Electrical Machines A bipolar dc machine with interpoles has a main-pole flux of ф per pole and an interpole flux of Фᵢ per pole. The yoke of the machine is devide into four quadrants by the main-pole axis and The commutation axis. The flux-distribution in the quadrants will be ½ ( ф + фᵢ ) in two diametrically opposite quadrants and ½ ( ф - фᵢ ) in the remaining two Quadrants ½ ( ф - фᵢ ) in all the four quadrants ½ ( ф + фᵢ ) in all the four quadrants ½ ( ф + фᵢ ) in two adjacent quadrants and ½ ( ф - фᵢ ) in the remaining two quadrants ½ ( ф + фᵢ ) in two diametrically opposite quadrants and ½ ( ф - фᵢ ) in the remaining two Quadrants ½ ( ф - фᵢ ) in all the four quadrants ½ ( ф + фᵢ ) in all the four quadrants ½ ( ф + фᵢ ) in two adjacent quadrants and ½ ( ф - фᵢ ) in the remaining two quadrants ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The residual magnetism of a self-excited dc generator is lost. To build up its emf again the field winding must be replaced the field winding connection must be reversed the armature connection must be reversed field winding must be excited by low voltage dc supply the field winding must be replaced the field winding connection must be reversed the armature connection must be reversed field winding must be excited by low voltage dc supply ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The armature mmf in a dc machine is 1. stationary with respect to field poles 2. stationary with respect to armature 3. rotating with respect to field poles 4. rotating with respect to armature From these, the correct answer is 1, 4 2, 4 1, 3 2, 3 1, 4 2, 4 1, 3 2, 3 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The type of DC generator used for arc welding purpose is a cumulatively compounded generator series generator shunt generator differentially compounded generator cumulatively compounded generator series generator shunt generator differentially compounded generator ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The magnetic circuit of a dc shunt generator with negligible armature resistance and brush contact voltage drop remains unsaturated when it delivers full-load current at rated terminal voltage. The brushes are kept in the interpolar axis and speed is maintained constant. When the load is switched off, the terminal voltage would decrease increase become zero remain the same decrease increase become zero remain the same ANSWER DOWNLOAD EXAMIANS APP
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