MCQ Bank
Let 0.01kgm2 be the moment of inertia (about an axis passing through the fixed point) of a rigid body rotating with the angular velocity 20 rad/s. Its kinetic energy will be ____ J.
- A) 1
- B) 4
- C) 5
- D) 2
Let 2kg be the mass and 0.5m be the radius of a right circular cone. Its moment of inertia about the axis of symmetry will be ____kgm2
- A) 0.42
- B) 0.50
- C) 0.35
- D) 0.15
Let 1.2kg be the mass and 3m be the length of a thin solid rod. Its moment of inertia about the axis perpendicular to the rod through the center of mass will be ____kgm2
- A) 5.4
- B) 2.7
- C) 1.8
- D) 3.6
The moment of inertia of a ring of mass 1kg and radius 0.9m about an axis passing through its center will be _____kgm2
- A) 0.81
- B) 0.18
- C) 1.8
- D) 0.45
\[{\text{Let}}\,\vec r = 2\hat i\,{\text{be}}\,{\text{the}}\,{\text{position vector of a particle and}}\,\,\vec p = 3\hat i\,{\text{be its momentum}}\,{\text{then}}\,{\text{the magnitude of angular momentum }}\vec L{\text{ of the particle will be - - - - - }}{\text{.}}\]
- A) 6
- B) 1
- C) 0
- D) 5
A solid metal sphere having the moment of inertia of 0.03kgm2 is rotating with an angular speed of 13.8 rad/s. Its angular momentum would be _____kgm2s-1
- A) 0.414
- B) 0.204
- C) 0.354
- D) 0.440
Let 5kg be the mass and 0.1m be the radius of a solid sphere. Its moment of inertia about the diameter will be ____kgm2
- A) 0.01
- B) 0.02
- C) 0.10
- D) 0.05
{\text{Let}}\,\vec r = 2\hat i\,{\text{be}}\,{\text{the}}\,{\text{position vector of a particle and}}\,\,\vec p = 3\hat i\,{\text{be its momentum}}\,{\text{then}}\,{\text{the magnitude of angular momentum }}\vec L{\text{ of the particle will be - - - - - }}{\text{.}}
- A) 5
- B) 6
- C) 1
- D) 0
$$\begin{gathered} {\text{In }}{\mathbb{R}^n}{\text{, if }}{S_1},{S_2},{S_3} \ldots \,\,{\text{are non - empty closed subsets such that }}{S_1} \supset {S_2} \supset \cdots \; \supset {S_r} \supset \cdots {\text{ and }} \hfill \\ {\text{sup}}\left\{ {\left| {{X_r} - {Y_r}} \right|:{X_r},{Y_r} \in {S_r},r \geqslant 1} \right\} \to 0{\text{ as }}r \to \infty {\text{,then the order of set }}\mathop \cap \limits_{r = 1}^\infty {S_r} = - - - . \hfill \\\ \end{gathered}$$
- A) $$\operatorname{infinite}$$
- B) $${\text{one}}$$
- C) $${\text{finite but more than one}}$$
- D) $${\text{zero}}$$
Let $f\left( {x,y} \right) = \frac{{xy}}{{{x^2} + {y^2}}}$ then the limit of $f$ along the line $y=-x$ as $(x,y)$ approach $(0,0)$ is ______.
- A) $-1/2$
- B) $1/2$
- C) $0$
- D) undefined
${\text{An open disc: }}\left\{ {\left( {x,y} \right):{x^2} + {y^2} < 1} \right\}{\text{ in }}{\mathbb{R}^2}{\text{ is - - - - - - }}{\text{.}}$
- A) ${\text{none of these}}{\text{.}}$
- B) ${\text{connected polygonally}}$
- C) ${\text{disconnected polygonally}}$
- D) ${\text{diconnected}}$
$${\text{In }}{\mathbb{R}^n},{\text{which of the following is true about }}\phi = \left\{ {} \right\}{\text{ and }}A = \left\{ {\left( {{a_1},{a_2}, \ldots ,{a_n}} \right),{a_i} \in \mathbb{R},1 \leqslant i \leqslant n,i \in \mathbb{N}} \right\}?$$
- A) $${\text{Both are Disconnected}}$$
- B) $${\text{Both are Connected}}$$
- C) $$\phi {\text{ is Connected and }}A{\text{ is Disconnected}}$$
- D) $$\phi {\text{ is Disconnected and }}A{\text{ is Connected}}$$
If $\mathop {\lim }\limits_{X \to {X_0}} f\left( X \right)$ exists, then it is _____.
