CBSE
The angular momentum of a rotating body changes from Ao to 4Ao in 4 minutes. The torque acting on the body is:
3/4 Ao
4Ao
3Ao
3/2Ao
The radius of gyration of a body about an axis at a distance 6 cm from its centre of mass is 10 cm. Then, its radius of gyration about a parallel axis through its centre of mass will be
80 cm
8 cm
0.8 cm
80 m
Point masses 1, 2, 3 and 4 kg are lying at the points (0, 0, 0), (2, 0, 0), (0, 3, 0) and (- 2, -2, 0) respectively. The moment-of inertia of this system about X-axis will be
43 kg-m2
34 kg-m2
27 kg-m2
72 kg-m2
A force of acts on O, the origin of the coordinate systems. The torque about the point (1, -1 ) is
The equation of stationary wave along a stretched string is given by where, x and y are in cm and t in second. The separation between two adjacent nodes is :
1.5 cm
3 cm
6 cm
4 cm
The speed of earth's rotation about its axis is o. Its speed is increased to x times to make the effective acceleration due to gravity equal to zero at the equator. Then x is
1
8.5
17
34
If a spherical ball rolls on a table without slipping the friction of its total energy associated with rotational energy is :
3/5
2/7
2/5
3/7
If the angle between the vectors , the value of the product is equal to
BA2 sinθ
BA2 sinθ cosθ
zero
The moment of inertia of a uniform circular disc of radius R and mass M about an axis passing from the edge of the disc and normal to the disc is
MR2
The moment of inertia of a uniform circular disc of radius R and mass M about an axis passing from the edge of the disc and normal to the disc is
MR2