Maginot Line exists between which countries?

Famous ‘Ruhr coalfield’ is situated in which of the following countries?

Which one of the following is not correctly matched?

In which of the following districts in India the largest 'Mica Belt' is found?

Which one of the following Indian States account for the maximum deposits of Bauxite and Chromite?

Which one among the following pairs of mine and mineral is NOT correctly matched?