Final answer:
Most current in electrosurgery flows from the scalpel's sharp edge due to concentrated electric fields. High-frequency AC is used for precise cuts and to reduce muscle stimulation.
Step-by-step explanation:
In surgeries that involve high-voltage electricity, most of the current flows from the sharp edge of the scalpel due to the concentration of electric fields at the tips or edges of conductors. The sharp edge creates a high-intensity field which leads to a focused cutting action, allowing for cleaner and more precise incisions. High-frequency AC is often used in this method, known as electrosurgery, because it causes less muscle stimulation than low-frequency AC and can minimize the risk of unwanted nerve and muscle reactions during the procedure.