Define doubling effect and de offset current.

Doubling Effect : Doubling effect occurs in rectifier circuits when the output ripple frequency becomes twice the supply frequency. For example, in a full-wave rectifier fed from a 50 Hz AC supply, the ripple frequency after rectification is 100 Hz. This results in smoother DC output compared to half-wave rectification.

DC Offset Current : DC offset current is the unwanted direct current component present in an otherwise alternating current waveform. It shifts the waveform above or below the zero line, which can cause issues like core saturation in transformers or increased losses in AC machines.