Electrical Machines The fall in speed of the DC generator due to increase in load can be corrected by increasing the excitation. reducing the load voltage. cooling the armature. increasing the input to the prime mover. increasing the excitation. reducing the load voltage. cooling the armature. increasing the input to the prime mover. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Cogging and crawling are phenomena associated with any of the above. cage induction machines and they are essentially the same. the former at a fraction of its rate speed and the latter during starting. the former during starting and the latter at a fraction of its rated speed. any of the above. cage induction machines and they are essentially the same. the former at a fraction of its rate speed and the latter during starting. the former during starting and the latter at a fraction of its rated speed. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a transformer the magnetic coupling between the primary and secondary winding can be increased by using the magnetic core of low reluctance. increasing the number of turns. using soft material for winding. using transformer oil of better quality. using the magnetic core of low reluctance. increasing the number of turns. using soft material for winding. using transformer oil of better quality. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A transformer core is made up of a silicon steel laminations which has maximum flux density 1 Tesla. If it was cold rolled grain oriented its flux density increases to 1.6 Tesla. What is the saving in core size or area due to cold rolled grain oriented process? 38% 68% 40% 60% 38% 68% 40% 60% ANSWER DOWNLOAD EXAMIANS APP
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 all the four quadrants ½ ( ф + фᵢ ) in two adjacent quadrants and ½ ( ф - фᵢ ) in the remaining two quadrants ½ ( ф - фᵢ ) in all the four 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 two adjacent quadrants and ½ ( ф - фᵢ ) in the remaining two quadrants ½ ( ф - фᵢ ) in all the four quadrants ½ ( ф + фᵢ ) in two diametrically opposite quadrants and ½ ( ф - фᵢ ) in the remaining two Quadrants ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If the full load speed of 3-phase, 50Hz induction motor is 950 rpm, what is its half load speed nearly equals to? 975 rpm 1000 rpm 940 rpm 950 rpm 975 rpm 1000 rpm 940 rpm 950 rpm ANSWER DOWNLOAD EXAMIANS APP
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