Question 13104 of 749 · Maryland Journeyperson Electrician Exam
A single-phase transformer steps 480 volts down to 120 volts. If the primary current is 10 A, what is the secondary current (ignoring losses)?
Exactly one answer is correct.
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Correct answer to question 13104
- D: 40 A
Explanation
The turns ratio is 480 / 120 = 4 to 1, and current changes inversely with voltage: 10 x 4 = 40 A. Dividing by the ratio (2.5 A) applies the voltage relationship to current.
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