 
       
      
    The ratio of escape velocity of earth   to the escape velocity at a planet 
 whose radius and mean density are twice as that of earth is:
1 : 2
1 : 4
 
                
                  
Escape velocity ( in terms of radius of planet) -
 Escape velocity
Radius of earth
- wherein
 escape velocity=
Option 1)
1 : 2
This option is incorrect
Option 2)
This option is correct
Option 3)
1 : 4
This option is incorrect
Option 4)
This option is incorrect
 
                