JEE Main 2021 (Online) 18th March Evening Shift | Rotational Motion Question 140 | Physics

Consider a uniform wire of mass M and length L. It is bent into a semicircle. Its moment of inertia about a line perpendicular to the plane of the wire passing through the center is :

$${1 \over 4}{{M{L^2}} \over {{\pi ^2}}}$$

$${1 \over 2}{{M{L^2}} \over {{\pi ^2}}}$$

$${2 \over 5}{{M{L^2}} \over {{\pi ^2}}}$$

$${{M{L^2}} \over {{\pi ^2}}}$$

JEE Main 2021 (Online) 18th March Evening Shift

MCQ (Single Correct Answer)

-1

A solid cylinder of mass m is wrapped with an inextensible light string and, is placed on a rough inclined plane as shown in the figure. The frictional force acting between the cylinder and the inclined plane is :

JEE Main 2021 (Online) 18th March Evening Shift Physics - Rotational Motion Question 141 English

JEE Main 2021 (Online) 18th March Evening Shift Physics - Rotational Motion Question 141 English

[The coefficient of static friction, $$\mu$$_s' is 0.4]

5 mg

$${7 \over 2}$$ mg

$${{mg} \over 5}$$

JEE Main 2021 (Online) 18th March Morning Shift

MCQ (Single Correct Answer)

-1

A thin circular ring of mass M and radius r is rotating about its axis with an angular speed $$\omega$$. Two particles having mass m each are now attached at diametrically opposite points. The angular speed of the ring will become :

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

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

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

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

JEE Main 2021 (Online) 17th March Evening Shift

MCQ (Single Correct Answer)

-1

A sphere of mass 2 kg and radius 0.5 m is rolling with an initial speed of 1 ms^-1 goes up an inclined plane which makes an angle of 30$$^\circ$$ with the horizontal plane, without slipping. How long will the sphere take to return to the starting point A?

JEE Main 2021 (Online) 17th March Evening Shift Physics - Rotational Motion Question 143 English