When performing compounding adjustments on a generator, you should work with which field?

• A. Shunt field
• B. Series field
• C. Residual field
• D. Armature field

Answer: (B)

When adjusting how a generator’s voltage changes with load, you work with the series field winding. In a compound DC generator, the series winding is in series with the armature, so its current is essentially the load current. That means its magnetic flux rises as the load current increases. By adjusting this series field, you change how much extra flux is added on top of the shunt field flux, which in turn alters the generated EMF and the voltage regulation curve. This is exactly what compounding is meant to control: the slope of voltage rise or fall with load.

The shunt field, by contrast, provides the baseline no-load voltage and is more stable against load changes; it does not supply the current-dependent flux needed for compounding. Residual magnetism is just the remaining magnetization, not a controllable winding for adjusting the compounding effect, and the term “armature field” isn’t a standard winding used for this purpose. So the series field is the correct element to adjust for compounding.