UPSC Civil Services Model Paper 4

Sheet Mica is used for atomic force microscopy (a very high resolution of microscoping).
So, statement 4 is NOT correct.
Manganese dioxide has been used since antiquity to oxidatively neutralize the greenish tinge in the glass caused by trace amounts of iron contamination.
MnO2 is also used in the manufacture of oxygen and chlorine, and in drying black paints.
Manganese is mainly used in the manufacturing of steel and ferromanganese alloy.
Nearly 10 kg of manganese is required to manufacture one tonne of steel.
It is also used in preparing insecticides and bleaching powder.