Question 249Electricity/Electronics - Assistant Engineer70% to pass
In figure "1" of the diagram shown in the illustration, the three phase step-down power transformer has a turns ratio of four to one. If a three-phase 440 volt supply is connected to terminals "A1-B1-C1", what voltage should develop across terminals "A2-B2-C2"? Illustration EL-0084
AI Explanation
The correct answer is B) 110 volts.
The turns ratio of the three-phase step-down transformer is 4:1, meaning that for every 4 turns on the primary side, there is 1 turn on the secondary side. Since the primary voltage is 440 volts, the secondary voltage can be calculated by dividing 440 volts by the turns ratio of 4, which results in 110 volts.
The other options are incorrect because:
A) 64 volts is too low for a 4:1 step-down transformer.
C) 190 volts is too high for a 4:1 step-down transformer.
D) 762 volts is the primary voltage multiplied by the turns ratio, which is not the secondary voltage.
Related Questions
#247 You are in the planning stages of setting the longtime overcurrent trip of a ship's service generator circuit breaker. According to 46 CFR, Subchapter J (Electrical Engineering), what statement is true regarding the criteria for the longtime overcurrent trip setpoint, assuming the generator is capable of being paralleled? #248 The turns ratio of the tapped step-down transformer shown in figure "C" of the illustration is four to one and all taps are equally spaced. If 440 volts were applied between 'H1' and 'H4', what would appear across 'X1' and 'X4'? Illustration EL-0082 #250 In figure "2" of the diagram shown in the illustration, the three phase step-down power transformer has a turns ratio of four to one. If a three-phase 480 volt supply is connected to terminals "A1-B1-C1", what voltage should develop across terminals "A2-B2-C2"? Illustration EL-0084 #251 The turns ratio of the tapped step-down transformer shown in figure "C" of the illustration is four to one and all taps are evenly spaced. If 120 volts were applied to terminals 'H1' and 'H3', what would appear at 'X1' and 'X2'? Illustration EL-0082 #252 In figure "4" of the diagram in the illustration, the three phase step-down power transformer has a turns ratio of five to one. If a three-phase 4160 volt supply is connected to terminals "A1-B1-B2", what voltage should develop across terminals "A2- B2-C2"? Illustration EL-0084