CBSE
Two identical solid copper spheres of radius R are placed in contact with each other. The gravitational attraction between them is proportional to
R2
R-2
R4
R-4
If the mass of moon is of earth's mass, its radius is of earth's radius and if g is acceleration due to gravity on earth, then the acceleration due to gravity on moon is
Which of the following statements about the gravitational constant is true ?
It is a force
It has no unit
It has same value in all systems of units
It does not depend on the nature of the medium in which the bodies are kept
A pellet of mass 1 g is moving with an angular velocity of 1 rad/s along a circle of radius 1 m the centrifugal force is
0.1 dyne
1 dyne
10 dyne
100 dyne
Two point objects of masses 1.5 g and 2.5 g respectively area at a distance of 16 cm apart, the centre of gravity is at a distance x from the object of mass 1.5 g where x is
10 cm
6 cm
13 cm
3 cm
A satellite orbiting the earth in a circular orbit of radius R completes one revolution in 3 h. If orbital radius of geostationarysatellite is 36,000 km, orbital radius of earth is
6000 km
9000 km
12000 km
15000 km
Acceleration due to gravity is g on the surface of the earth. Then the value of the acceleration due to gravity at a height of 32 km above earth's surface is (Assume radius of earth to be 6400 km)
0.99 g
0.8 g
1.01 g
0.9 g
The weight of a body on surface of earth is 12.6 N. When it is raised to a height half the radius of earth its weight will be
2.8 N
5.6 N
12.5 N
25.2 N
The gravitational field is given by E = − xi − 2y2j. When gravitational potential is zero at (0, 0), then the gravitational potential at (2, 1) is
3 unit
6 unit
9 unit
12 unit
On an electron in an atom both electric and gravitational forces are collinear we neglect gravitational force (FG) in comparision to electric force (FE ), because
FE > FG
FN > FE
FE >> FG
FN >> FG