Red Seal Electrician Practice
TransformersQuestion 1430 of 1506

A single-phase transformer steps 600 V down to 208 V. The secondary load current is 20 A. What is the primary current?

  1. 12.0 A
  2. 57.7 A
  3. 20.0 A
  4. 6.93 A
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Correct answer: 6.93 A

Ip = Is × (Vs ÷ Vp) = 20 × (208 ÷ 600) = 6.93 A. The higher voltage side carries the lower current.

Source: Computed, 1.1: What is Alternating Current (AC)?

Practice transformers

Questions last reviewed: 18 October 2026