UGC NET Questions (Paper – 1)

Statements A and B correctly state the meanings of universal and existential quantifiers. Statement D gives the standard rule that the negation of a universal statement becomes an existential statement with negated predicate. Statement E is also true since many mathematical theorems and definitions are framed with such quantifiers. Statement C is false because ∀x P(x) and ∃x P(x) usually have very different truth conditions. Hence A, B, D and E only are correct.

Option A:
Option A is incomplete because it omits E and does not explicitly note the role of quantified statements in formulating general laws and existence results.

Option B:
Option B is wrong because it includes C, the incorrect claim that universal and existential forms are equivalent.

Option C:
Option C is incomplete because it omits A (meaning of ∀) and also does not collect the full correct set together.

Option D:
Option D is correct since it gathers all the true statements and rejects C, which conflates different quantifier types.

Statements A, B, C and E correctly summarise the requirement that a categorical syllogism use exactly three terms and how violations occur, while D is false. Four distinct terms, whether through outright multiplication or ambiguity of a term, break the three-term rule and generate the fallacy of four terms. A two-term argument is not automatically valid; it may fail other rules. UGC NET questions do ask candidates to detect such fallacies, so E is also true. Hence A, B, C, E only constitutes the right set.

Option A:
Option A is incomplete because it omits E, failing to mention the explicit exam relevance that the question highlights. A, B, C only therefore does not fully answer the stem.

Option B:
Option B is wrong as it leaves out C, ignoring that ambiguity of the middle term can effectively produce four terms even if the same word is used. A, B, E only thus misses an important mechanism of the fallacy.

Option C:
Option C is correct because it collects all true descriptive and exam-related statements and excludes D, which incorrectly declares any two-term syllogism valid. This matches standard treatments of syllogistic structure.

Option D:
Option D is incorrect since it includes D, the false claim about two-term syllogisms, and so B, C, D, E only mixes correct and incorrect information. It therefore cannot be accepted as the correct option.

Statement A correctly defines the ad hominem fallacy as an attack on the person rather than the argument. Statement B accurately describes the straw man technique of distorting an opponent’s view. Statement C is also correct, as hasty generalisation relies on too few or biased examples to support a broad claim. Statement D is false because valid deductive arguments are structurally correct, not fallacious, and E is false since an expert authority can provide legitimate support in many contexts. Hence A, B and C only are correct, which is option C.

Option A:
Option A is incomplete since it omits C and thereby leaves out a major type of fallacy frequently tested in NET reasoning questions.

Option B:
Option B is incorrect as it includes D, which wrongly labels all valid deductions as fallacies, and it omits C, so it contains an error and misses one correct fallacy definition.

Option C:
Option C is correct because it gathers the accurate characterisations of three distinct and important fallacies, while excluding D and E, which misdescribe valid deduction and the role of authority.

Option D:
Option D is wrong since it includes E, which claims that appeal to authority is always fallacious, ignoring legitimate expert testimony, and it omits A, losing a key fallacy type.

Only statement D is wrong; all the others correctly describe valid immediate inferences. It is true that E and I propositions are simply convertible and that obversion preserves logical equivalence for the standard forms. From “All S are P” we cannot with certainty derive “Some P are S”, and UGC NET questions frequently ask which of these inferences are valid. However, from “Some S are not P” we cannot infer “No S are P”, since the particular negative does not entail the universal negative, making D the sole incorrect statement.

Option A:
Option A is correct because it isolates D as the only false statement and leaves A, B, C and E untouched as valid logical claims. It accurately reflects standard rules for conversion and obversion and the limits of what can be inferred from an O-proposition. This matches both logic texts and exam-style reasoning.

Option B:
Option B is incorrect since it treats A as wrong along with D, even though A correctly states that the converse of an A-proposition does not follow with certainty. Including A among the wrong statements therefore misrepresents a genuine logical restriction.

Option C:
Option C is wrong because it adds C to the set of allegedly wrong statements. C is in fact correct, as obversion yields a logically equivalent proposition in all four standard forms, so C and D only misclassifies an important logical law.

Option D:
Option D is also incorrect since it groups B with D, thereby wrongly branding the simple convertibility of E and I propositions as incorrect. B and D only thus fails to respect the standard conversion rules that students must know for UGC NET.

A, B and E are correct; C and D are wrong. Standard notation uses “∧” for conjunction (and) and “∨” for disjunction (or), so C and D reverse meanings. Knowing symbols helps in UGC NET equivalence problems.

Option A:
Option A is incorrect because D is also wrong; selecting only C misses another error.

Option B:
Option B is incorrect because C is also wrong; selecting only D misses another error.

Option C:
Option C is incorrect because B is true (negation symbol), so including B as wrong is incorrect.

