Odd Man Out

All except Sharpener are used for writing.

All other groups contain alternate letters, though not in order.

All except Cretinism are deficiency diseases, while Cretinism is a hormonal disease.

All except Cot are parts of bed-spread.

All except Hammer are sharp-edged and have a cutting action.

In all other pairs, second number is obtained by multiplying the first number by 8.

All the rest are parts of a house.

Carrot is the only vegetable which grows underground.

Except Potassium, all others are used as semiconductor.

ONP = NOPIHJ = HIJLKM = KLMSTR = RST (This is odd out)