MCQ Bank
If the integral operator $I:c\left[ 0,1\right] \rightarrow %TCIMACRO{\U{211d} }% %BeginExpansion \mathbb{R} %EndExpansion ,$ on the space of all contnuous functions on $\left[ 0,1\right]$ defined by $f(x)=\int_{0}^{1}x\left( t\right) dt$, is a linear functional, then $% \left\vert f\left( x\right) \right\vert \leq$
- A) $1$
- B) $\underset{0\leq t\leq 1}{\max }\left\vert x\left( t\right) \right\vert$
- C) $\left\Vert x\right\Vert$
- D) $\left\vert x\right\vert$
Two operators ${T_1}\,\,and\,\,{T_2}$ are equal if
- A) $D({T_1}) = D({T_2})$ and $\forall \,\,x \in D({T_1}) = D({T_2})\,\, \Rightarrow \,\,{T_1}(x) = {T_2}(x)$
- B) $D({T_1}) = D({T_2})$
- C) $\forall \,\,x \in D({T_1}) = D({T_2})\,\, \Rightarrow \,\,{T_1}(x) = {T_2}(x)$
- D) $D({T_1}) = D({T_2})$ and $\forall \,\,x \in R({T_1}) = R({T_2})\,\, \Rightarrow \,\,{T_1}(x) = {T_2}(x)$
For a fixed $t\in \left[ 0,1\right] ,$ defining the linear functional on the class of all continous functions on $\left[ 0,1\right] ,$ $f:c\left[ 0,1% \right] \rightarrow %TCIMACRO{\U{211d} }% %BeginExpansion \mathbb{R} %EndExpansion$ as $f\left( x\right) =x\left( t\right) ,~\forall x\in c\left[ 0,1\right] ,$ then $\left\Vert f\right\Vert =$
- A) $\underset{t\in \left[ 0,1\right] }{\max }x\left( t\right)$
- B) $\underset{t\in \left[ 0,1\right] }{\min }x\left( t\right)$
- C) $1$
- D) $0$
A linear functional f with domain D in a normed space is continuous if and only if f is
- A) Integrable.
- B) Bounded.
- C) Differentiable.
- D) Real valued.
If T is a continuous linear operator from a normed space X to normed space Y, then T is _________.
- A) unbounded as well irrespective of dimension of X and Y
- B) unbounded as well provided that X and Y are infinite dimensional
- C) bounded as well provided that X and Y are finite dimensional
- D) bounded as well irrespective of dimension of X and Y
Let $X$ be a normed space, $f :$$X \rightarrow \mathbb{R}$ be the linear functional and for any $\alpha \in \mathbb{R}$ , then $\alpha f :X \rightarrow \mathbb{R}$ defined by $\left (\alpha f\right )(x) =\alpha f(x) \forall x\text{} \in X\text{, is _______}$ a linear functional.
- A) not necessarily
- B) essentially
- C) never
- D) bounded
............ is a mapping from a space 'X' to its Second Dual.
- A) Isomorphism
- B) Surjection
- C) Canonical
- D) Bijection
For a bounded linear operator $T$ , the null space ${\rm N}(T)$ is
- A) closed.
- B) unbounded.
- C) bounded.
- D) open.
Functionals defined on C[a,b] are
- A) Integrable.
- B) Canonical mappings.
- C) Linear and bounded.
- D) Unbounded.
Canonical mapping is defined as
- A) $$C:X \to X^{**}$$
- B) $$C:X \to R$$
- C) $$C:X \to X$$
- D) $$C:X \to R(Y)$$
Matrix operator is
- A) Linear and bounded.
- B) Non linear.
- C) Linear.
- D) Nonlinear and unbounded.
If a normed space $X$ is finite dimensional , then every linear operator on $X$ is
- A) Differentiable.
- B) Integrable.
- C) Continuous.
- D) Bounded.