Option D:
Option D is correct because it identifies both reversed-symbol statements (C and D) as wrong.

Statements A and B are valid argument forms (modus ponens and modus tollens). C and D are invalid forms (affirming the consequent and denying the antecedent). Statement E is also correct: validity depends on logical form, not on whether the premises are factually true. Hence the correct set of statements is A, B and E only.

Option A:
Option A is incorrect because it leaves out B (modus tollens), which is also valid, and it also ignores E, which is a true statement about validity.

Option B:
Option B is incorrect because it includes A and B but omits E, even though E correctly states that validity depends on form rather than the truth of premises.

Option C:
Option C is wrong because it includes C, and affirming the consequent is a standard fallacy; q can be true for reasons other than p.

Option D:
Option D is correct because it includes the two valid forms (A and B) and the correct general fact about validity (E), while excluding the two fallacies (C and D).

Statements A, B, D and F correctly describe central ideas about arguments, validity and exam-based reasoning, while C and E are false. Premises are indeed offered as reasons, and validity guarantees that true premises cannot lead to a false conclusion. Deductive reasoning does claim necessary support, and identifying premises and conclusion is a key skill in evaluating arguments. C is wrong because soundness requires both validity and true premises, not merely a true conclusion, and E reverses the definition of invalidity. Therefore A, B, D and F only is the correct combination.

Option A:
Option A is correct because it includes all and only the true statements: A, B, D and F. It omits C, which misdefines soundness, and E, which mischaracterises invalid arguments. By grouping just these four, it faithfully reflects standard definitions used in logical reasoning. This makes Option A the accurate representation of the correct statements.

Option B:
Option B is incorrect because it includes E as if it were true. E claims that in an invalid argument it is impossible for premises to be true and conclusion false, which is actually the hallmark of validity, not invalidity. Adding this false statement to otherwise correct ones means the combination does not match the true set of statements.

Option C:
Option C is wrong because it accepts C along with A, B, D and F. C treats any argument with a true conclusion as sound, ignoring whether the premises are true or the reasoning is valid. Since soundness depends on both validity and true premises, including C makes this option logically unacceptable.

Option D:
Option D is incorrect because it omits A and includes both C and E, thereby excluding a basic description of premises while accepting two wrong definitions. Including C and E distorts the notions of soundness and invalidity, so this combination cannot represent the correct set of statements.

Statements A, B and C present the standard relationships between necessary and sufficient conditions. A is correct because sufficiency ensures Q whenever P holds. B is true since necessity means Q cannot hold without P. C is correct as “necessary and sufficient” expresses logical equivalence. D is false; sufficiency does not generally reverse, and E is false because in “if P then Q”, P is sufficient and Q is necessary. Thus, A, B and C only are correct.

Option A:
Option A is incomplete because it omits C, and therefore does not explicitly mention the important notion of equivalence when a condition is both necessary and sufficient.

Option B:
Option B is incorrect because it includes E, which reverses the roles of P and Q in the implication, so this option accepts a false description of necessary and sufficient conditions.

Option C:
Option C is correct as it collects all three accurate conceptual definitions and excludes D and E, which misrepresent the direction and roles in implications.

Option D:
Option D is wrong since it adds D, which claims sufficiency reverses, and so includes a clear logical error alongside true statements, making the combination unacceptable.

D and E are wrong because they reverse the meanings of tautology and contingency. A tautology is true in all possible situations, not always false, and a contingent proposition is true in some situations and false in others, not true in all. Statements A and B correctly describe what counts as a statement in logic, and C accurately expresses the idea that contradictory statements cannot both be true simultaneously. Thus the pair D and E only is the correct set of wrong statements.

Option A:
Option A is incorrect because it selects D alone, but E is also wrong; contingent propositions are not true in all possible situations. By ignoring E, Option A fails to identify all the incorrect statements.

Option B:
Option B is also incorrect because it focuses only on E and ignores D, which misdefines tautology as always false. Since both D and E are wrong, singling out only one of them does not satisfy the requirement of the question.

Option C:
Option C is correct because it groups together D and E, the two statements that misrepresent the key logical categories of tautology and contingency. It leaves A, B and C untouched, acknowledging that they are true characterisations of statements and contradictions.

Option D:
Option D is wrong because it includes C, which is actually true: contradictory statements cannot both be true at the same time. By treating C as if it were wrong along with D, this option misidentifies the logical property of contradiction.

A, B and D are correct. C is false because inductive arguments can be strong or weak depending on evidence. E is false because mathematics heavily relies on deduction. Thus A, B and D only is correct.

Option A:
Option A is incomplete because it omits D (science generalisation).

Option B:
Option B is incorrect because it includes C (false) and omits D (true).

Option C:
Option C is incorrect because it includes C (false) and omits A (true).

