Local actions is normally prevented in a simple electric cell by
Answer Details
Local actions in a simple electric cell are caused by impurities on the surface of the zinc plate. When impurities on the surface of the zinc plate react with the acid, they form a small cell and cause the zinc to dissolve locally. To prevent local actions, the surface of the zinc plate is amalgamated (i.e. coated with mercury), which provides a uniform surface for the reaction with the acid. This prevents the formation of small cells and ensures that the current flows evenly through the cell. Therefore, the correct option is "amalgamating the surface of the zinc plate".