UGC NET Questions (Paper – 1)

319 ÷ 16 = 19 remainder 15 (F), and 19 ÷ 16 = 1 remainder 3. So digits are 1,3,F → 13F₁₆. Check: 1×256 + 3×16 + 15 = 319.

Option A:
Option A correctly converts 319 to 13F₁₆ and verifies by reconversion to 319.

Option B:
Option B equals 303, too small.

Option C:
Option C equals 335, too large.

Option D:
Option D equals 287, too small.

Statements A, B, C, E and F are correct, while D is false. Conversion is valid for E and I forms, obversion works by changing quality and complementing the predicate, and contraposition in its full form applies to A and O in the traditional system. Obversion is valid for all four categorical forms, and exam questions can test recognition of these operations. D is wrong because simple conversion of an A proposition is not always valid; it must usually be converted to a particular form. Therefore A, B, C, E and F only is the correct combination.

Option A:
Option A is incomplete because it stops at A, B and C and leaves out E and F, which also state correct facts about obversion and exam usage. Without acknowledging that obversion is valid for all four forms and that these operations are tested, the account is partial. Hence A, B and C only cannot be accepted.

Option B:
Option B is correct because it brings together the three operations and their main properties along with their application in UGC NET questions. It rightly excludes D, which incorrectly generalises about simple conversion of A propositions. This combination fully reflects the standard treatment of immediate inferences.

Option C:
Option C is wrong since it includes D along with B, C, E and F and omits A. Accepting D means incorrectly treating simple conversion of every A as valid, and omitting A forgets the special status of E and I in conversion. This mix of error and omission makes the option unacceptable.

Option D:
Option D is incorrect because it omits B, removing the core definition of obversion, and it also drops E. Although it mentions some correct points, without B and with the absence of E it does not capture all true statements in the list. Therefore A, C, E and F only cannot be the correct answer.