Which statement defines transformer voltage regulation using V_no-load and V_full-load?

Which statement defines transformer voltage regulation using V_no-load and V_full-load?

• A. VR% = [(V_full-load − V_no-load) / V_full-load] × 100
• B. VR% = [(V_no-load − V_full-load) / V_full-load] × 100
• C. VR% = [(V_no-load − V_full-load) / V_no-load] × 100
• D. VR% = [(V_no-load − V_full-load) / V_full-load] × 2000

Answer: (B)

Voltage regulation shows how much the secondary voltage falls when moving from no-load to full-load while the applied voltage stays the same. You measure the no-load secondary voltage (Vno-load) and the full-load secondary voltage (Vfull-load). The regulation is the percentage change relative to the loaded voltage, written as VR% = (Vno-load − Vfull-load) / Vfull-load × 100. Typically Vno-load is higher than Vfull-load, so the regulation is a positive percentage, representing the drop the load experiences. The other forms either use the wrong base (dividing by Vno-load) or add an arbitrary factor, which would not correctly express the load-related voltage change.

Voltage regulation shows how much the secondary voltage falls when moving from no-load to full-load while the applied voltage stays the same. You measure the no-load secondary voltage (Vno-load) and the full-load secondary voltage (Vfull-load). The regulation is the percentage change relative to the loaded voltage, written as VR% = (Vno-load − Vfull-load) / Vfull-load × 100. Typically Vno-load is higher than Vfull-load, so the regulation is a positive percentage, representing the drop the load experiences. The other forms either use the wrong base (dividing by Vno-load) or add an arbitrary factor, which would not correctly express the load-related voltage change.