Electrical Machines To control the speed of an induction motor, the supply frequency is reduced by 10%. For the same magnetizing current to remain constant, the supply voltage must be reduced by 20% reduced by 10% increased by 10% increased by 20% reduced by 20% reduced by 10% increased by 10% increased by 20% ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A self-excited shunt generator fails to build up, because 1. the field circuit is open 2. The armature circuit is open 3. the residual magnetism is absent 4. The direction of rotation is wrong From these, the correct answer is 1, 2 and 3 1, 2, 3 and 4 1, 3 3 only 1, 2 and 3 1, 2, 3 and 4 1, 3 3 only ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines R1 is the resistance of the primary winding of the transformer. The turn ratio in terms of primary to secondary is K. Then the equivalent resistance of the primary referred to secondary is K²R1 R1 /K² R1 /K K×R1 K²R1 R1 /K² R1 /K K×R1 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 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 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 Which of the following machine is invariably provided with forced ventilation? Hermetically sealed motor of refrigerator. 50 MW generator in a power plant. Fractional horse power high speed motor. Fractional horse power slow speed motor. Hermetically sealed motor of refrigerator. 50 MW generator in a power plant. Fractional horse power high speed motor. Fractional horse power slow speed motor. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Lap winding is prefered for which type of machines? low current and low voltage high current and high voltage high current and low voltage low current and high voltage low current and low voltage high current and high voltage high current and low voltage low current and high voltage ANSWER DOWNLOAD EXAMIANS APP
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