Q.

The weight of a body on the surface of the earth is 100 N. The gravitational force on it when taken at a height from the surface of earth, equal to one-fourth the radius of the earth, is:             [2023]

1 100 N  
2 64 N  
3 50 N  
4 25 N  

Ans.

(2)

 g'=gR2r2=gR2(R+R4)2=16g25

  Weight=1625×100=64 N