Let $T:% %TCIMACRO{\U{211d} }% %BeginExpansion \mathbb{R} %EndExpansion \rightarrow %TCIMACRO{\U{211d} }% %BeginExpansion \mathbb{R} %EndExpansion$ be defined by $T\left( x\right) =x^{2}$, then the restriction $T_{|A}$ is one-one on $A=$
- A) $\left( -1,\infty \right)$
- B) $\left( -\infty ,1\right)$
- C) $\left( -\infty ,0\right)$
- D) $\left( -\infty ,\infty \right)$
If $T$ is a linear opertor on a finite dimensional normed space $X$ having basis $\left\{ e_{1},e_{2},\ldots ,e_{n}\right\} ,$then for any $x\in X$ $\exists ~\left\{ \alpha _{i}\right\} _{i=1}^{n},$ $x=\sum_{i=1}^{n}% \alpha _{i}e_{i},$ then $\left\Vert T\left( \sum_{i=1}^{n}\alpha _{i}e_{i}\right) \right\Vert$
- A) $\leq \sum_{i=1}^{n}\left\vert \alpha _{i}\right\vert \left\Vert Te_{i}\right\Vert$
- B) $\leq \sum_{i=1}^{n}\left\vert T\alpha _{i}\right\vert \left\Vert e_{i}\right\Vert$
- C) $\leq T\left\Vert \sum_{i=1}^{n}\alpha _{i}e_{i}\right\Vert$
- D) $\leq \sum_{i=1}^{n}\left\vert T\alpha _{i}\right\vert \left\Vert Te_{i}\right\Vert$
If $T$ is a linear opertor on a finite dimensional normed space $% X$ having basis $\left\{ e_{1},e_{2},\ldots ,e_{n}\right\} ,$then for any $% x\in X$ $\exists ~\left\{ \alpha _{i}\right\} _{i=1}^{n}\subset F,$ such that
- A) $x=\alpha _{i}\sum_{i=1}^{n}e_{i},$ for any fixed $\alpha _{i}$
- B) $x=\sqrt{\sum_{i=1}^{n}\alpha _{i}e_{i}}$
- C) $x=e_{i}\sum_{i=1}^{n}\alpha _{i},$ for any fixed $e_{i}$
- D) $x=\sum_{i=1}^{n}\alpha _{i}e_{i}$
If $Tx_{n}=0$ for a sequence $\left\{ x_{n}\right\}$ in a null space $% N\left( T\right) ~$of a bounded linear operator $T$ on a normed space $X,$ then$~x_{n}\rightarrow x\Longrightarrow x=$
- A) unit vector
- B) zero vector
- C) is neither unit vector nor zero vector
- D) is either unit vector or zero vector
Let $T:\left[ 0,\infty\right) \rightarrow %TCIMACRO{\U{211d} }% %BeginExpansion \mathbb{R} %EndExpansion$ be defined by $T\left( x\right) =x$, then its extension $\widetilde{T}$ on $M=% %TCIMACRO{\U{211d} }% %BeginExpansion \mathbb{R} %EndExpansion$ is
- A) $\widetilde{T}(x)=x$
- B) $\widetilde{T}(x)=\frac{x+\left\vert x\right\vert }{2}$
- C) All above are valid
- D) $\widetilde{T}(x)=\left\vert x\right\vert$
If a sequence xn→x in a normed space X, then for a bounded linear operator T on X_______.
- A) limn→∞‖Txn-Tx‖>0
- B) ‖Txn-Tx‖≠0
- C) limn→∞‖Txn-Tx‖<0
- D) ‖Txn-Tx‖≤0
Dot product is a
- A) operator.
- B) Mapping.
- C) Function.
- D) Functional.
For all x, y belongs to an an inner product space$$\left\langle {\alpha x,y} \right\rangle = .............\,$$
- A) $$\alpha \left\langle { - x,y} \right\rangle$$
- B) $$\alpha \left\langle {y,x} \right\rangle$$
- C) $$\alpha \left\langle {x, - y} \right\rangle$$
- D) $$\alpha \left\langle {x,y} \right\rangle$$