Multiple choice Which of the following is a double working electrode ? A reference electrode A reversible hydrogen electrode A rotating disk electrode A rotating ring-disk electrode Reveal answer Fill a bubble to check yourself D Correct answer Explanation A rotating ring-disk electrode (RRDE) is double working electrode used in hydrodynamic voltammetry, very similar to a rotating disk electrode (RDE). The electrode actually rotates during experiments inducing a flux of analyte to the electrode.