Electrical Machines A cumulatively compounded dc motor delivers rated load power at rated speed. If the series field is short-circuited, then Ia increases and ωm decreses both armature current Ia and speed ωm increase both decrese Ia remains constant but ωm increase Ia increases and ωm decreses both armature current Ia and speed ωm increase both decrese Ia remains constant but ωm increase ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The introduction of interpoles in between the main poles improves the performance of a dc machine, because the interpoles produce additional flux to augment the developed torque a counter-emf is induced in the coil undergoing commutation the inequality of air-gap flux on the top and bottom halves of the armature is removed the flux waveform is improved with reduction in harmonics the interpoles produce additional flux to augment the developed torque a counter-emf is induced in the coil undergoing commutation the inequality of air-gap flux on the top and bottom halves of the armature is removed the flux waveform is improved with reduction in harmonics ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines No load primary current in a transformer leads the applied voltage by exactly 90Â& lags behind applied voltage somewhat less than 90à lags behind applied voltage by exactly 90Â&am leads the applied voltage somewhat less than 90Ã& leads the applied voltage by exactly 90Â& lags behind applied voltage somewhat less than 90à lags behind applied voltage by exactly 90Â&am leads the applied voltage somewhat less than 90Ã& ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The field system of an alternator is usually excited 3 - Φ, 50 Hz and 400 V. 250 / 250 V DC. 110 / 220 V AC. 230 V AC. 3 - Φ, 50 Hz and 400 V. 250 / 250 V DC. 110 / 220 V AC. 230 V AC. ANSWER DOWNLOAD EXAMIANS APP
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 3.5+j5.8 ohms 3.05+j5.08 ohms 53+j85 ohms 8+j13 ohms 3.5+j5.8 ohms 3.05+j5.08 ohms 53+j85 ohms 8+j13 ohms ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The direction of rotation of a DC compound motor can be reversed by interchanging armature connections. series field connections. shunt field connections. armature or field connections. armature connections. series field connections. shunt field connections. armature or field connections. ANSWER DOWNLOAD EXAMIANS APP