1
JEE Main 2021 (Online) 26th February Evening Shift
+4
-1
A cord is wound round the circumference of wheel of radius r. The axis of the wheel is horizontal and the moment of inertia about it is I. A weight mg is attached to the cord at the end. The weight falls from rest. After falling through a distance 'h', the square of angular velocity of wheel will be :
A
$${{2mgh} \over {I + 2m{r^2}}}$$
B
$${{2mgh} \over {I + m{r^2}}}$$
C
2gh
D
$${{2gh} \over {I + m{r^2}}}$$
2
JEE Main 2021 (Online) 26th February Morning Shift
+4
-1
Four identical solid spheres each of mass 'm' and radius 'a' are placed with their centres on the four corners of a square of side 'b'. The moment of inertia of the system about one side of square where the axis of rotation is parallel to the plane of the square is :
A
$${4 \over 5}m{a^2}$$
B
$${8 \over 5}m{a^2} + m{b^2}$$
C
$${4 \over 5}m{a^2} + 2m{b^2}$$
D
$${8 \over 5}m{a^2} + 2m{b^2}$$
3
JEE Main 2021 (Online) 26th February Morning Shift
+4
-1
A particle is moving with uniform speed along the circumference of a circle of radius R under the action of a central fictitious force F which is inversely proportional to R3. Its time period of revolution will be given by :
A
$$T \propto {R^{{4 \over 3}}}$$
B
$$T \propto {R^{{5 \over 2}}}$$
C
$$T \propto {R^{{3 \over 2}}}$$
D
$$T \propto {R^2}$$
4
JEE Main 2021 (Online) 25th February Evening Shift
+4
-1
A sphere of radius 'a' and mass 'm' rolls along a horizontal plane with constant speed v0. It encounters an inclined plane at angle $$\theta$$ and climbs upward. Assuming that it rolls without slipping, how far up the sphere will travel?

A
$${{v_0^2} \over {2g\sin \theta }}$$
B
$${{7v_0^2} \over {10g\sin \theta }}$$
C
$${2 \over 5}{{v_0^2} \over {g\sin \theta }}$$
D
$${{v_0^2} \over {5g\sin \theta }}$$
JEE Main Subjects
Physics
Mechanics
Electricity
Optics
Modern Physics
Chemistry
Physical Chemistry
Inorganic Chemistry
Organic Chemistry
Mathematics
Algebra
Trigonometry
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Calculus
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