Option D:
Option D is correct because it includes all true statements (A, B, D) and excludes the false ones (C, E).

Statements A and B restate De Morgan’s laws, showing how negation distributes over “and” and “or”, C correctly defines logical equivalence in terms of matching truth values and D is true because De Morgan’s laws explicitly connect conjunction, disjunction and negation. Statement E is false since contradictory statements cannot both be true in any possible situation; one must be false whenever the other is true. Hence, the combination A, B, C and D only is correct.

Option A:
Option A is incomplete because, although it lists three true statements, it omits D and thus does not explicitly say that De Morgan’s laws are the ones relating “and”, “or” and “not”. Without D, the named connection between these operators is not emphasised.

Option B:
Option B is also incomplete because it leaves out A and thereby fails to include the first De Morgan equivalence concerning the negation of “p and q”. That omission makes the description of the laws partial.

Option C:
Option C is correct as it bundles all four true statements, fully describing De Morgan’s laws and logical equivalence, while rejecting E, which mischaracterises contradictions. It aligns with the logical tools used in UGC NET reasoning.

Option D:
Option D is wrong because it includes E, the false statement about contradictions, and omits C, the formal definition of logical equivalence. This combination mixes error with omission.

Statements A, B and C correctly define tautology, contradiction and contingency by looking at truth across all valuations. Statement E is also true because the negation of a formula that is always true must be false on every valuation, hence a contradiction. Statement D is impossible in classical logic, since no statement can be both always true and always false at once. Therefore, the complete set of correct statements is A, B, C and E only, which matches option C.

Option A:
Option A is incomplete because it omits E and therefore fails to mention the important relationship between tautologies and contradictions via negation. It lists correct information but not the full set of true statements for this question.

Option B:
Option B is incorrect since it leaves out B and includes only A, C and E, ignoring the explicit definition of contradiction that is central to the topic. Without B the description of the three categories is not complete.

Option C:
Option C is correct as it brings together the accurate definitions of the three types of statements and the fact that the negation of a tautology is a contradiction, while excluding D, which suggests an incoherent situation in classical logic.

Option D:
Option D is wrong because it includes D, which falsely claims that a statement can be both tautology and contradiction and calls that “contingent”, and it omits A, so it both accepts a logical impossibility and loses a key correct statement.

Statements A, B and C give the standard definitions of converse, contrapositive and inverse. Statement D is also correct because in classical logic a conditional and its contrapositive share the same truth table. Statement E is false; the converse need not be logically equivalent to the original conditional, as many counterexamples show. Hence the full and only correct collection is A, B, C and D, which appears in option B.

Option A:
Option A is incomplete because it omits D and thus fails to mention that a conditional and its contrapositive are equivalent in truth value. While A, B and C are true, they do not exhaust the set of correct statements.

Option B:
Option B is correct because it includes A, B, C and D, which are all true, and it excludes E, which is false because converse is not always equivalent to the original conditional.

Option C:
Option C is wrong because it includes E, which claims that the converse is always equivalent to the original statement. Since converse can change truth conditions, including E makes this combination incorrect.

Option D:
Option D is incorrect as it leaves out A. Although B, C and D are true, omitting A loses the correct description of converse, so this option does not list all correct statements.

Statements A and B give the standard truth conditions for conjunction and inclusive disjunction. Statement D is correct because p → q is equivalent to ¬p ∨ q in classical logic. Statement E is also true since connectives allow us to build complex propositions from atomic ones. Statement C is false because ¬p is true when p is false, not when p is true. Thus A, B, D and E only form the correct set.

Option A:
Option A is incomplete as it omits E and therefore does not mention the important role of connectives in constructing compound statements, even though A, B and D are true.

Option B:
Option B is correct since it includes all true statements and excludes C, which reverses the meaning of negation. It matches the truth-table definitions that NET candidates must know.

Option C:
Option C is incorrect because it contains C, the wrong description of negation, despite including some true statements, so the overall set cannot be accepted.

Option D:
Option D is also wrong as it retains C and omits A, losing the clear definition of conjunction while endorsing an incorrect statement about negation.

Statement A is correct: arguments have premises and a conclusion. Statement B is true: indicator words help identify roles. Statement C is true: validity is about form, so with false premises the conclusion can be false even if the argument form is valid. Statement D is false because a true conclusion does not guarantee validity. Statement E is false since irrelevant information does not strengthen logical support. Therefore, A, B and C only are correct.

Option A:
Option A is incomplete because it omits C (validity vs truth nuance).

Option B:
Option B is wrong because it includes D (false) and omits C.

Option C:
Option C is correct as it includes all true statements and excludes D and E.

Option D:
Option D is incorrect because it includes E (false) and omits A.