CBSE
Multiple Choice QuestionsA circular disc X of radius R is made from an iron plate of thickness t, and another disc Y of radius 4R is made from an iron plate of thickness t/4. Then the relation between the moments of inertia IX and IY is
IY = 321X
IY = 161X
IY = IX
IY = 641X
The moments of inertia of two freely rotating bodies A and B are IA and IB respectively IA > IB and their angular momenta are equal. If KA and KB are their kinetic energies then
KA = KB
KA > KB
KA < KB
KA = 2 KB
If the earth is treated as a sphere of radius R and mass M, its angular momentum about the axis of rotation with time period T is
Angular velocity of second hand of a clock is
Sphere, disc and ring are allowed to roll down on an inclined plane from its top, then order in which they reach at the bottom will be
ring, disc, sphere
sphere, disc, ring
disc, ring, sphere
sphere, ring, disc
If we made half the radius of earth, then duration of day will become
6 h
12 h
24 h
3 h
The centre of mass of three particles of mass m1 = 1.0 kg, m2 = 2.0 kg, and m3 = 3.0 kg at the corners of an equilateral triangle 1.0 m on a side, as shown in figure
A system consists of two point masses M and m (< M). The centre of mass of the system is
at the middle of m and M
nearer to M
nearer to m
at the position of large mass
Two perfectly elastic particles A and B of equal masses travelling along the line joining, them with velocity 15 m/s and 20 m/s respectively collide. Their velocities after the elastic collision will be (in m/s) respectively.
0 and 25
5 and 20
10 and 15
20 and 15
If the equation for the displacement of a particle moving on a circular path is given by θ = 2 t3+ 0.5, where θ is in radian and t in second, then the angular velocity of the particle after 2 s from its start is
8 rad/s
12 rad/s
24 rad/s
36 rad/s
