AIPMT 2010 Prelims | Rotational Motion Question 54 | Physics

AIPMT 2010 Prelims

MCQ (Single Correct Answer)

-1

A circular disk of moment of inertia $${I_t}$$ is rotating in a horizontal plane, about its symmetry axis, with a constant angular speed $${\omega _i}$$. Another disk of moment of inertia $${I_b}$$ is dropped coaxially onto the rotating disk. Initially the second disk has zero angular speed. Eventually both the disks rotate with a constant angular speed $$\omega $$. The energy lost by the initially rotating disc to friction is

$${1 \over 2}{{I_b^2} \over {\left( {{I_t} + {I_b}} \right)}}\omega _i^2$$

$${1 \over 2}{{I_t^2} \over {\left( {{I_t} + {I_b}} \right)}}\omega _i^2$$

$${{{I_b} - {I_t}} \over {\left( {{I_t} + {I_b}} \right)}}\omega _i^2$$

$${1 \over 2}{{{I_b}{I_t}} \over {\left( {{I_t} + {I_b}} \right)}}\omega _i^2$$

AIPMT 2009

MCQ (Single Correct Answer)

-1

If $$\overrightarrow F $$ is the force acting on a particle having position vector $$\overrightarrow r $$ and $$\overrightarrow \tau $$ be the torque of this force about the origin, then

$$\overrightarrow r .\overrightarrow \tau > 0$$ and $$\overrightarrow F .\overrightarrow \tau < 0$$

$$\overrightarrow r .\overrightarrow \tau = 0$$ and $$\overrightarrow F .\overrightarrow \tau = 0$$

$$\overrightarrow r .\overrightarrow \tau = 0$$ and $$\overrightarrow F .\overrightarrow \tau \ne 0$$

$$\vec r.\vec \tau \ne 0$$ and $$\overrightarrow F .\overrightarrow \tau = 0$$

AIPMT 2009

MCQ (Single Correct Answer)

-1

Four identical thin rods each of mass M and length $$l$$, form a square frame. Moment of inertia of this frame about an axis through the centre of the square and perpendicular to its plane is

$${2 \over 3}M{l^2}$$

$${{13} \over 3}M{l^2}$$

$${1 \over 3}M{l^2}$$

$${4 \over 3}M{l^2}$$

AIPMT 2009

MCQ (Single Correct Answer)

-1

A thin circular ring of mass M and radius R is rotating in a horizontal plane about an axis vertical to its plane with a constant angular velocity $$\omega $$. If two objects each of mass m be attached gently to the opposite ends of a diameter of the ring, the ring will then rotate with an angular velocity

$${{\omega M} \over {M + 2m}}$$

$${{\omega \left( {M + 2m} \right)} \over M}$$

$${{\omega M} \over {M + m}}$$

$${{\omega \left( {M - 2m} \right)} \over {M + 2m}}$$

PREVIOUS NEXT

NEET Subjects

Biology

Botany

Zoology

Human Health and Diseases Body Fluids and Its Circulation Locomotion and Movement Neural Control and Coordination Reproduction in Organisms Reproductive Health Structural Organisation in Animals Digestion and Absorption Excretory Products and Their Elimination Chemical Coordination and Integration Human Reproduction Animal Kingdom Breathing and Exchange of Gases Evolution