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 If the frequency of input voltage of a transformer is increased keeping the magnitude of voltage unchanged, then Pe will increase but Ph will decrease both hysteresis loss(Ph) and eddy current loss(Pe) will increase Ph will increase but Pe will decrease Ph will decrease but Pe will remain same Pe will increase but Ph will decrease both hysteresis loss(Ph) and eddy current loss(Pe) will increase Ph will increase but Pe will decrease Ph will decrease but Pe will remain same ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Eg (generated emf) and Eb (back emf) both are none of above. changes. same. different. none of above. changes. same. different. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Ward Leonard control provides speed control in one direction only. in both direction. below rated speed. above rated speed. in one direction only. in both direction. below rated speed. above rated speed. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The output power of a dc motor is given by EbIa. EIa. none of these. EbIa2. EbIa. EIa. none of these. EbIa2. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The use of double squirrel cage winding on the rotor provides higher efficiency. reduced starting torque. a large starting torque. low noise. higher efficiency. reduced starting torque. a large starting torque. low noise. ANSWER DOWNLOAD EXAMIANS APP