At least here in the U.S. cast iron isn't recommended for ceramic cook tops (your "hob") since to efficiently conduct the heat from the range top to the pan the bottom of the pan must be perfectly flat. We use cast iron skillets of various sizes almost exclusively, but friends have special pans for their ceramic cook tops...
My range cooker has got a griddle plate on it with a ceramic area underneath. The issue with cast iron and ceramic hob is that the pan is heavy and thus people may be inclined to slide it over the hob instead of lifting vertically. Any slight imperfection in the cast thus risks damaging the hob.