Electrical Machines If peak value of phase mmf is F max , then peak value of the rotating field caused by three phase is 3Fmax. (3/2)Fmax. (1/2)Fmax. Fmax. 3Fmax. (3/2)Fmax. (1/2)Fmax. Fmax. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In DC generator, which component plays the vital role to produce the direct current? Commutator. Brush. Yoke. Armature. Commutator. Brush. Yoke. Armature. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines DC generators are usually designed to develop armature voltages not exceeding 650 V because of the limitations imposed by commutator field winding starters armature winding commutator field winding starters armature winding ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A DC shunt machine generates 250 V on open circuit at 1000 RPM. Armature resistance is 0.5 Ω, field resistance 250 Ω. When running as a motor takes 4 A at 250 V. Calculate the efficiency when running as a motor taking 40 A at 250 V. Armature reaction weakens the field by 4%. 78.5% 67.5% 72.5% 82.5% 78.5% 67.5% 72.5% 82.5% ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If starter is not used with large DC motor for starting, it will provide execessive voltage drop in line. draw a starting current many times its rated full load current. damage the armature and commutator. all of above. provide execessive voltage drop in line. draw a starting current many times its rated full load current. damage the armature and commutator. all of above. 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 two diametrically opposite quadrants and ½ ( ф - фᵢ ) in the remaining two 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 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 two adjacent 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 ANSWER DOWNLOAD EXAMIANS APP
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