- A) 0
- B) 1
- C) none of these
- D) unique
${\text{A compact set in }}{\mathbb{R}^n}{\text{ is - - - - - - - - - - }}{\text{.}}$
- A) ${\text{closed and bounded}}$
- B) ${\text{open and bounded}}$
- C) ${\text{closed and unbounded}}$
- D) ${\text{open and unbounded}}$
$${\text{Intervals }}\left( {{\text{0,1}}} \right){\text{ and }}\left( {{\text{1,2}}} \right){\text{ are example of disconnected sets in }}\mathbb{R}{\text{ because - - - - - - - }}{\text{.}}$$
- A) $$\left( {{\text{0,1}}} \right) \cap \left( {{\text{1,2}}} \right) = \phi$$
- B) $$\left\{ {{\text{closure of}}\left( {{\text{0,1}}} \right)} \right\} \cap \left( {{\text{1,2}}} \right) = \phi {\text{ and}}\left\{ {{\text{closure of}}\left( {{\text{1,2}}} \right)} \right\} \cap \left( {{\text{0,1}}} \right) = \phi$$
- C)
- D)
$\begin{gathered} {\text{For a non empty closed and bounded subset }}S{\text{ in }}{\mathbb{R}^n},{\text{ if }}{\rm H}{\text{ is the collection open sets such that }} \hfill \\ S \subset \cup \left\{ {H:H \in {\rm H}} \right\},{\text{then by Heine - Borel theorem,}} \hfill \\\ \end{gathered}$
- A) $S \subset \mathop \cup \limits_{\alpha = 1}^n \left\{ {{H_\alpha }:{H_\alpha } \in {\rm H}} \right\}$
- B) $S \subset \mathop \cup \limits_{\lambda \in \Lambda } \left\{ {{H_\lambda }:{H_\lambda } \in {\rm H}} \right\}$
- C) $S \subset \mathop \cup \limits_{\alpha = 1}^\infty \left\{ {{H_\alpha }:{H_\alpha } \in {\rm H}} \right\}$
- D) ${\text{All above are equally valid}}$
$${\text{Set of isolated point(s) of the complement of set }}\left\{ {\left( {x,y} \right): - n < x,y < n,\left( {x,y} \right) \ne \left( {0,0} \right),n \in \mathbb{N}} \right\}{\text{ in }}{\mathbb{R}^{\text{2}}},{\text{is}} - - - - .$$
- A) $$\left\{ {\left( {x,y} \right) \in {\mathbb{R}^2}:x = y = \left| n \right|,n \in \mathbb{N}} \right\}$$
- B) $$\left\{ {\left( {x,y} \right) \in {\mathbb{R}^2}:x = y = \left| n \right|,n \in \mathbb{N}} \right\} \cap \left\{ {\left( {0,0} \right)} \right\}$$
- C) $$\left\{ {\left( {0,0} \right)} \right\}$$
- D) $$\left\{ {\left( {x,y} \right) \in {\mathbb{R}^2}:x = y = \left| n \right|,n \in \mathbb{N}} \right\} \cup \left\{ {\left( {0,0} \right)} \right\}$$
${\text{The set }}\left\{ {\left( {x,y} \right): - n < x,y < n,\left( {x,y} \right) \ne \left( {0,0} \right),n \in \mathbb{N}} \right\}{\text{ is - - - - - - in }}{\mathbb{R}^{\text{2}}}.$
- A) neither open nor closed
- B) open
- C) closed
- D) both open or closed
$${\text{In }}{\mathbb{R}^2},{\text{ the set }}\left\{ {\left( {x,y} \right):\left( {{x^2} + {y^2} \leqslant a} \right)\,\, \vee \,\left( {{x^2} + {y^2} \geqslant b} \right),a < b} \right\}\,{\text{is a region}}{\text{.}}$$
- A) True
- B) False
- C)
- D)
The limit of the function $f(x) = \frac{{xy}}{{{x^2} + {y^2}}}$ by letting $\left( {x,{\rm{ }}y} \right)$approach $\left( {0,{\rm{ }}0} \right)$along the line $y{\rm{ }} = {\rm{ }}x$ is ________.
- A) Undefined
- B) $$- \frac{1}{2}$$
- C) Finite
- D) $$\frac{1}{2}$$