yes it is
yes. They are the same thing. Plain flour is an Australian term where all-purpose is the American.
Plain flour most likely is AP flour and I say yes at any rate.
There is no difference between plain flour and all-purpose flour. They are one and the same. All-purpose (plain) flour does not contain the salt and baking soda that self-rising flour has.
One can make other types of flour using all purpose flour, but not the reverse. The other flours have additional things added, foe example, Bread flour has wheat gluten and Self rising flour has salt and baking powders.
Self-rising Flour
In most cases plain flour is identical to all-purpose flour. All-purpose flour may be used to bake bread or pastries, whereas pastry flour has a low percentage of gluten and bread flour has a high percentage of gluten. Plain, or all-purpose flour has a medium percentage of gluten.
yes enriched flour can be substituted for all purpose flour in a cake
yes
In general, yes.
AP Flour = All Purpose Flour = Plain Flour
To substitute 1 cup of all-purpose flour with cake flour in a recipe, use 1 cup plus 2 tablespoons of cake flour for every cup of all-purpose flour called for in the recipe.
All-purpose flour is the same thing as plain flour. The terms are simply different for different parts of the world. In Australia and the United Kingdom, it is known as plain flour while in the United States and Canada it is known as All-Purpose Flour. This type of flour has a lower amount of gluten protein than bread flour, but more than baking flour so it is balanced and can be used for a wide range of purposes.