If the distance between two masses is doubled, the gravitational attraction between them:

1. Is doubled                               

2. Becomes four times

3. Is reduced to half                     

4. Is reduced to a quarter

Which of the following is the evidence to show that there must be a force acting on earth

and directed towards the sun?

1. Deviation of the falling bodies towards east

2. Revolution of the earth around the sun

3. Phenomenon of day and night

4. The apparent motion of the sun around the earth

The gravitational force between two stones of mass 1 kg each separated by a distance of

1 metre in vacuum is

1. Zero                                                 

2. 6.675$\times {10}^{‐5}newton$

3. $6.675\times {10}^{‐11}newton$                 

4. $6.675\times {10}^{‐8}newton$

Two particles of equal mass go round a circle of radius R under the action of their mutual

gravitational attraction. The speed of each particle is

1. $\nu =\frac{1}{2R}\sqrt{\frac{1}{Gm}}$                             

2. $\nu =\sqrt{\frac{Gm}{2R}}$

3. $\nu =\frac{1}{2}\sqrt{\frac{Gm}{R}}$                               

4. $\nu =\sqrt{\frac{4Gm}{R}}$   

The earth (mass = $6\times {10}^{24}kg$ ) revolves round the sun with angular velocity

$2\times {10}^{‐7}rad/s$ in a circular orbit of radius $1.5\times {10}^{8}km$ . The force exerted by the sun on

the earth in Newtons, is

1. $18\times {10}^{25}$                               

2. Zero

3. $27\times {10}^{39}$                               

4. $36\times {10}^{21}$

The gravitational force between two point masses $m_1$  and $m_2$  at separation r is given by $F=k\frac{m_1{m}_2}{r^2}$  The constant k                                                                

1. Depends on system of units only

2. Depends on medium between masses only

3. Depends on both 1 and 2

4. Is independent of both 1 and 2

Who among the following gave first the experimental value of G?

1. Cavendish                               

2. Copernicus

3. Brook Taylor                           

4. None of these

Mass M is divided into two parts xM and $\left(1-x\right)M$ . For a given separation, the value of x

for which the gravitational attraction between the two pieces becomes maximum is

1. $\frac{1}{2}$                                 

2. $\frac{3}{5}$

3. 1                                   

4. 2

Two sphere of mass m and M are situated in air and the gravitational force between them

is F. The space around the masses is now filled with a liquid of specific gravity 3. The

gravitational force will now be

1. F                                        

2. $\frac{F}{3}$  

3. $\frac{F}{9}$                                      

4. 3 F

Earth binds the atmosphere because of:

1. Gravity                                     

2. Oxygen between earth and atmosphere

3. Both 1 and 2

4 None of these