Methods and apparatus configured to evaluate a volume of interest of an earth formation intersected by a borehole. Apparatus comprise a transceiver electrode on the tool body configured to provide electrical current to the earth formation; a return electrode configured to receive the electrical current returning from the earth formation; a multi-function electrode on the resistivity imager tool; and an electrical system configured to provide current measurements at the transceiver electrode. In the first operational mode, the electrical system maintains the tool body at a first electrical potential, and maintains the multi-function electrode and the transceiver electrode at a second electrical potential; and in the second operational mode, the electrical system maintains the tool body at the first electrical potential, maintains the multi-function electrode at the first electrical potential, and maintains the transceiver electrode at the second potential.