these. less than that of second transformer. more than that of second transformer. equal to that of second transformer. none of these. less than that of second transformer. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a DC shunt generator working on load, the brushes are moved forward in the direction of rotation, as a result of this, commutation will worsen and terminal voltage will fall improve but terminal voltage will fall. worsen and terminal voltage will rise. improve and terminal voltage will rise . worsen and terminal voltage will fall improve but terminal voltage will fall. worsen and terminal voltage will rise. improve and terminal voltage will rise . ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In the 3-phase induction motor, the resultant flux is of a constant nature and is equal to φm, where φm is the maximum flux due to any phase 1/2 times maximum value of flux due to any phase 3 times maximum value of flux due to any phase 3/2 times maximum value of flux due to any phase equal to φm, where φm is the maximum flux due to any phase 1/2 times maximum value of flux due to any phase 3 times maximum value of flux due to any phase 3/2 times maximum value of flux due to any phase 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, 2, 6 1, 4, 6 1, 3, 5 1, 2, 5 1, 2, 6 1, 4, 6 1, 3, 5 1, 2, 5 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In DC generators, electric current to the external circuit from armature is given through slip rings. none of above. commutator. solid connection. slip rings. none of above. commutator. solid connection. ANSWER DOWNLOAD EXAMIANS APP