MCQ Bank
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
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) 4
- B) 2
- C) 5
- D) 1
What happens to angular velocity when the moment of inertia of an isolated system is doubled to keep the angular momentum constant?
- A) It is halved.
- B) It doubles.
- C) Remains same.
- D) It becomes zero.
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) 0.50
- B) 0.42
- C) 0.15
- D) 0.35
If the center of mass is at origin then the coordinate axes (xyz axes) and the principal axes of the rigid body are.......
- A) coincident
- B) perpendicular
- C)
- D)
If position of a vibrating mass at any time is defined as y(t)=20cos(\frac{3}{4}t). Then the amplitude is
- A) 20
- B) \frac{3}{4}
- C)
- D)
The force field \vec{F}=3x\hat{i}-2y\hat{\hat{j}} is
- A) conservative
- B) non conservative
- C)
- D)
The frequency f of an oscillatory system is equal to
- A) f=-\frac{1}{T}
- B) f=e^{-T}
- C) f=e^{T}
- D) f=\frac{1}{T}
Find the time period T of the vibrating mass with m=5 and f=10
- A) T=\frac{1}{10}
- B) T=\frac{1}{2}
- C)
- D)
If a particle of mass 2 units has position vector \vec{r}=t^{3}\hat{i}+8t\hat{j}-9t\hat{k} then find the force acting on the particle.
- A) 12t\hat{i}
- B) 12t
- C)
- D)
Find the time period T of the vibrating mass with m=10 and f=30
- A) T=\frac{1}{30}
- B) T=\frac{1}{3}
- C)
- D)
A particle moves in a plane in such a way that at any time t its distance from the origin is r=2t+3t^{2} and its angle with positive x-axis is \theta=\sqrt{t}. Find the radial and transverse components of velocity.
- A) 2+6t and \frac{1}{2\sqrt{t}}
- B) 2+6t and (\sqrt{t}+\frac{3}{2}t^{\frac{3}{2}})
- C)
- D)
If a force acts on a particle of constant mass m and \vec{v}_{1}, \vec{v}_{2} are velocities at times t_{1} and t_{2}, respectively. Then the work done by the force is obtained as
- A) The change in kinetic energies, i.e., \frac{1}{2}m\vec{v}_{2}^{2}-\frac{1}{2}m\vec{v}_{1}^{2}
- B) The sum of kinetic energies, i.e., \frac{1}{2}m\vec{v}_{2}^{2}+\frac{1}{2}m\vec{v}_{1}^{2}
- C)
- D)
If position of a vibrating mass at any time is defined as y(t)=10sin(\frac{1}{3}t). Then the amplitude is
- A) 10
- B) \frac{1}{3}
- C)
- D)
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