Final answer:
In surgical applications and other high voltage procedures involving electrodes, most of the current flows from sharp edges due to concentrated electric fields leading to field emission. High-frequency AC is employed to cut tissue efficiently while minimizing bleeding and reducing the risk of shock.
Step-by-step explanation:
When a technician holds the high frequency electrode during application, it is referred to as direct high frequency application in some contexts. The high voltage used in this scenario is similar to surgical procedures where electricity passes from a metal scalpel through tissue. Most of the current flows from the sharp edge of the scalpel because electric fields are more concentrated at points of higher curvature, leading to a phenomenon known as field emission, where electrons are emitted from the conductor's surface due to the strong external electric field applied in the normal direction to the conductor's surface.
In surgical settings, high-frequency alternating current (AC) is often employed because it can cut or coagulate tissue with reduced bleeding and lower risk of electric shock to the patient. The use of high-frequency AC minimizes the stimulating effect on nerves and muscles, which is more pronounced at lower frequencies.