During recovery, a nerve fibre becomes

During an action potential (the electrical signal that travels along a nerve fiber), there are different phases including depolarization and repolarization:

• Depolarisation: At the beginning of an action potential, the nerve membrane becomes less negative (more positive) inside compared to its resting state. This is caused by the influx of positively charged ions, primarily sodium ions, through ion channels in the membrane.
• Repolarisation: After depolarization, the membrane potential needs to return to its resting state. Repolarisation involves the restoration of the negative charge inside the cell. This is achieved by the efflux of positively charged ions, mainly potassium ions, out of the cell through ion channels.

So, during repolarisation, the nerve fiber becomes negatively charged inside (as positive ions exit the cell) and positively charged ions are more concentrated outside the cell.