common
its a nonpolar
Perhaps the word you are looking for is "normal".
The opposite of unusual is common.
Assuming you meant two forces, the tension will be 200N.
The opposite of "present" that ends in "ent" is "absent."
The opposite of typical is unusual or unique.
Antipodes are the opposite ends of the Earth, and hence of anything. Antipode and antipodal derive from it.
No country begins with N and ends with N.
The opposite ends of a magnet are called poles. All magnets have them.
Usual
Not usual; uncommon; rare; as, an unusual season; a person of unusual grace or erudition.
The opposite would be usual, ordinary, common, or average.