What is the primary purpose of supplementary bonding?

The primary purpose of supplementary bonding is to reduce the voltage between exposed conductive parts and extraneous conductive parts during a fault condition. This is accomplished by connecting these conductive components together to ensure that, in the event of a fault, the potential difference that could cause electric shock is minimized. By bonding these parts, any rise in voltage due to a fault can be equalized, thus reducing the risk of electric shock to individuals and protecting sensitive equipment. This is particularly important in environments where conductive parts may be exposed or accessible, such as in bathrooms, kitchens, or around swimming pools, where the risk of electric shock is heightened.

The other options, while related to electrical systems, do not accurately capture the primary function of supplementary bonding. Increasing current flow pertains more to the design of electrical circuits, enhancing insulation deals with preventing any unwanted current flow, and ensuring better connectivity relates to the overall integrity of electrical connections rather than the specific safety function that supplementary bonding provides in fault conditions.