Final answer:
Electrosurgery uses high-frequency alternating current (AC) to cut or coagulate tissue. The sharp edge of a scalpel concentrates the current due to its smaller radius of curvature, making the cutting or coagulating more efficient.
Step-by-step explanation:
Electrosurgery is the application of alternating current (AC) to coagulate or cut tissue. During electrosurgical procedures, high-voltage electricity is applied, which passes from a metal scalpel through the tissue. Most of the current tends to flow from the sharp edges of the scalpel because the electric field is more concentrated at points with a smaller radius of curvature, like the edges of a scalpel. This is reflective of the pointy-end effect where the charge density and therefore the electric field is highest at sharp points, leading to a higher current density and more efficient cutting or coagulation at those points.
For electrosurgery, a high-frequency alternating current is typically used because it is more effective at cutting or coagulating tissue while minimizing the risk of electrical shock to the patient. Lower frequency currents are more likely to interfere with the electrical signals of the body, such as those in nerves or the heart, which could be dangerous.