JEE Main 2022 (Online) 25th June Evening Shift | Rotational Motion Question 29 | Physics

JEE Main 2022 (Online) 25th June Evening Shift

MCQ (Single Correct Answer)

-1

A disc with a flat small bottom beaker placed on it at a distance R from its center is revolving about an axis passing through the center and perpendicular to its plane with an angular velocity $$\omega$$. The coefficient of static friction between the bottom of the beaker and the surface of the disc is $$\mu$$. The beaker will revolve with the disc if :

$$R \le {{\mu g} \over {2{\omega ^2}}}$$

$$R \le {{\mu g} \over {{\omega ^2}}}$$

$$R \ge {{\mu g} \over {2{\omega ^2}}}$$

$$R \ge {{\mu g} \over {{\omega ^2}}}$$

JEE Main 2021 (Online) 31st August Evening Shift

MCQ (Single Correct Answer)

-1

A system consists of two identical spheres each of mass 1.5 kg and radius 50 cm at the end of light rod. The distance between the centres of the two spheres is 5 m. What will be the moment of inertia of the system about an axis perpendicular to the rod passing through its midpoint?

18.75 kgm²

1.905 $$\times$$ 10⁵ kgm²

19.05 kgm²

1.875 $$\times$$ 10⁵ kgm²

JEE Main 2021 (Online) 27th August Evening Shift

MCQ (Single Correct Answer)

-1

Two discs have moments of inertia I₁ and I₂ about their respective axes perpendicular to the plane and passing through the centre. They are rotating with angular speeds, $$\omega$$₁ and $$\omega$$₂ respectively and are brought into contact face to face with their axes of rotation coaxial. The loss in kinetic energy of the system in the process is given by :

$${{{I_1}{I_2}} \over {({I_1} + {I_2})}}{({\omega _1} - {\omega _2})^2}$$

$${{{{({I_1} - {I_2})}^2}{\omega _1}{\omega _2}} \over {2({I_1} + {I_2})}}$$

$${{{I_1}{I_2}} \over {2({I_1} + {I_2})}}{({\omega _1} - {\omega _2})^2}$$

$${{{{({\omega _1} - {\omega _2})}^2}} \over {2({I_1} + {I_2})}}$$

JEE Main 2021 (Online) 27th August Morning Shift

MCQ (Single Correct Answer)

-1

A huge circular arc of length 4.4 ly subtends an angle '4s' at the centre of the circle. How long it would take for a body to complete 4 revolution if its speed is 8 AU per second?

Given : 1 ly = 9.46 $$\times$$ 10¹⁵ m

1 AU = 1.5 $$\times$$ 10¹¹ m

4.1 $$\times$$ 10⁸ s

4.5 $$\times$$ 10¹⁰ s

3.5 $$\times$$ 10⁶ s

7.2 $$\times$$ 10⁸ s

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