Q21.Helne-Borel property ensures that:
Correct answer: An open cover of a compact set has a finite sub-cover
Q22.In a complete metric space:
Correct answer: Every Cauchy sequence is convergent
Q23.For metric space X with metric d, the map is: X X is a contraction of X, if, for x, y ∈ X:
Correct answer: d((x), (y)) cd(x, y) with 0 < c < 1
Q24.In a topological space (X, T), Where X = {a, b, c} and T = {φ, {a},{b, c}, X}. Which of the following is true?
Correct answer: Sets in T are both open and closed
Q25.Every regular Lindelof space is
Correct answer: Normal
Q26.A subspace of a normal space is
Correct answer: Need not normal
Q27.Let X = {a, b, c} and T = {φ, {a},{a, b}, X} be a topology on X. Then (X, T) is
Correct answer: Compact only
Q28.Which one of the following is NOT a topology on X = {a, b, c}?
Correct answer: {,{a},{b},{c},{a,b},X} φ
Q29.Let X = {a, b, c} and T = {φ, {a}, {a, b},{a, c}, X} be a topology on X. If A = {a, c}, then derived set of A is
Correct answer: {b, c}
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Q30.A subset Y of a topological space (X, τ τ τ) is no where dense if -
Correct answer: Y has empty interior
EnglishUP Higher Asst. Prof. 2021
Q31.Any infinite subset A of a discrete topological space X is,
Correct answer: not compact
EnglishUP Higher Asst. Prof. 2021
Q32.Metric d is known as pseudo metric if -
Correct answer: x = y ⇒ d(x, y) = 0
Q33.Which of the following is a topology on X = {a, b, c, d}?
Correct answer: { },{a},X φ
EnglishUPPSC Polytechnic Lecturer 2021 (I) UP Higher Asst. Prof. 2021
Q34.Which of the following in not correct?
Correct answer: 2 3 T – space T – space ⇒
EnglishUPPSC Polytechnic Lecturer 2021 (I)
Q35.A subset 'A' of a topological space 'X' is said to be not dense if-
Correct answer: A = φ
EnglishUPPSC Polytechnic Lecturer 2021 (I)
Q36.Consider { } { } { } { } φ 1 J =,X, a, b, a,b and { } { } { } φ 2 J =,X, a,b, b,c. Which of the above is/are a topology on { } X = a,b,c?
Correct answer: Only J1
EnglishUPPSC Polytechnic Lecturer 2021 (I)
Q37.The number of non-trivial topologies on a set { } X = a,b,c is–
Correct answer: 28
EnglishUPPSC Polytechnic Lecturer 2021 (I)
Q38.Let X = {a,b,c} and let { } φ J =,{a},{b,c},X, then
Correct answer: (X,J) is normal
EnglishUPPSC Polytechnic Lecturer 2021 (I)
Q39.In which of the following cases, there is no continuous function 'f' from the set 'S' onto set 'T'?
Correct answer: S=[a,b],T=R
EnglishUPPSC Polytechnic Lecturer 2021 (I)
Q40.Let (X,J) be a topological space, where X={1,2,3,4,5} and J= { } φ,X,{2},{3,4},{2,3,4},{1,2,3,4}. If A= {1,3,4}, then interior of A is-
Correct answer: {3,4}