Forum

Gravitation

What is the source of centripetal force that a planet requires to revolve around the Sun? On what factors does that force depend?

Gravitation

A girl stands on a box having 60 cm length, 40 cm breadth and 20 cm
width in three ways. In which of the following cases, pressure exerted by
the brick will be
(a) maximum when length and breadth form the base
(b) maximum when breadth and width form the base
(c) maximum when width and length form the base
(d) the same in all the above three cases

Gravitation

An object weighs 10 N in air. When immersed fully in water, it weighs only 8 N. The weight of the liquid displaced by the object will be
(a) 2 N
(b) 8 N
(c) 10 N
(d) 12 N

Gravitation

The force of attraction between two unit point masses separated by a unit
distance is called
(a) gravitational potential
(b) acceleration due to gravity
(c) gravitational field
(d) universal gravitational constant

Gravitation

The atmosphere is held to the earth by
(a) gravity
(b) wind
(c) clouds
(d) earth’s magnetic field

Gravitation

Two particles are placed at some distance. If the mass of each of the two
particles is doubled, keeping the distance between them unchanged, the
value of gravitational force between them will be

(a) 1/4 times (b) 4 times (c)1/2 times (d) unchanged

Gravitation

The value of quantity G in the law of gravitation
(a) depends on mass of earth only
(b) depends on radius of earth only
(c) depends on both mass and radius of earth
(d) is independent of mass and radius of the earth

Gravitation

Law of gravitation gives the gravitational force between
(a) the earth and a point mass only
(b) the earth and Sun only
(c) any two bodies having some mass
(d) two charged bodies only

Gravitation

A boy is whirling a stone tied with a string in an horizontal circular path. If the string breaks, the stone
(a) will continue to move in the circular path
(b) will move along a straight line towards the centre of the circular path
(c) will move along a straight line tangential to the circular path
(d) will move along a straight line perpendicular to the circular path away from the boy

Gravitation

The gravitational force between two objects is F. If masses of both objects
are halved without changing distance between them, then the gravitational
force would become
(a) F/4 (b) F/2 (c) F (d) 2 F