Electrical Machines The magnetic field which initially induces emf in the armature in a self excited DC generator is because of None of these residual magnetism. armature reaction. permanent magnets. None of these residual magnetism. armature reaction. permanent magnets. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If Kh is hysteresis constant, f is supply frequency, Bm maximum flux density in core of transformer, the expression of hysteresis loss in transformer, is given by Khf2Bm1.6. KhfBm3. KhfBm. KhfBm1.6. Khf2Bm1.6. KhfBm3. KhfBm. KhfBm1.6. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 3 - Φ, 400 / 200 V, Y - Y connected wound rotor induction motor has 0.06 Ω rotor resistance and 0.3 Ω standstill reactance per phase. To make the starting torque equal to maximum torque of the motor the additional resistance required 0.78 Ω. 0.45 Ω. 0.24 Ω. 0.66 Ω. 0.78 Ω. 0.45 Ω. 0.24 Ω. 0.66 Ω. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The polarity of a DC generator can be reversed by reversing the field current. any of above. reversing field electric current as well as direction of rotation. increasing field current. reversing the field current. any of above. reversing field electric current as well as direction of rotation. increasing field current. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Flashing of DC generator means increasing flux density by providing extra ampere-turns in field. creation of residual magnetism by a DC source. None of these neutralization of residual magnetism. increasing flux density by providing extra ampere-turns in field. creation of residual magnetism by a DC source. None of these neutralization of residual magnetism. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In case of induction motors the ratio of length to pole pitch for minimum cost, is taken as 3 to 5. 1.5 to 2. 1.0. 2 to 3. 3 to 5. 1.5 to 2. 1.0. 2 to 3. ANSWER DOWNLOAD EXAMIANS APP
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