UGC NET Questions (Paper – 1)

Saying that p is necessary for q means that q cannot occur without p. This can be formally expressed as “if not p, then not q”. The two formulations always share the same truth conditions. Therefore they stand in a relation of logical equivalence.

Option A:
Option A, contrariety, concerns pairs of propositions that cannot both be true but may both be false. It does not capture the idea that two statements always have matching truth values. Hence contrariety is not the correct answer.

Option B:
Option B correctly identifies equivalence as the relation where two statements are true and false in exactly the same circumstances. The natural-language claim about necessity and the conditional “if not p, then not q” illustrate this. Thus equivalence is the best choice.

Option C:
Option C, subalternation, relates universal and particular propositions in the traditional square of opposition. It does not describe a mutual sameness of truth conditions. Therefore subalternation is not appropriate here.

Option D:
Option D, independence, refers to propositions whose truth values do not systematically constrain each other. This is the opposite of equivalence. Consequently independence cannot be the correct answer.