Final answer:
In surgical procedures using high-voltage electric scalpels, the current primarily flows from the sharp edge due to the nature of electric fields, and low-frequency AC is used to reduce tissue damage.
Step-by-step explanation:
In surgical procedures, some techniques involve the use of high-voltage electricity to pass a current through a metal scalpel, facilitating the cutting of tissue. One reason most of the current flows from the sharp edge of the scalpel is due to the nature of electric fields at the surface of conductors. Electric fields are more intense at sharp edges, where the curvature is greater, encouraging a higher concentration of current to flow from these points. Regarding the frequency of the alternating current (AC) used in these procedures, low-frequency AC is commonly employed because it is less likely to cause unwanted stimulation of muscles and nerves, and it minimizes the risk of tissue damage that high-frequency currents might cause.