A partial short in the primary of a transformer will have what effect on secondary voltage?

A partial short in the primary of a transformer can lead to an increase in the secondary voltage. This effect occurs because a partial short reduces the effective number of turns in the windings that are actively contributing to the transformation process. When this happens, the primary winding's impedance decreases, allowing more primary current to flow.

As a result, the voltage drop across the primary winding decreases, which can lead to a higher voltage being induced in the secondary winding, depending on the design and load conditions of the transformer. This phenomenon hinges on the principles of electromagnetic induction, where the primary voltage is transformed into the secondary voltage based on the turns ratio and current flowing through the windings.

While a total short would eliminate output voltage altogether due to a lack of transformer action, a partial short disrupts normal operation but can inadvertently increase the secondary voltage under specific circumstances. Therefore, the correct answer appropriately reflects the complex behavior of transformers when they encounter such irregularities.