MCQ Bank
$${\text{Which of the following sets is a Borel set?}}$$
- A) $${F_\sigma }{\text{ set}}$$
- B) $${\text{The set of rational numbers}}$$
- C) $${\text{All of these}}$$
- D) $${G_\delta }{\text{ set}}$$
The Lebesgue outer measure of a Cantor set constructed from $[0,1]$, is________________.
- A) $\infty$
- B) $1$
- C) $\frac{1}{3}$
- D) $0$
Let $\varnothing \neq A,B\in \mathbf{M:}$the measurable space, such that $B\subseteq A,$ then ________.
- A) $m(B)\geq m(A)$
- B) $m(B)=m(A)$
- C) $m(B)\leq m(A)$
- D) $m(B-A)=m(A)$
Those countable sets which are Borel have _________ measure.
- A) positive
- B) infinite
- C) no
- D) zero
The Cantor set constructed from $[0,1]$ is ________________.
- A) infinitely countable
- B) finitely countable
- C) finite
- D) uncountable
What property does the Cantor set possess despite containing an uncountable infinity of points?
- A) Finite length
- B) Uncountable length
- C) Infinite length
- D) Zero length
A(an)__________of Lebesgue measure $m$ to the class of Borel sets $% \mathit{B}$ is said to be Borel measure space.
- A) restriction
- B) kernel
- C) extension
- D) bijection
If $\left\{ E_{n}\right\}$ be a sequence of measurable sets such that $% E_{1}=E_{2}=E_{3}\cdots$ then $\left\{ E_{n}\right\}$ is an example of____________sequence.
- A) increasing
- B) neither increasing nor decreasing
- C) decreasing
- D) both increasing and decreasing
What distinguishes the Cantor set from intervals of positive length?
- A) Its self-similarity
- B) Its infinite cardinality
- C) Its measure being zero
- D) Its uncountable nature
In the first iteration for constructing Cantor Set from $[0,1],$ we drop a sub-interval of length__________.
- A) $\frac{1}{2}$
- B) $\frac{1}{3}$
- C) $\frac{1}{4}$
- D) $1$
Which of the following is a property of Borel sets?
- A) Borel sets are always finite.
- B) Borel sets cannot contain uncountably many elements.
- C) Every Borel set is measurable.
- D) The complement of a Borel set is always an open set.
Let $\varnothing \neq A\in \mathbf{M:}$the measurable space, such that $t\in %TCIMACRO{\U{211d} }% %BeginExpansion \mathbb{R} %EndExpansion ,$ then________.
- A) $m(A\div t)=m(A-t)$
- B) $m(A\times t)=m(A\div t)$
- C) $m(A-t)=m(A)$
- D) $m(A\times t)=m(A+t)$
In the first iteration for constructing Cantor Set from $[0,1],$ we divide it in_____________sub-intervals.
- A) 5
- B) 3
- C) 4
- D) 2
In the 2nd Iteration for constructing Cantor Set from $[0,1],$we drop a sub-intervals of length ________________.
- A) $\frac{1}{3^{3}}$
- B) $\frac{1}{3^{2}}$
- C) $\frac{1}{3^{1}}$
- D) $\frac{1}{3^{0}}$
According to George Cantor;
- A) Cardinality$(% %TCIMACRO{\U{211d} }% %BeginExpansion \mathbb{R} %EndExpansion )\geq$Cardinality$(% %TCIMACRO{\U{211d} }% %BeginExpansion \mathbb{R} %EndExpansion ^{n})$
- B) $% %TCIMACRO{\U{211d} }% %BeginExpansion \mathbb{R} %EndExpansion =% %TCIMACRO{\U{211d} }% %BeginExpansion \mathbb{R} %EndExpansion ^{n}$
- C) Cardinality$(% %TCIMACRO{\U{211d} }% %BeginExpansion \mathbb{R} %EndExpansion )=$Cardinality$(% %TCIMACRO{\U{211d} }% %BeginExpansion \mathbb{R} %EndExpansion ^{n})$
- D) Cardinality$(% %TCIMACRO{\U{211d} }% %BeginExpansion \mathbb{R} %EndExpansion )\leq$Cardinality$(% %TCIMACRO{\U{211d} }% %BeginExpansion \mathbb{R} %EndExpansion ^{n})$
$${\text{Which operation generates }}{G_\delta }{\text{ Borel sets from open sets?}}$$
- A) Countable complementation
- B) Countable union
- C) Countable negation
- D) Countable intersection
$${\text{A singleton set }}\{ x\} {\text{ can be written as:}}$$
- A) $$\bigcap\limits_{n = 1}^\infty {\left( {x - \frac{1}{n},{\text{ }}x + \frac{1}{n}} \right)}$$
- B) $$\bigcup\limits_{n = 1}^\infty {\left( {\frac{1}{n},{\text{ }}\frac{1}{n}} \right)}$$
- C) $$\bigcap\limits_{n = 1}^\infty {\left( { - \frac{1}{n},{\text{ }}\frac{1}{n}} \right)}$$
- D) $$\bigcup\limits_{n = 1}^\infty {\left( {x - \frac{1}{n},{\text{ }}x + \frac{1}{n}} \right)}$$
For a non-empty set $E$ in a measurable set $M$________.
- A) $m(E)=m^{\ast }(E)$
- B) $m(E)>m^{\ast }(E)$
- C) $m(E)<m^{\ast }(E)$
- D) $m(E)=2m^{\ast }(E)$
$${\text{Which operation generates }}{F_\sigma }{\text{ Borel sets from closed sets?}}$$
- A) Countable negation
- B) Countable union
- C) Countable intersection
- D) Countable complementation
If $\left\{ E_{n}\right\}$ be a decreasing sequence of measurable sets then____________.
- A) $E_{1}\supseteq E_{2}\supseteq E_{3}\supseteq \cdots$
- B) $E_{1}-E_{1}\subseteq E_{1}-E_{2}\subseteq E_{1}-E_{3}\subseteq \cdots E_{1}-E_{n}\subseteq \cdots$
- C) $E_{1}\subseteq E_{2}\subseteq E_{3}\subseteq \cdots$
- D) $E_{1}\neq E_{2}\neq E_{3}$